Resonant (RESN) 10-K 14 Mar 22 2021 FY Annual report Financial data

Cover

Cover - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Mar. 14, 2022	Jun. 30, 2021
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2021
Current Fiscal Year End Date	--12-31
Document Transition Report	false
Entity File Number	001-36467
Entity Registrant Name	RESONANT INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	45-4320930
Entity Address, Address Line One	10900 Stonelake Blvd, Suite 100, Office 02-130
Entity Address, City or Town	Austin
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	78759
City Area Code	(805)
Local Phone Number	308-9803
Title of 12(b) Security	Common Stock, $0.001 par value
Trading Symbol	RESN
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	false
Entity Shell Company	false
Entity Public Float			$ 189
Entity Common Stock, Shares Outstanding		67,186,080
Documents Incorporated by Reference [Text Block]	None
Entity Central Index Key	0001579910
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2021
Audit Information [Abstract]
Auditor Name	KPMG LLP
Auditor Location	Irvine, California
Auditor Firm ID	185

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
CURRENT ASSETS
Cash and cash equivalents	$ 21,206	$ 24,968
Accounts receivable	48	208
Prepaid expenses and other current assets	636	511
Restricted cash	55	0
TOTAL CURRENT ASSETS	21,945	25,687
NONCURRENT ASSETS
Property and equipment, net	1,306	1,583
Intangibles, net	2,639	2,119
Restricted cash	0	105
Goodwill	878	911
Operating lease right-of-use assets	1,380	2,012
Financing lease right-of-use asset	160	201
Other assets	53	112
TOTAL NONCURRENT ASSETS	6,416	7,043
TOTAL ASSETS	28,361	32,730
CURRENT LIABILITIES
Accounts payable	1,144	982
Accrued expenses	308	449
Accrued salaries and payroll related expenses	3,079	1,970
Deferred revenue, current portion	1,907	1,721
Operating lease liabilities, current	525	699
Financing lease liability, current	41	30
TOTAL CURRENT LIABILITIES	7,004	5,851
LONG-TERM LIABILITIES
Deferred revenue, net of current portion	4,889	62
Operating lease liabilities, net of current portion	1,078	1,589
Financing lease liability, net of current portion	134	175
TOTAL LIABILITIES	13,105	7,677
Commitments and contingencies
STOCKHOLDERS’ EQUITY
Common stock, $0.001 par value, 100,000,000 authorized and 66,999,853 outstanding as of December 31, 2021 and 59,128,356 outstanding as of December 31, 2020	67	59
Preferred stock, $0.001 par value, 3,000,000 shares authorized and none outstanding as of December 31, 2021 and December 31, 2020	0	0
Additional paid-in capital	202,014	175,813
Accumulated other comprehensive income	51	87
Accumulated deficit	(186,876)	(150,906)
TOTAL STOCKHOLDERS’ EQUITY	15,256	25,053
TOTAL LIABILITIES AND STOCKHOLDERS’ EQUITY	$ 28,361	$ 32,730

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Common stock, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares outstanding (in shares)	66,999,853	59,128,356
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	3,000,000	3,000,000
Preferred stock, shares outstanding (in shares)	0	0

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Income Statement [Abstract]
REVENUES	$ 2,178	$ 3,160
OPERATING EXPENSES
Research and development	22,935	19,477
Sales, marketing and administration	15,197	12,150
TOTAL OPERATING EXPENSES	38,132	31,627
NET OPERATING LOSS	(35,954)	(28,467)
OTHER INCOME (EXPENSE)
Interest and investment income	0	66
Interest and other expense	(15)	(12)
TOTAL OTHER INCOME	(15)	54
LOSS BEFORE INCOME TAXES	(35,969)	(28,413)
Provision for income taxes	(1)	(1)
NET LOSS	(35,970)	(28,414)
Foreign currency translation adjustment	(36)	86
COMPREHENSIVE LOSS	$ (36,006)	$ (28,328)
NET LOSS PER SHARE - BASIC (in dollars per share)	$ (0.58)	$ (0.55)
NET LOSS PER SHARE - DILUTED (in dollars per share)	$ (0.58)	$ (0.55)
Weighted average shares outstanding — basic (in shares)	62,480,340	51,254,329
Weighted average shares outstanding — dilute (in shares)	62,480,340	51,254,329

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Accumulated Other Comprehensive Income
Beginning Balance (in shares) at Dec. 31, 2019		33,156,000
Beginning Balance at Dec. 31, 2019	$ 9,756	$ 33	$ 132,214	$ (122,492)	$ 1
Increase (Decrease) in Stockholders' Equity
Vesting of restricted stock units (in shares)		2,183,000
Vesting of restricted stock units	2	$ 2
Stock-based compensation	6,166		6,166
Sales of common stock, net of offering costs (in shares)		23,776,000
Sales of common stock, net of offering costs	37,447	$ 24	37,423
Exercises of warrants (in shares)		7,000
Exercises of stock options (in shares)		6,000
Exercise of stock options	10		10
Net loss	(28,414)			(28,414)
Foreign currency translation adjustment	$ 86				86
Ending Balance (in shares) at Dec. 31, 2020	59,128,356	59,128,000
Ending Balance at Dec. 31, 2020	$ 25,053	$ 59	175,813	(150,906)	87
Increase (Decrease) in Stockholders' Equity
Vesting of restricted stock units (in shares)		2,174,000
Vesting of restricted stock units	1	$ 1
Stock-based compensation	7,930		7,930
Sales of common stock, net of offering costs (in shares)		5,593,000
Sales of common stock, net of offering costs	17,986	$ 7	17,979
Exercises of stock options (in shares)		105,000
Exercise of stock options	292		292
Net loss	(35,970)			(35,970)
Foreign currency translation adjustment	$ (36)				(36)
Ending Balance (in shares) at Dec. 31, 2021	66,999,853	67,000,000
Ending Balance at Dec. 31, 2021	$ 15,256	$ 67	$ 202,014	$ (186,876)	$ 51

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
CASH FLOWS FROM OPERATING ACTIVITIES
Net loss	$ (35,970)	$ (28,414)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	900	1,000
Stock-based compensation	7,954	5,824
Patent write-offs	641	383
Other	1	6
Operating lease right-of-use asset amortization	632	602
Finance lease right-of-use asset amortization	41	0
Changes in assets and liabilities:
Accounts receivable	160	(130)
Prepaids and other current assets	(125)	(134)
Other assets	59	(44)
Accounts payable	298	(245)
Accrued expenses	(106)	19
Accrued salaries and payroll related expenses	1,085	(55)
Operating lease liabilities	(685)	(501)
Deferred revenue	5,013	52
Net cash used in operating activities	(20,102)	(21,637)
CASH FLOWS FROM INVESTING ACTIVITIES
Purchases of property and equipment	(707)	(705)
Expenditures for patents	(1,254)	(881)
Net cash used in investing activities	(1,961)	(1,586)
CASH FLOWS FROM FINANCING ACTIVITIES
Gross proceeds from the sale of common stock	18,614	40,173
Offering costs in connection with the sale of common stock	(628)	(2,726)
Principal payments on finance lease	(30)	0
Proceeds from exercises of stock options	293	10
Net cash provided by financing activities	18,249	37,457
Effects of currency translation on cash, cash equivalents and restricted cash	2	1
NET INCREASE IN CASH, CASH EQUIVALENTS AND RESTRICTED CASH	(3,812)	14,235
CASH, CASH EQUIVALENTS AND RESTRICTED CASH — Beginning of year	25,073	10,838
CASH, CASH EQUIVALENTS AND RESTRICTED CASH — End of year	21,261	25,073
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Cash paid for taxes	1	2
Cash paid for interest	7	0
SUPPLEMENTAL DISCLOSURE OF NON-CASH ACTIVITIES
Common stock issued in settlement of accrued salaries and payroll related expenses	442	343
Property and equipment included in accounts payable	67	193
Property and equipment included in accrued expenses	33	68
Patents included in accounts payable	210	224
Finance lease liability included in accounts payable	4	0
Property acquired through finance lease obligation	0	204
Operating lease assets obtained in exchange for new lease liabilities	0	114
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents
Cash and cash equivalents	21,206	24,968
Restricted cash	55	105
Total cash, cash equivalents and restricted cash	$ 21,261	$ 25,073

ORGANIZATION AND DESCRIPTION OF

ORGANIZATION AND DESCRIPTION OF BUSINESS	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
ORGANIZATION AND DESCRIPTION OF BUSINESS	ORGANIZATION AND DESCRIPTION OF BUSINESS Overview Resonant Inc. is a late-stage development company located in Austin, Texas, with offices in Goleta, California, San Mateo, California and Anyang, South Korea. We were incorporated in Delaware in January 2012 as a wholly owned subsidiary of Superconductor Technologies Inc., or STI. Resonant LLC, a limited liability company, was formed in California in May 2012. We changed our form of ownership from a limited liability company to a corporation in an exchange transaction in June 2013, when we commenced business. We are the successor of Resonant LLC. We completed our initial public offering, or IPO, on May 29, 2014. On July 6, 2016 we acquired all of the issued and outstanding capital stock of GVR Trade S.A, or GVR. GVR is a wholly owned subsidiary of Resonant Inc. The company operates in one market and segment, the radio frequency filter design industry. The innovative software platform we continue to develop is based on fundamentally new technology that we call WaveX™, to configure and connect resonators, the building blocks of RF filters. Currently, we are leveraging WaveX™ to develop designs targeted for either the Surface Acoustic Wave (SAW) or Temperature Compensated, Surface Acoustic Wave (TC-SAW) manufacturing processes. We also enabled WaveX™ for BAW designs, which has resulted in our invention of a novel resonator structure based on a combination of interdigital transducer (IDT) and piezoelectric layer, XBAR ® , which exhibits performance parameters suitable for 5G,5-7GHz WiFi and UWB applications - high frequency operation, large bandwidth and high power reliability. Using WaveX™ we have developed an IP portfolio of more than 415 patents filed or issued, with more than 265 filed or issued targeting XBAR ® , 5G and high frequency WiFi applications. In addition, with continued requirements for increasing numbers of filter designs our innovative software platform addresses the need for increased designer efficiency, reduced time to market and lower unit costs in the designs of filters for radio frequency, or RF Front-Ends for the mobile device, Customer Premise Equipment (CPE) and Infrastructure industries. The RF Front-End, or RFFE, is the circuitry responsible for analog signal processing and is located between the device’s antenna and its digital circuitry. Filters are a critical component of the RFFE used to select desired radio frequency signals and reject unwanted signals. We believe licensing our designs is the most direct and effective means of validating our IP and IP related libraries and demonstrating the power and accuracy of our WaveX™ multi-physics EDA platform. Our target customers make part, or all of, the RFFE. We intend to retain ownership of our IP, trade secrets and designs, and we expect to be compensated through license fees and royalties either prepaid at contract inception or based on sales of RFFE filters that incorporate our IP, trade secrets and designs. Capital Resources and Liquidity As of December 31, 2021, our accumulated deficit totaled $186.9 million. In the year ended December 31, 2021 our net loss totaled $36.0 million and we used $22.1 million of cash and investments for operating activities, the purchase of property and equipment and expenditures for patents. To date we have not generated significant revenues to enable profitability. We expect to continue to incur significant losses. These factors raise substantial doubt regarding our ability to continue as a going concern. At December 31, 2021 we had cash and cash equivalents of $21.2 million. In the absence of additional customer contracts, we project these cash resources, along with anticipated cash generated from existing customer contracts, will provide sufficient funding into the third quarter of 2022. We are subject to the risks and uncertainties associated with a new business. Our continuance as a going concern is dependent on future profitability. We are actively pursuing expanding our technology portfolio, increasing our revenue opportunities by completing deliverables under current customer contracts and entering into new customer contracts, and efficiently managing operations and exploring cost saving opportunities. We may not be successful in these efforts. As further described in Note 15 - Subsequent Events, on February 14, 2022 we entered into a Merger Agreement for our proposed acquisition by Murata. If the merger is unable to be completed, we may need to seek to raise additional capital from the sale of equity securities or incurrence of indebtedness. There can be no assurance that additional financing will be available to us on acceptable terms, or at all in which case we might be forced to make substantial reductions in our operating expenses which could adversely affect our ability to implement our business plan and ultimately our viability as a company. Even if available, such capital may be dilutive to existing stockholders. The accompanying consolidated financial statements have been prepared on a going concern basis which contemplates the realization of assets and satisfaction of liabilities in the normal course of business. The consolidated financial statements do not include any adjustments relating to the recoverability and classification of recorded asset amounts or the amounts and classification of liabilities that might result from the outcome of this uncertainty.

SUMMARY OF SIGNIFICANT ACCOUNTI

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation and Use of Estimates —The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States, or U.S. GAAP. Significant estimates made in preparing these financial statements include (a) assumptions to calculate the fair values of financial instruments, warrants and equity instruments and other liabilities and the deferred tax asset valuation allowance; (b) the useful lives for depreciable and amortizable assets and (c) the estimated efforts to be expended, as well as our ability to achieve milestones, in connection with our revenue contracts. Actual results could differ from those estimates. Additionally, the global economic effects resulting from the COVID-19 pandemic may cause changes to estimates that would have a material impact on our financial statements, particularly with respect to timing of revenue recognition due to delays in meeting our performance obligations. As of the date of issuance of these financial statements, our results of operations have not been significantly impacted by the COVID-19 pandemic, however, we continue to monitor the situation. In the opinion of management, all adjustments, including normal recurring accruals considered necessary for a fair presentation, have been included. Consolidation - The accompanying financial statements include the accounts of the Company and its wholly-owned subsidiary, GVR. All significant intercompany balances and transactions have been eliminated. Cash and Cash Equivalents —We consider all liquid instruments purchased with a maturity of three months or less to be cash equivalents. Concentration of Credit Risk —We maintain bank accounts at one U.S. financial institution. The U.S. bank accounts are insured by the Federal Deposit Insurance Corporation (FDIC) for up to $250,000 per account owner. GVR, our wholly owned Swiss-based subsidiary maintains checking accounts at one major national financial institution. Additionally, we maintain a checking account with a very minimal balance at one bank in South Korea, which is used to fund payroll and rent in South Korea. Management believes we are not exposed to significant credit risk due to the financial position of the depository institutions in which our deposits are held. Restricted Cash —Restricted cash at December 31, 2021 and 2020 consists of a pledged mutual fund account which is held as collateral against a letter of credit issued in May 2018 in connection with the lease of our offices in Goleta, California. The letter of credit was reissued in November 2020 due to a change in the property owner. No changes were made to the terms of the letter of credit. The terms of the letter of credit allow for a step-down of $50,000 annually upon performance of certain events, primarily no late or defaulted payments. See also Note 9 - Leases, for further details. Fair Value of Financial Instruments —We measure certain financial assets and liabilities at fair value based on the exit price notion, or price that would be received for an asset or paid to transfer a liability, in an orderly transaction between the market participants at the measurement date. The carrying amounts of our financial instruments, including cash equivalents, restricted cash, accounts receivable, accounts payable, and accrued liabilities, approximate fair value due to their short maturities. Accounts Receivable —Trade accounts receivable are stated net of allowances for doubtful accounts. Management estimates the allowance for doubtful accounts based on review and analysis of specific customer balances that may not be collectible, customer payment history and any other customer-specific information that may impact collectability of the receivable. Accounts are considered for write-off when they become past due and when it is determined that the probability of collection is remote. There was no allowance for doubtful accounts at December 31, 2021 and 2020. Property and Equipment —Property and equipment consists of leasehold improvements associated with our corporate offices, software purchased during the normal course of business, equipment and office furniture and fixtures, all of which are recorded at cost. Depreciation and amortization is recorded using the straight-line method over the respective useful lives of the assets ranging from two Intangible Assets, net —Intangible assets are recorded at cost and amortized over the useful life. In the case of business combinations, intangible assets are recorded at fair value. At December 31, 2021 and 2020, intangible assets, net, includes patents and a domain name and other intangible assets purchased as part of our acquisition of GVR, including customer relationships, technology and a trademark. We capitalize certain patent filing costs up to the point of issuance and then amortize the cost over the life of the patent. Costs associated with maintenance or renewal of existing patents are expensed as incurred. Intangible assets are reviewed for impairment whenever events or circumstances indicate that the carrying amount of these assets may not be recoverable. In certain cases, patents may expire or be abandoned as they no longer have a probable economic value. In such cases we write off the capitalized patent costs as patent abandonment costs which are included in research and development expenses. Goodwill— Goodwill represents the difference between the price paid to acquire GVR and the fair value of the assets acquired, net of assumed liabilities. We review goodwill for impairment annually and whenever events or circumstances indicate that the carrying amount of these assets may not be recoverable. Revenue Recognition —Revenue is recognized upon the transfer of control of promised goods or services to customers, generally over time, in an amount that reflects the consideration we expect to receive in exchange for those products or services. Revenue consists primarily of the recognized portion of up-front, non-refundable, prepaid royalties received in connection with filter design projects with customers. Our performance obligations include material rights of the customer for future designs and also current obligations to design a licensable filter in accordance with customer specifications. The license of any completed design is considered part of the performance obligation as the design and licensing of the filter are highly interdependent. We recognize revenue from our design services based on efforts expended to date. At the end of each reporting period, we reassess our measure of progress and adjust revenue when appropriate. We record the expenses related to these projects in the periods incurred and they are included in research and development expense. We evaluate upfront non-refundable prepaid royalties associated with design development contracts to determine whether any of the prepaid amount is attributable to a material right of the customer, or if the payment is solely attributable to the current design contract. If a material right exists, then the upfront payment may require allocation of the amount between the amount attributable to the material right and the amount attributable to the current design contract. In cases that require allocation, we use estimated stand-alone selling prices, as well as other factors, to make the allocation. Amounts attributable to the material right of the customer are initially deferred and then once a design contract is entered into, they are combined with other payments in the contract and are considered the full transaction price for the contract. Upfront non-refundable prepaid royalties attributed to a design contract are generally recognized over a multi-year period of one Upon completion of design services, our customers retain a license over the completed design. The license will typically last for a minimum of two years, and in many cases for the life of the design. Some contracts also include royalties that are sales-based, and we recognize royalty revenue upon shipment, by our customer, of products that include our licensed design. Payment is generally due within 30 days. We apply the exemptions available in ASC 606 to not disclose information about 1) remaining performance obligations that have original expected durations of one year or less and 2) variable consideration that is a sales-based or usage-based royalty. Our performance obligations related to material rights of the customer are expected to be performed in more than one year as the customer has discretion over the timing of entering into additional contracts. Research and Development —Costs and expenses that can be clearly identified as research and development are charged to expense as incurred in accordance with ASC Topic 730-10, Research and Development . Operating Leases —We lease office space and research facilities under operating leases. Certain lease agreements contain free or escalating rent payment provisions. We determine if an arrangement is a lease at lease inception. Operating leases are included in right-of-use (“ROU”) lease assets, other current liabilities (current portion of lease obligations), and long term lease obligations on our balance sheets. ROU lease assets represent our right to use an underlying asset for the lease term and lease obligations represent our obligation to make lease payments arising from the lease. Operating ROU lease assets and obligations are recognized at the commencement date based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, we use an incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The ROU lease asset also includes any lease payments made and excludes lease incentives. We evaluate renewal options at lease inception and on an ongoing basis, and include renewal options which we are reasonably certain to exercise in our expected lease term when classifying leases and measuring lease liabilities. We allocate the consideration between lease and non-lease components and exclude non-lease components from our recognized lease assets and liabilities. Minimum lease payments, including scheduled rent increases, are recognized as lease expenses on a straight-line basis over the applicable lease term. We recognize lease expenses within research and development and sales, marketing and administration expenses on a straight-line basis over the lease term. We are not party to any leases for which we are the lessor. Finance Lease —The finance lease right-of-use asset represents our right to use an underlying asset for the lease term and the finance lease liability represents the present value of lease payments not yet paid. Interest expense on the finance lease is recorded over the lease term and is presented in interest expense, based on the effective interest method. The right-of-use asset is amortized over the term of the related lease. Stock-Based Compensation —We account for employee stock options in accordance with ASC Topic 718, Compensation-Stock Compensation . We use the Black-Scholes option valuation model for estimating fair value at the date of grant. We account for restricted stock units issued at fair value, based on the market price of our stock on the date of grant. Compensation expense is recognized for the portion of the award that is ultimately expected to vest over the period during which the recipient renders the required services to the Company generally using the straight-line single option method. We recognize compensation expense for restricted stock units with market conditions using a graded vesting model, based on the probability of the market condition being met. In the case of award modifications, we recognize the effect of the modification in the period the award is modified. Stock-based compensation expense is included in research and development expenses and general and administrative expenses. Earnings Per Share, or EPS —EPS is computed in accordance with ASC Topic 260, Earnings per Share , and is calculated using the weighted average number of common shares outstanding during each period. Diluted EPS assumes the conversion, exercise or issuance of all potential common stock equivalents unless the effect is to reduce a loss or increase the income per share. Potential common shares consist of the incremental common shares issuable upon the exercise of stock options (using the treasury stock method), the exercise of warrants (using the if-converted method) and the vesting of restricted stock unit awards. Income Taxes —We account for income taxes in accordance with ASC Topic 740, Income Taxes , or ASC 740, which requires the recognition of deferred tax assets and liabilities for the future consequences of events that have been recognized in our consolidated financial statements or tax returns. The measurement of the deferred items is based on enacted tax laws. In the event the future consequences of differences between financial reporting bases and the tax bases of our assets and liabilities result in a deferred tax asset, ASC 740 requires an evaluation of the probability of being able to realize the future benefits indicated by such asset. A valuation allowance related to a deferred tax asset is recorded when it is more likely than not that some portion or the entire deferred tax asset will not be realized. As part of the process of preparing our consolidated financial statements, we are required to estimate our income tax expense in each of the jurisdictions in which we operate. We also assess temporary differences resulting from differing treatment of items for tax and accounting differences. We record a valuation allowance to reduce the deferred tax assets to the amount of future tax benefit that is more likely than not to be realized. Foreign Currency Translation —The Swiss Franc has been determined to be the functional currency for the net assets of our Swiss-based subsidiary. We translate the assets and liabilities to U.S. dollars at each reporting period using exchange rates in effect at the balance sheet date and record the effects of the foreign currency translation in accumulated other comprehensive loss in shareholders' equity. We translate the income and expenses to U.S. dollars at each reporting period using the average exchange rate in effect for the period and record the effects of the foreign currency translation as other comprehensive income (loss) in the consolidated statements of comprehensive loss. Gains and losses resulting from foreign currency transactions are included in net loss in the consolidated statements of comprehensive loss. Recent Accounting Pronouncements Credit Losses— In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments- Credit Losses (Topic 326). In April and November 2019, and February 2020, the FASB issued implementation amendments to the June 2016 ASU (collectively, the amended guidance). The amended guidance replaced the current incurred loss methodology for credit losses with a current expected credit loss ("CECL") model, which requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. The amended guidance expanded the information that an entity must consider in developing its expected credit loss estimates. Additionally, the updates amended the accounting for credit losses for purchased financial assets with a more-than-significant amount of credit deterioration since origination. The amended guidance requires enhanced disclosures to help investors and other financial statement users better understand significant estimates and judgments used in estimated credit losses. Early adoption is permitted. The guidance is effective for us in January 2023. We have no plan to early adopt the guidance and are currently evaluating the impact, which we believe will be immaterial to our consolidated financial statements. With the exception of the new standards discussed above, there have been no other new accounting pronouncements that have significance, or potential significance, to our consolidated financial statements.

REVENUE RECOGNITION

REVENUE RECOGNITION	12 Months Ended
	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
REVENUE RECOGNITION	REVENUE RECOGNITION Contract Liabilities - Our contract liabilities consist of deferred revenue, which represents the revenue associated with remaining performance obligations within our customer contracts. We classify contract liabilities as current or long-term based on the timing of the remaining performance obligations. Our contract liabilities are expected to be recognized over various periods of generally one Summary of changes in contract liabilities for the years ended December 31, 2021 and 2020 (in thousands): 2021 2020 Contract liabilities Contract liabilities, beginning $ 1,783 $ 1,731 Recognition of revenue included in beginning of year contract liabilities (1,475) (1,720) Contract liabilities, net of revenue recognized on contracts during the period 6,688 1,772 Reversal of contract liabilities due to changes in transaction price (200) — Contract liabilities, ending $ 6,796 $ 1,783 We derive a substantial majority of our revenue from a single customer. Effective September 30, 2019 we entered into a collaboration and license agreement with Murata Manufacturing Co., Ltd. (Murata). Pursuant to the collaboration agreement, we have agreed with Murata to collaborate on the development of proprietary circuit designs using our XBAR® technology, and we licensed to Murata rights for products in four specific radio frequencies, or bands. Murata has agreed to pay us up to an aggregate of $9.0 million of total contract consideration in the form of pre-paid royalties for the licensed designs and certain other intellectual property developed in the collaboration, payable in installments over a multi-year development period, with each installment conditional upon our achievement of certain milestones and deliverables acceptable to Murata in its discretion. Murata may terminate the collaboration agreement at any time upon thirty (30) days prior written notice to us. Murata’s rights to our XBAR® technology are exclusive for a period of 30 months, through March 2022, during which period we may not grant to any third party the right to develop, make, have made, use, sell, offer for sale or import any filter or resonator produced through the use of the XBAR® technology for use in mobile communication devices. Under the collaboration agreement, the first payment of $2.0 million was a non-refundable upfront payment received on October 11, 2019. The second payment of $2.5 million was received on September 29, 2020 upon the achievement of the second milestone. As of December 31, 2021 there is $4.5 million remaining potential contract consideration for the achievement of certain milestones outlined in the collaboration and license agreement. On September 30, 2021, we entered into Addendum 1 to the collaboration agreement with Murata, which amends and supplements the collaboration agreement to provide for the development of XBAR®-based designs for up to four additional bands. For rights to these additional bands, Murata has agreed to pay us a $4.0 million non-refundable upfront payment, which was paid on November 10, 2021, and up to an aggregate of between $8.0 million and $36.0 million in pre-paid royalties and other fees, with the amount of the aggregate payments determined based on the complexity of the filter designs selected for development. The future payments will be made in two installments per band over a multi-year development period, with each installment conditional upon our achievement of certain milestones and deliverables acceptable to Murata in its discretion. Murata retains the right to terminate the collaboration agreement and addendum at any time upon thirty (30) days prior written notice to us. We evaluated whether or not Addendum 1 should be treated as a contract modification and we determined that Addendum 1 represented a separate contract and is not a modification to the existing contract. We also considered whether Addendum 1 provided material rights of the customer for future designs and determined that the customer does have material rights to enter into future design development contracts. We allocated the $4.0 million non-refundable upfront payment to each of the four bands at $1.0 million per band as the prepayment provides Murata with a material right to receive future services. Addendum 1 allows Murata with certain time periods in which to choose the next design. Once a design is chosen, the amount of time to complete the design can be up to three years but is highly dependent on the complexity of the chosen design. We entered into a contract for the first of the four designs in October 2021. Addendum 1 allows Murata to choose the second design no later than March 2022, the third design no later than December 2022 and the fourth design no later than March 2023. Under the Murata agreements, we enter into individual statements of work for the designs, each of which have been identified as separate contracts. On October 31, 2021, Murata entered into the first statement of work under Addendum 1 for a total transaction price of $7.0 million. The first non-refundable upfront installment payment of $3.0 million related to this agreement was received on November 10, 2021. In accordance with the guidance of ASC 606, we are required to evaluate the variable consideration within the contract, primarily the milestone payments, and assess the likelihood of achievement in determining our transaction price. Additionally, we must assess whether the variable consideration is constrained and whether recording such variable revenue may result in a significant reversal of revenue due to uncertainties. We continue to evaluate variable consideration for inclusion in the transaction price, and ultimately the revenue recognized, at each reporting period. We recognize revenue for the performance obligations in the Murata contracts over the estimated design development period based on the level of effort expended, as measured by costs incurred relative to total expected costs, as the services are performed. For the periods ended December 31, 2021 and 2020, we have determined that the milestone payments due upon achievement of certain performance criteria are constrained and are thus not included in the transaction price. Therefore, revenue related to those milestone payments has not been recognized. Revenue recognition related to each milestone payment will commence once the constraint is lifted. Consequently, revenue recognition related to the Murata contract will vary from quarter to quarter. During the years ended December 31, 2021 and 2020, we recognized $1.6 million and $2.7 million, respectively, of revenue related to the Murata contracts. For the years ended December 31, 2021 and 2020, the majority of our revenue was recognized over time as services were provided. At December 31, 2021, deferred revenue totaled $6.8 million and will be recognized over the balance of the respective contracts, which is generally the next four years.

PROPERTY AND EQUIPMENT, NET

PROPERTY AND EQUIPMENT, NET	12 Months Ended
	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
PROPERTY AND EQUIPMENT, NET	PROPERTY AND EQUIPMENT, NET Property and equipment, net, consists of the following as of December 31, 2021 and 2020 (in thousands): 2021 2020 Cost: Computers, peripheral and scientific equipment $ 2,331 $ 1,841 Software 2,307 2,307 Leasehold improvements 348 310 Office furniture and equipment 434 434 5,420 4,892 Less: Accumulated depreciation and amortization (4,114) (3,309) Property and equipment, net $ 1,306 $ 1,583

INTANGIBLE ASSETS, NET, AND GOO

INTANGIBLE ASSETS, NET, AND GOODWILL	12 Months Ended
	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
INTANGIBLE ASSETS, NET, AND GOODWILL	INTANGIBLE ASSETS, NET, AND GOODWILLIntangible assets include patent filing costs and other assets (domain name and other intangibles purchased from GVR, including customer relationships, technology and a trademark). Some of the patents were acquired from Superconductor Technologies Inc. as a result of an asset contribution and were recorded at their carryover basis of $216,000 and are being amortized over the remaining useful life of approximately one year as of December 31, 2021. Intangibles acquired as part of the purchase of GVR were initially recorded at their fair value and have been fully amortized. Patent filing costs related to issued patents are amortized over the estimated life of the patent, 11 to 20 years, once they are approved by their respective regulatory agency. There are $1.8 million of pre-issued patent costs not subject to amortization as of December 31, 2021. The domain name is being amortized over the approximate useful life of 10 years. Intangible assets, net, consists of the following as of December 31, 2021 and 2020 (in thousands): 2021 2020 Cost: Patents $ 2,738 $ 2,399 Other (1) 284 291 3,022 2,690 Less: Accumulated amortization (383) (571) Intangible assets, net $ 2,639 $ 2,119 (1) Includes the impact of foreign currency translation. The total impact at December 31, 2021 and 2020 was $7,000 and $17,000, respectively. During the year ended December 31, 2021 and 2020, we expensed $641,000 and $383,000, respectively, related to patents we either abandoned or wrote off as the technology is no longer supported by our current technology. The expense is included in research and development expense. Amortization of intangible assets was $79,000 and $96,000 for the years ended December 31, 2021 and 2020, respectively. The following table summarizes the estimated amortization expense relating to the intangible assets as of December 31, 2021 (in thousands): Years ending December 31, 2022 $ 53 2023 52 2024 50 2025 50 2026 50 2027 and thereafter 561 Total amortization expense $ 816 The change in the carrying amount of goodwill are as follows (in thousands): Goodwill Balance, January 1, 2020 $ 831 Effect of currency translation 80 Balance, December 31, 2020 $ 911 Effect of currency translation (33) Balance, December 31, 2021 $ 878

WARRANTS

WARRANTS	12 Months Ended
	Dec. 31, 2021
Warrants and Rights Note Disclosure [Abstract]
WARRANTS	WARRANTS From time to time, we have issued warrants to purchase shares of common stock. These warrants have been issued in connection with financing transactions and for consulting services. Our warrants are subject to standard anti-dilution provisions applicable to shares of our common stock. Consulting Warrant and Financing Warrant Upon consummation of our Senior Convertible Note financing in June 2013, we issued warrants for business consulting services provided by MDB Capital Group, LLC, or MDB. We issued a 7-year warrant to purchase 222,222 shares of our common stock at an exercise price of $0.01 per share, which we refer to as the Consulting Warrant. The Consulting Warrant was exercisable six months after the completion of our initial public offering, or IPO, in 2014 and expired June 17, 2020. The warrants were exercised at various dates between January 2015 and June 2020. In addition, for placement agent services provided by MDB in connection with our Senior Convertible Note financing, we issued to MDB a 7-year warrant to purchase 208,763 shares of our common stock at an exercise price of $3.35 per share, which we refer to as the Financing Warrant. The Financing Warrant was exercisable six months after the completion of our IPO and expired June 17, 2020. There were a total of 146,233 warrants exercised between February 2015 and November 2017 and 62,530 warrants expired unexercised on June 17, 2020. Private Placement Warrants - September 2017 In September and October 2017, we issued warrants to purchase an aggregate of 1,976,919 shares of our common stock at an exercise price of $4.85 in connection with our private placement sale of 1,976,919 shares of common stock. The sale was completed in two tranches with the first tranche, which closed on September 28, 2017, including 1,745,581 warrants, and the second tranche, which closed on October 2, 2017, including 231,338 warrants. Collectively, we refer to these warrants as Private Placement Warrants - September 2017. The warrants were exercisable for a period commencing 6 months after the closing of the financing and ending on September 28, 2020. There were 10,600 warrants exercised in June 2018, 5,319 warrants cancelled in August 2020 and 1,961,000 warrants which expired unexercised on September 28, 2020. Placement Agent Warrants - 2017 In addition to the Private Placement Warrants - September 2017 issued in connection with our private placement sale of 1,976,919 shares of our common stock, we also issued to the placement agent, warrants to purchase a total of 98,846 shares of our common stock at an exercise price of $4.85 per share. Upon closing of the first tranche on September 28, 2017, we issued 87,279 warrants, and upon closing the second tranche, we issued 11,567 warrants. Collectively, we refer to these warrants as Placement Agent Warrants - 2017. The warrants were exercisable for a period commencing 6 months after the closing of the financing and expired, unexercised, on September 28, 2020. A roll-forward of warrant activity from January 1, 2020 to December 31, 2020 is shown in the following table: Issued and Warrants Issued and Consulting Warrant 6,667 (6,667) (1) — Financing Warrant 62,530 (62,530) (2) — Private Placement Warrants - September 2017 1,966,319 (1,966,319) (3) — Placement Agent Warrants - 2017 98,846 (98,846) (4) — 2,134,362 (2,134,362) — (1) During the year ended December 31, 2020, there were 6,667 warrants that were exercised through a cashless exercise which netted 6,640 shares being issued. (2) During the year ended December 31, 2020, there were 62,530 warrants that expired. (3) During the year ended December 31, 2020, there were 5,319 warrants that were cancelled and 1,961,000 warrants that expired. (4) During the year ended December 31, 2020, there were 98,846 warrants that expired. There were no issued or outstanding warrants for the year ended December 31, 2021.

STOCKHOLDERS_ EQUITY AND EARNIN

STOCKHOLDERS’ EQUITY AND EARNINGS PER SHARE	12 Months Ended
	Dec. 31, 2021
Stockholders' Equity Note [Abstract]
STOCKHOLDERS’ EQUITY AND EARNINGS PER SHARE	STOCKHOLDERS’ EQUITY AND EARNINGS PER SHARE Common Stock Pursuant to our amended and restated certificate of incorporation, we are authorized to issue 100,000,000 shares of common stock. Holders of our common stock are entitled to dividends as and when declared by the board of directors, subject to rights and holders of all classes of stock outstanding having priority rights to dividends. There have been no dividends declared to date. Each share of common stock is entitled to one vote. On February 6, 2020, we entered into an underwriting agreement relating to an underwritten public offering of 16,666,667 shares of the Company’s common stock, $0.001 par value, at an offering price to the public of $1.50 per share. Pursuant to the underwriting agreement, the Company granted the underwriters a 30-day option to purchase up to an additional 2,500,000 shares of common stock on the same terms and conditions. The underwriters exercised their option with respect to all 2,500,000 additional shares on February 10, 2020. We consummated the sale of an aggregate of 19,166,667 shares of our common stock, including the 2,500,000 shares subject to the underwriters’ over-allotment option, on February 11, 2020. We received gross proceeds of approximately $28.8 million, including $201,000 for 134,000 shares purchased by Park City Capital, a significant shareholder. Net proceeds of approximately $26.4 million after deducting the underwriting discount and expenses paid by us. On August 14, 2020, we entered into an At-The-Market Equity Offering Sales Agreement pursuant to which we may offer and sell shares of our common stock from time to time (the "ATM equity program"). We initially registered the offer and sale of up to $25.0 million of our common stock under the ATM equity program in August 2020. In May 2021, we registered an additional $50.0 million of our common stock under the ATM equity program. During 2020 we sold an aggregate of 4,609,701 shares of common stock under the ATM equity program at an average price of $2.48 per share, for gross proceeds of $11.4 million and net proceeds of $11.0 million. During 2021 we sold an aggregate of 5,592,570 shares of common stock under the ATM equity program at an average price of $3.33 per share for gross proceeds of $18.6 million and net proceeds of $18.1 million. Offering costs, including commissions and other expenses, are reflected in net proceeds. Preferred Stock Pursuant to our amended and restated certificate of incorporation, we are authorized to issue 3,000,000 shares of preferred stock. The board of directors has the authority, without action by our stockholders, to designate and issue shares of preferred stock in one or more series and to fix the rights, preferences, privileges and restrictions thereof. To-date, no preferred shares have been issued. Earnings Per Share The following table presents the number of shares excluded from the calculation of diluted net loss per share attributable to common stockholders as of December 31, 2021 and 2020: 2021 2020 Common stock options 945,076 1,140,975 Non-vested restricted stock units 3,426,628 3,038,785 Total shares excluded from net loss per share attributable to common stockholders 4,371,704 4,179,760

STOCK-BASED COMPENSATION

STOCK-BASED COMPENSATION	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
STOCK-BASED COMPENSATION	STOCK-BASED COMPENSATION 2014 Omnibus Incentive Plan In January 2014, our board of directors approved the 2014 Omnibus Incentive Plan and amended and restated the plan in March 2014. Our stockholders approved the Amended and Restated 2014 Omnibus Incentive Plan, or the 2014 Plan, in March 2014. Our 2014 Plan initially permitted the issuance of equity-based instruments covering up to a total of 1,400,000 shares of common stock. Our board of directors and stockholders approved an increase of 1,300,000 shares in June 2016, an additional increase of 3,250,000 shares in June 2017, an additional increase of 4,000,000 shares in June 2019 and an additional increase of 5,000,000 shares in June 2020, bringing the total shares allowed under the plan to 14,950,000. As of December 31, 2021, there were 3,259,944 shares available to issue under the 2014 Plan. Stock Options Options granted in 2021 and 2020 have a term of ten years and vest quarterly over sixteen quarters. The options granted in 2021 had an aggregate grant date fair value of $20,000 and options granted in 2020 had an aggregate grant date fair value of $177,000 utilizing the Black-Scholes option valuation model. We estimated the fair value of stock options awarded during the years ended December 31, 2021 and 2020 using the Black-Scholes option valuation model. The fair values of stock options granted for the years were estimated using the following assumptions: Option Grants Awarded During the Year Ended December 31, 2021 Option Grants Awarded During the Year Ended December 31, 2020 Stock Price $5.31 $1.74 to $2.85 Dividend Yield 0% 0% Expected Volatility 88% 70% to 83% Risk-free interest rate 0.72% 0.36% to 1.52% Expected Term 7 years 7 years Stock-based compensation expense related to stock options was $166,000 and $236,000 for the years ended December 31, 2021 and 2020, respectively. Beginning January 1, 2021, we recognize forfeitures as they occur. For the year ended December 31, 2020, we applied a forfeiture rate of ten percent, which is reflected in our stock-based compensation expense related to stock options. Stock Option Award Activity The following is a summary of our stock option activity during the year ended December 31, 2021: Number of Weighted Weighted Weighted Outstanding, January 1, 2021 1,140,975 $ 4.46 $ 2.81 5.69 Granted 5,000 5.31 4.04 9.04 Exercised (105,098) 2.79 1.69 — Canceled/Forfeited (95,801) 4.90 3.02 — Outstanding, December 31, 2021 945,076 $ 4.60 $ 2.92 4.68 Number of Weighted Weighted Weighted Exercisable, January 1, 2021 955,302 $ 4.74 $ 2.96 5.10 Vested 74,198 3.44 2.32 6.66 Exercised (105,098) 2.79 1.69 — Canceled/Forfeited (75,192) 5.55 3.35 — Exercisable, December 31, 2021 849,210 $ 4.79 $ 3.02 4.32 As of December 31, 2021 there were 95,866 unvested stock options with a weighted average grant date fair value of $2.03. The weighted-average grant date fair value per share of employee stock options granted during the year ended December 31, 2020 was $1.68. As of December 31, 2020 there were 185,673 unvested stock options with a grant date fair value of $2.05. As of December 31, 2021, there was $162,000 of unrecognized compensation expense related to unvested stock options, which is expected to be recognized over a weighted average vesting period of approximately 1.8 years. Both the aggregate intrinsic value of outstanding options and options exercisable as of December 31, 2021 was zero, as there were no options whose exercise price was less than the closing fair market value of our common stock of $1.71 per share. The total intrinsic value of options exercised in the year ended December 31, 2021 was $374,000. The aggregate intrinsic value of outstanding options and options exercisable as of December 31, 2020 were $170,000 and $130,000, respectively, representing options whose exercise price was less than the closing fair market value of our common stock of $2.65 per share. There were no excess tax benefits realized for tax deductions from stock options exercised during the years ended December 31, 2021 and 2020 as we have recorded a full valuation allowance against our deferred income taxes. Restricted Stock Units Activity We account for restricted stock units (RSUs) issued to employees and non-employees at fair value, based on the market price of our stock on the date of grant. RSUs issued in connection with our employee incentive programs typically vest within 10 days of grant. All other RSUs, primarily issued as long term incentives, generally vest annually over three A summary of restricted stock unit activity for the year ended December 31, 2021 is as follows: Number of Weighted-Average Outstanding at January 1, 2021 3,038,785 $ 2.53 Granted 2,851,443 4.38 Vested (2,173,829) 3.51 Forfeited (289,771) 3.88 Outstanding at December 31, 2021 3,426,628 $ 3.44 A summary of restricted stock unit activity for the year ended December 31, 2020 is as follows: Number of Weighted-Average Outstanding at January 1, 2020 2,556,004 $ 3.38 Granted 3,091,206 2.04 Vested (2,183,163) 2.82 Forfeited (425,262) 2.57 Outstanding at December 31, 2020 3,038,785 $ 2.53 As of December 31, 2021, there was $8.6 million of unrecognized compensation expense related to unvested restricted stock unit agreements which is expected to be recognized over a weighted-average period of approximately 2.1 years. For restricted stock unit awards subject to graded vesting, we recognize compensation cost on a straight-line basis over the service period for the entire award. The total fair value of awards vested during the years ended December 31, 2021 and December 31, 2020 was $7.6 million and $6.2 million, respectively. Market-based Awards In August 2016, we granted 250,000 market-based restricted stock units to an executive. The restricted stock units are subject to market-based vesting requirements, measured quarterly, based on the average of (a) the average high daily trading price of our common stock for each trading day during the last month of the applicable calendar quarter and (b) the average low daily trading price of our common stock for each trading day during the last month of the applicable calendar quarter, each as reported by The Nasdaq Stock Market, LLC. The restricted stock units are eligible to be earned on a quarterly basis based on a linear interpolation of the applicable share price, or in the case of a liquidation event, on the day of (or in connection with) such liquidation event based on the applicable transaction price. The share price on the date of issuance was $5.06 per share. In June 2019, the market-based award was modified to increase the number of restricted stock units to 500,000 and to decrease the applicable share price. Additionally, the performance period was extended to September 30, 2022. The share price on the date of modification was $2.73 per share. Once earned, the restricted stock units vest 50% on the date such restricted stock units become earned and 50% on September 30, 2022. To determine the fair value of the award, we used a Monte Carlo simulation, which simulates future stock prices for the Company and, hence, shares vested, pursuant to the award. A key input into the model is the expected volatility for our stock. This estimate considered the historical volatility of our stock as well as the stock price volatility of guideline public companies. The fair value was determined to be $74,000 at the original grant date, and was $147,000 as of the modification date. For each of the years ended December 31, 2021 and 2020, we recognized $42,000 of stock compensation expense in connection with this award, which is included in sales, marketing and administration expenses. The unamortized expense related to this award is $31,500 and is expected to be recognized over 0.75 years. In December 2019, we granted 200,000 market-based restricted stock units to an executive. The restricted stock units are subject to the same market-based vesting requirements discussed for the award granted in August 2016 and modified in June 2019. The share price on the date of issuance was $2.15 per share and the fair value was determined to be $26,000 using a Monte Carlo simulation. For each of the years ended December 31, 2021 and 2020, we recognized $9,000 of stock compensation expense, in connection with this award, which is included in research and development expenses. The unamortized expense related to this award is $6,500 and is expected to be recognized over 0.75 years. Incentive Bonus Awards We provide eligible employees, including executives, the opportunity to earn bonus awards upon achievement of predetermined performance goals and objectives. The purpose is to reward attainment of company goals and/or individual performance objectives, with award opportunities expressed as a percentage of base salary. Bonuses can be measured and paid quarterly and/or annually, and are paid in cash, equity or a combination of cash and equity, in the discretion of our compensation committee. If paid in the form of equity, the expense is included in the above disclosures for stock options or restricted stock units as applicable. As of December 31, 2021 and December 31, 2020, there were no accrued incentives that were settled in the form of equity. Total stock-based compensation recorded in the consolidated statements of comprehensive loss is allocated as follows (in thousands): Year Ended December 31, 2021 Year Ended December 31, 2020 Research and development $ 3,779 $ 2,753 Sales, marketing and administration 4,175 3,071 Total stock-based compensation $ 7,954 $ 5,824

LEASES

LEASES	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
LEASES	LEASES We lease facilities under two non-cancelable operating leases. The leases expire between January 2022 and November 2024 and include renewal provisions for two On May 1, 2020 we entered into an amendment for one of our non-cancelable facilities operating leases, under which certain rent payments were deferred and the term of the lease was extended by three months to November 30, 2024. The base rent was deferred for three months and the deferred amount will be repaid over the remaining balance of the modified lease term. In addition, operating expenses were deferred for three months and the deferred amount was paid upon true-up of operating expenses, which occurred in April 2021. We evaluated the amendment under the provisions of ASU No. 2016-02, Leases (Topic 842) , as well as subsequently issued interpretive guidance, and elected to account for the concessions as if no changes to the lease contract were made. In our evaluation we considered the total amount of lease payments both before and after the amendment and determined they are substantially the same. One facility operating lease requires us to maintain a cash security deposit of $50,000 and also a $55,000 letter of credit in favor of the lessor. The letter of credit was originally for $200,000 at lease inception and steps down $50,000 at each anniversary date if there have been no monetary defaults. The letter of credit is secured by a pledge in favor of the issuing bank of a $55,000 mutual fund account which is classified as restricted cash in our balance sheet. Lease renewal options are at our discretion. No renewal options have been recognized in our right-of-use assets and lease liabilities as of December 31, 2021. Our lease agreements do not require material variable minimum lease payments, residual value guarantees or restrictive covenants. Effective as of October 6, 2021, we entered into a Sublease Agreement with Sonim Technologies, Inc. for approximately 8,416 square feet of office space in San Mateo, California to serve as a replacement to our current satellite office for employees residing in the San Francisco Bay area. The rent under the sublease is $12,500 per month, and the term will commence on January 17, 2022 and expire on January 31, 2023. We have an option to renew the sublease for an additional one-year term for rent of $13,250 per month. Alan Howe, a member of our board of directors, is a director of Sonim Technologies, and Robert Tirva, a member of our board of directors, is an executive officer of Sonim Technologies. In December 2020, we entered into a lease for lab equipment. The lease is for 60 months and bears an interest rate of 5.99%. After evaluation of the lease under ASU No. 2016-02, Leases (Topic 842) , we determined the lease to be a finance lease. We recorded a right-of-use asset and lease liability of $204,000 upon inception of the lease. The Company's weighted average remaining lease term and weighted average discount rate as of December 31, 2021 is shown below: Weighted average remaining lease term (years) Operating leases 2.88 Finance lease 3.92 Weighted average discount rate (%) Operating leases 4.75 % Finance lease 5.99 % Minimum future maturities of lease liabilities recognized on the consolidated balance sheets as of December 31, 2021 (in thousands): Operating Leases Finance Lease 2022 $ 586 $ 50 2023 584 50 2024 544 50 2025 — 46 Total minimum lease payments $ 1,714 $ 196 Less: interest (111) (21) Present value of minimum lease payments $ 1,603 $ 175 Operating lease and non-lease costs were $1,219,000 for the year ended December 31, 2021, of which $804,000 and $415,000 are included in research and development expenses and sales, marketing and administration expenses, respectively. Operating lease and non-lease costs were $1,132,000 for the year ended December 31, 2020, of which $812,000 and $320,000 are included in research and development expenses and sales, marketing and administration expenses, respectively. Operating lease costs include short-term rents and other operating expenses. Cash paid for amounts included in the measurement of operating lease liabilities were $777,000 and $613,000 for the years ended December 31, 2021and 2020, respectively, which is included in operating activities in the consolidated statement of cash flows.
LEASES	LEASES We lease facilities under two non-cancelable operating leases. The leases expire between January 2022 and November 2024 and include renewal provisions for two On May 1, 2020 we entered into an amendment for one of our non-cancelable facilities operating leases, under which certain rent payments were deferred and the term of the lease was extended by three months to November 30, 2024. The base rent was deferred for three months and the deferred amount will be repaid over the remaining balance of the modified lease term. In addition, operating expenses were deferred for three months and the deferred amount was paid upon true-up of operating expenses, which occurred in April 2021. We evaluated the amendment under the provisions of ASU No. 2016-02, Leases (Topic 842) , as well as subsequently issued interpretive guidance, and elected to account for the concessions as if no changes to the lease contract were made. In our evaluation we considered the total amount of lease payments both before and after the amendment and determined they are substantially the same. One facility operating lease requires us to maintain a cash security deposit of $50,000 and also a $55,000 letter of credit in favor of the lessor. The letter of credit was originally for $200,000 at lease inception and steps down $50,000 at each anniversary date if there have been no monetary defaults. The letter of credit is secured by a pledge in favor of the issuing bank of a $55,000 mutual fund account which is classified as restricted cash in our balance sheet. Lease renewal options are at our discretion. No renewal options have been recognized in our right-of-use assets and lease liabilities as of December 31, 2021. Our lease agreements do not require material variable minimum lease payments, residual value guarantees or restrictive covenants. Effective as of October 6, 2021, we entered into a Sublease Agreement with Sonim Technologies, Inc. for approximately 8,416 square feet of office space in San Mateo, California to serve as a replacement to our current satellite office for employees residing in the San Francisco Bay area. The rent under the sublease is $12,500 per month, and the term will commence on January 17, 2022 and expire on January 31, 2023. We have an option to renew the sublease for an additional one-year term for rent of $13,250 per month. Alan Howe, a member of our board of directors, is a director of Sonim Technologies, and Robert Tirva, a member of our board of directors, is an executive officer of Sonim Technologies. In December 2020, we entered into a lease for lab equipment. The lease is for 60 months and bears an interest rate of 5.99%. After evaluation of the lease under ASU No. 2016-02, Leases (Topic 842) , we determined the lease to be a finance lease. We recorded a right-of-use asset and lease liability of $204,000 upon inception of the lease. The Company's weighted average remaining lease term and weighted average discount rate as of December 31, 2021 is shown below: Weighted average remaining lease term (years) Operating leases 2.88 Finance lease 3.92 Weighted average discount rate (%) Operating leases 4.75 % Finance lease 5.99 % Minimum future maturities of lease liabilities recognized on the consolidated balance sheets as of December 31, 2021 (in thousands): Operating Leases Finance Lease 2022 $ 586 $ 50 2023 584 50 2024 544 50 2025 — 46 Total minimum lease payments $ 1,714 $ 196 Less: interest (111) (21) Present value of minimum lease payments $ 1,603 $ 175 Operating lease and non-lease costs were $1,219,000 for the year ended December 31, 2021, of which $804,000 and $415,000 are included in research and development expenses and sales, marketing and administration expenses, respectively. Operating lease and non-lease costs were $1,132,000 for the year ended December 31, 2020, of which $812,000 and $320,000 are included in research and development expenses and sales, marketing and administration expenses, respectively. Operating lease costs include short-term rents and other operating expenses. Cash paid for amounts included in the measurement of operating lease liabilities were $777,000 and $613,000 for the years ended December 31, 2021and 2020, respectively, which is included in operating activities in the consolidated statement of cash flows.

INCOME TAXES

INCOME TAXES	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
INCOME TAXES	INCOME TAXES The provision for income taxes by jurisdiction consists of the following as of December 31, 2021and 2020 (in thousands): 2021 2020 U.S. federal: Current $ — $ — Deferred — — Total U.S. federal — — U.S. state and local: Current 1 1 Deferred — — Total U.S. state and local 1 1 Foreign: Current — — Deferred — — Total foreign — — Provision for income taxes $ 1 $ 1 Income taxes differ from the amounts computed by applying the U.S. federal income tax rate to pretax income (loss) before income taxes as a result of the following (in thousands): 2021 2020 Expected income tax benefit $ (7,554) $ (5,966) State income tax (benefit), net of federal benefit (2,812) (1,961) Valuation allowance 10,761 7,732 Permanent differences: Stock options 255 353 Research & development credit (617) (560) Adjustment to deferred taxes (55) 400 Foreign rate differential 1 (1) Other 22 4 Provision for income taxes $ 1 $ 1 For each of the years ended December 31, 2021 and 2020 we recorded a net income tax provision of $1,000. Deferred income tax reflects the tax effects of temporary differences that gave rise to significant portions of our deferred tax assets and liabilities. Deferred income tax consists of the following (in thousands): Balance, December 31, 2021 Balance, December 31, 2020 U.S. federal and state deferred tax assets—long term: Accrued payroll $ 200 $ 180 Accrued expenses 54 53 Fixed assets 36 17 Charitable contributions 28 14 Intangibles 473 431 Research & development credit 4,874 3,830 Net operating loss 44,772 35,279 Stock compensation 658 519 Lease liabilities 499 700 New jobs credit 8 8 Total long-term assets 51,602 41,031 Total deferred tax assets 51,602 41,031 U.S. federal and state deferred tax liabilities—long term: Right of use assets (432) (621) Total deferred tax liabilities (432) (621) Net deferred tax assets - long term 51,170 40,410 Less: Valuation allowance (51,170) (40,410) Net deferred tax assets $ — $ — Foreign deferred tax assets—long term: Net operating loss $ 8 $ 6 Total foreign deferred tax assets 8 6 Less: Valuation allowance (8) (6) Net deferred tax assets $ — $ — We recorded a full valuation allowance against our U.S. federal and state net deferred tax assets at December 31, 2021 and December 31, 2020. In determining the need for a valuation allowance, we reviewed all available evidence pursuant to the requirements of FASB ASC Topic 740, Income Taxes . Based upon our assessment of all available evidence, we have concluded that it is more likely than not that the net deferred tax assets will not be realized. For the year ended December 31, 2021, the valuation allowance increased by $10.8 million. For the year ended December 31, 2020, the valuation allowance increased by $7.7 million. As of December 31, 2021, we had federal net operating loss carryforwards of approximately $159.4 million, state net operating loss carryforwards of approximately $162.1 million and foreign net operating loss carryforwards of $52,000 in Switzerland. In accordance with the 2017 Tax Act, the $112.5 million federal net operating loss carryforwards generated on or after January 1, 2018 will not expire and will be limited to 80% usage. The federal net operating loss carryforwards generated prior to January 1, 2018 will begin to expire in 2033, and the state net operating loss carryforwards will begin to expire in 2033. Our ability to utilize federal net operating loss carryforwards may be limited in the event that a change in ownership, as defined in Section 382 of the Internal Revenue Code, occurs in the future. States may vary in its conformity to Section 382 of the Internal Revenue Code. In the event a change of ownership occurs, it will limit the annual usage of the carryforwards in future years. In 2014 and 2017 ownership changes, as defined in Section 382 of the Internal Revenue Code, occurred which resulted in annual limitations on our federal net operating loss carryforwards; however, we believe it is more likely than not that none of the federal net operating loss carryforwards will expire as a result of the limitations under Section 382. We recognize interest and penalties related to income tax matters in income taxes, and there were none during the years ended December 31, 2021 and 2020. As of December 31, 2021 and 2020, no liability for unrecognized tax benefits was required to be reported. ASC 740 guidance requires us to identify, evaluate and measure all uncertain tax positions taken or to be taken on tax returns and to record liabilities for the amount of these positions that may not be sustained, or may only partially be sustained, upon examination by the relevant taxing authorities. Although we believe that our estimates and judgments are reasonable, actual results may differ from these estimates. Some or all of these judgments are subject to review by the taxing authorities. For the year ended December 31, 2021, we had uncertain tax positions of $1.2 million as a result of research and development tax credits claimed on our annual tax returns. We had uncertain tax positions of $1.0 million for the year ended December 31, 2020. Our annual income taxes and the determination of the resulting deferred tax assets and liabilities involve a significant amount of judgment. Our judgments, assumptions and estimates relative to current income taxes take into account current tax laws, their interpretation of current tax laws and possible outcomes of future audits conducted by domestic tax authorities. We operate within federal and state taxing jurisdictions and are subject to audit in these jurisdictions. These audits can involve complex issues which may require an extended period of time to resolve. We are currently not being examined by any tax authorities. We are subject to taxation in the United States, California, Massachusetts and Switzerland. As of December 31, 2021, our tax years remain open to examination by the taxing authorities for all years since our incorporation in 2013.

COMMITMENTS AND CONTINGENCIES

COMMITMENTS AND CONTINGENCIES	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	COMMITMENTS AND CONTINGENCIES Purchase Commitments —We have non-cancelable purchasing commitments that we incur in the ordinary course of business. The purchase commitments covered by these agreements are for less than one year and aggregate to $0.7 million as of December 31, 2021. Legal Proceedings —We may, from time to time, be party to litigation and subject to claims incident to the ordinary course of business. As our growth continues, we may become party to an increasing number of litigation matters and claims. The outcome of litigation and claims cannot be predicted with certainty, and the resolution of any future matters could materially affect our future financial position, results of operations or cash flows. Legal fees and other costs associated with such actions are expensed as incurred. We assess, in conjunction with our legal counsel, the need to record a liability for litigation and contingencies. Litigation accruals are recorded when and if it is determined that a loss related matter is both probable and reasonably estimable. Material loss contingencies that are reasonably possible of occurrence, if any, are subject to disclosure. We evaluate developments in legal proceedings and other matters on a quarterly basis. As of December 31, 2021 and 2020, there was no litigation or contingency with at least a reasonable possibility of a material loss. No losses have been recorded during the years ended December 31, 2021 and 2020, respectively, with respect to litigation or loss contingencies. Intellectual Property Indemnities —We indemnify certain customers and manufacturers against liability arising from third-party claims of intellectual property rights infringement related to our products. These indemnities may appear in license agreements, development agreements and manufacturing agreements, may not be limited in amount or duration and generally survive the expiration date of the contract. Given that the amount of any potential liabilities related to such indemnities cannot be determined until an infringement claim has been made, we are unable to determine the maximum amount of losses that we could incur related to such indemnifications. Director and Officer Indemnities and Contractual Guarantees —We have entered into indemnification agreements with our directors and executive officers, which require us to indemnify such individuals to the fullest extent permitted by Delaware law. Our indemnification obligations under such agreements are not limited in amount or duration. Certain costs incurred in connection with such indemnifications may be recovered under certain circumstances under various insurance policies. Given that the amount of any potential liabilities related to such indemnities cannot be determined until a lawsuit has been filed, we are unable to determine the maximum amount of losses that we could incur relating to such indemnities. We have also entered into severance and change in control agreements with certain of our executives. These agreements provide for the payment of specific compensation benefits to such executives upon the termination of their employment with us. Guarantees and Indemnities —In the normal course of business, we are occasionally required to undertake indemnification for which we may be required to make future payments under specific circumstances. We review our exposure under such obligations no less than annually, or more frequently as required. The amount of any potential liabilities related to such obligations cannot be accurately determined until a formal claim is filed. Historically, any such amounts that become payable have not had a material negative effect on our business, financial condition or results of operations. We maintain general and product liability insurance which may provide a source of recovery to us in the event of an indemnification claim.

RELATED PARTY TRANSACTIONS

RELATED PARTY TRANSACTIONS	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
RELATED PARTY TRANSACTIONS	RELATED PARTY TRANSACTIONS In August 2019, we entered into a consulting agreement with a member of our board of directors. Under the agreement, the board member would provide technical advisory services for cash payments totaling $50,000 paid in twelve equal monthly installments as well as an award of restricted stock units equal in value to $100,000 as of the grant date. In the event the board member continues to perform services in subsequent years, the Company will issue new grants equal to no less than $100,000 worth of restricted stock units in January of each additional year with such grants vesting at the end of each year so long as the services are still being provided. The agreement is cancellable at any time by either the Company or the board member. Services have continued to be provided since inception of the agreement. During the year ended December 31, 2021, we recorded expenses of $50,000 in connection with the cash compensation portion of the consulting agreement, which is included in research and development expenses. During the year ended December 31, 2020, we recorded expenses of $50,000 in connection with the cash compensation portion of the consulting agreement, which is included in research and development expenses. Additionally, during the year ended December 31, 2021, we recorded $100,000 related to the restricted stock unit awards, which is included in general and administrative expenses. During the year ended December 31, 2020, we recorded $102,000 related to restricted stock awards, which is included in general and administrative expense. As of December 31, 2021, there was $4,000 due to the board member under his consulting agreement. In October 2021, we entered into a Sublease Agreement with Sonim Technologies, Inc. for approximately 8,416 square feet of office space in San Mateo, California to serve as a replacement to our current satellite office for employees residing in the San Francisco Bay area. The rent under the sublease is $12,500 per month. The term commences on January 17, 2022 and expires on January 31, 2023 with an option to renew the sublease for an additional one-year term for rent of $13,250 per month. Alan Howe, a member of our board of directors, is a director of Sonim Technologies, and Robert Tirva, a member of our board of directors, is an executive officer of Sonim Technologies.

EMPLOYEE BENEFIT PLAN

EMPLOYEE BENEFIT PLAN	12 Months Ended
	Dec. 31, 2021
Retirement Benefits [Abstract]
EMPLOYEE BENEFIT PLAN	EMPLOYEE BENEFIT PLAN We have a 401(k) Savings Retirement Plan that covers substantially all domestic employees who meet the plan’s eligibility requirements and provides for an employee elective contribution and employer matching contributions. We recorded matching contributions to the retirement plan of $524,000 and $494,000 for the years ended December 31, 2021 and 2020, respectively.

SEGMENTS AND GEOGRAPHIC INFORMA

SEGMENTS AND GEOGRAPHIC INFORMATION	12 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
SEGMENTS AND GEOGRAPHIC INFORMATION	SEGMENTS AND GEOGRAPHIC INFORMATION We operate in a single segment to design radio frequency filters. In making operating decisions, the Chief Operating Decision Maker, our Chief Executive Officer, primarily considers consolidated financial performance and allocates resources accordingly. The table below presents our revenue by geographic area (in thousands) and is categorized based on the location of the customer. 2021 2020 Japan $ 1,598 $ 2,716 China 289 406 Other 291 38 Total revenue $ 2,178 $ 3,160

SUBSEQUENT EVENTS

SUBSEQUENT EVENTS	12 Months Ended
	Dec. 31, 2021
Subsequent Events [Abstract]
SUBSEQUENT EVENTS	SUBSEQUENT EVENTS Merger Agreement On February 14, 2022, we entered into an Agreement and Plan of Merger (the "Merger Agreement") by and among us and Murata Electronics North America, Inc. ("Murata"), and PJ Cosmos Acquisition Company, Inc. a wholly owned subsidiary of Murata ("Purchaser"). Murata is a wholly-owned subsidiary of Murata Manufacturing Co., Ltd. Pursuant to the terms and subject to the conditions set forth in the Merger Agreement, on February 28, 2022 Purchaser commenced a cash tender offer (the “Offer”) to purchase all of the outstanding shares of the Company’s common stock, par value $0.001 per share (the “Shares”), at a purchase price of $4.50 per Share, net to the tendering stockholder in cash, without interest and less any required withholding taxes (the “Per Share Amount”). Upon successful completion of the Offer, and subject to the terms and conditions of the Merger Agreement, Purchaser will be merged with and into us (the “Merger”), and we will survive the Merger as a wholly-owned subsidiary of Murata. At the effective time of the Merger (the “Effective Time”), each outstanding Share (other than Shares held by (i) Resonant, Murata or their respective subsidiaries immediately prior to the Effective Time and (ii) stockholders of Resonant who have properly and validly perfected their statutory appraisal rights under the Delaware General Corporation Law (“DGCL”)) will automatically be converted into the right to receive the Per Share Amount on the terms and subject to the conditions set forth in the Merger Agreement. The initial expiration date of the Offer is the time that is one minute following 11:59p.p., New York City time, on March 25, 2022, subject to extension in certain circumstances as required or permitted by the Merger Agreement and applicable law. The Offer is subject to the satisfaction of customary conditions, including, among others, that (i) at least that number of Shares validly tendered and not withdrawn (other than Shares tendered by guaranteed delivery where actual delivery has not occurred), when added to any Shares already owned by Murata or any of its controlled subsidiaries, if any, equal a majority of the outstanding Shares as of immediately prior to the time at which Purchaser first accepts for payment the Shares tendered in the Offer, (ii) the expiration or termination of the applicable waiting period under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and (iii) the other conditions set forth in Annex A to the Merger Agreement have been satisfied or waived. The Merger Agreement contemplates that the Merger will be effected pursuant to Section 251(h) of the DGCL, which permits completion of the Merger upon the collective ownership by Murata, Purchaser and any other subsidiary of Murata of one share more than 50% of the number of Shares that are then issued and outstanding, and if the Merger is so effected pursuant to Section 251(h) of the DGCL, no stockholder vote will be required to consummate the Merger. The Merger Agreement places limitations on our ability to engage in certain types of transactions without Murata’s consent during the period between the signing of the Merger Agreement and the Effective Time. During this period, we may not raise additional capital through the sale of securities or incur debt. Further, other than in transactions in the ordinary course of business or within specified dollar limits and certain other limited exceptions, we generally may not acquire other businesses, make investments in other persons, or sell, lease, or encumber our assets. The Merger Agreement contains certain termination rights for Resonant and Murata. Among such rights, and subject to certain limitations, either Resonant or Murata may terminate the Merger Agreement if the Offer is not completed by June 14, 2022, which date may be extended to August 14, 2022 under certain circumstances. The Merger Agreement contains certain termination rights for each of us and Murata. Among such rights, and subject to certain limitations, either Resonant or Murata may terminate the Merger Agreement if the Offer is not completed by June 14, 2022, which date may be extended to August 14, 2022 under certain circumstances. The Merger Agreement also provides that upon termination of the Merger Agreement under specified circumstances, we may be required to pay Murata a termination fee of $11.2 million or Murata may be required to pay us a termination fee of $15.0 million. In addition, upon termination of the Merger Agreement under specified circumstances, we may be required to reimburse Murata for up to $3.0 million of expenses. Any expenses we reimburses Murata would be offset against and reduce the amount of the termination fee otherwise payable by us to Murata. Legal Proceedings Following announcement of the Merger Agreement and commencement of the Offer, the following lawsuits have been filed against the Company and members of the Company’s Board of Directors and certain members of senior management: United States District Court Stockholder Litigation On March 1, 2022, Danny Key, a purported stockholder of the Company, filed a complaint against the Company and each member of the Company’s Board of Directors in the United States District Court for the Southern District of New York, captioned Danny Key vs. Resonant, Inc., et al., Case No. 1:22-cv-01708 (the “Key Complaint”). The Key Complaint alleges that the defendants violated Sections 14(e), 14(d), and 20(a) of the Exchange Act by omitting and/or misrepresenting material information in the Solicitation/Recommendation Statement on Schedule 14D-9 of Resonant Inc. filed with the SEC on February 28, 2022 (the “Schedule 14D-9”) (concerning, among other things, the sale process, the Company’s financial projections, and financial valuation analyses provided by the Company’s financial advisors) in connection with the proposed transaction contemplated by the Offer. The Key Complaint seeks, among other things, an order enjoining consummation of the transaction; rescission or rescissory damages in the event the transaction is consummated; an order directing the Board of Directors to disseminate a revised Schedule 14D-9; and an award of plaintiff’s costs, including reasonable allowance for attorneys’ fees and experts’ fees. Between March 4, 2022 and March 11, 2022, five additional complaints were filed in federal district court in New York and one additional complaint was filed in federal district court in Pennsylvania, in each case by purported stockholders of the Company: (i) Miles Weiss vs. Resonant, Inc., et al., Case No. 1:22-cv-01202-FB-PK (E.D.N.Y.) (the “Weiss Complaint”), (ii) Brian Jones vs. Resonant, Inc., et al., Case No. 1:22-cv-01855 (S.D.N.Y.) (the “Jones Complaint”), (iii) Ken Callen vs. Resonant, Inc., et al., Case No. 1:22-cv-01903 (S.D.N.Y.) (the “Callen Complaint”), (iv) Thomas Valenti vs. Resonant, Inc., et al., Case No. 1:22-cv-01244 (E.D.N.Y.) (the “Valenti Complaint”), (v) Benny Ruff vs. Resonant, Inc., et al., Case No. 2:22-cv-00861(E.D. Pa.) (the “Ruff Complaint”), and (vi) Jeffrey D. Justice, II vs. Resonant Inc. et al., Case No. 1:22-cv-01353 (E.D.N.Y.) (the “Justice Complaint”). The Weiss Complaint was voluntarily dismissed by the plaintiff on March 11, 2022. Each of the Jones Complaint, the Valenti Complaint, the Ruff Complaint and the Justice Complaint asserts claims under Sections 14(e), 14(d), and 20(a) of the Exchange Act, and Rule 14d-9 promulgated thereunder, alleging, among other things, that defendants omitted certain material facts related to the transaction from the Schedule 14D-9. The Callen Complaint, which asserts claims under Sections 14(e) and 20(a) of the Exchange Act, alleges, in addition, that the disclosure regarding the Company’s financial projections is false and misleading in view of alleged prior statements by the Company on certain earnings calls. Each of the Jones Complaint, the Valenti Complaint, the Callen Complaint, the Ruff Complaint and the Justice Complaint seeks, among other things, to enjoin the defendants from consummating the transaction, rescissory damages should the transaction not be enjoined, and an award of attorneys’ fees and experts’ fees. The Company and the Board believe that the allegations in each of the foregoing complaints are without merit and intend to defend their position. However, a negative outcome in any lawsuit could have a material adverse effect on the Company if it results in preliminary or permanent injunctive relief or rescission of the Merger Agreement. In addition, although the Company has directors and officers liability insurance, the Company anticipates that it will incur significant expense within its self-insured retention under that insurance. The Company is not currently able to predict the outcome of any of the lawsuits with any certainty. Additional lawsuits may be filed against the Company, the Board of Directors or management in connection with the Merger Agreement and the Schedule 14D-9.

SUMMARY OF SIGNIFICANT ACCOUN_2

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)	12 Months Ended
	Dec. 31, 2021
Accounting Policies [Abstract]
Basis of Presentation and Use of Estimates	Basis of Presentation and Use of Estimates —The accompanying financial statements have been prepared in accordance with accounting principles generally accepted in the United States, or U.S. GAAP. Significant estimates made in preparing these financial statements include (a) assumptions to calculate the fair values of financial instruments, warrants and equity instruments and other liabilities and the deferred tax asset valuation allowance; (b) the useful lives for depreciable and amortizable assets and (c) the estimated efforts to be expended, as well as our ability to achieve milestones, in connection with our revenue contracts. Actual results could differ from those estimates. Additionally, the global economic effects resulting from the COVID-19 pandemic may cause changes to estimates that would have a material impact on our financial statements, particularly with respect to timing of revenue recognition due to delays in meeting our performance obligations. As of the date of issuance of these financial statements, our results of operations have not been significantly impacted by the COVID-19 pandemic, however, we continue to monitor the situation. In the opinion of management, all adjustments, including normal recurring accruals considered necessary for a fair presentation, have been included.
Consolidation	Consolidation - The accompanying financial statements include the accounts of the Company and its wholly-owned subsidiary, GVR. All significant intercompany balances and transactions have been eliminated.
Cash and Cash Equivalents	Cash and Cash Equivalents —We consider all liquid instruments purchased with a maturity of three months or less to be cash equivalents.
Concentration of Credit Risk	Concentration of Credit Risk—We maintain bank accounts at one U.S. financial institution. The U.S. bank accounts are insured by the Federal Deposit Insurance Corporation (FDIC) for up to $250,000 per account owner. GVR, our wholly owned Swiss-based subsidiary maintains checking accounts at one major national financial institution. Additionally, we maintain a checking account with a very minimal balance at one bank in South Korea, which is used to fund payroll and rent in South Korea. Management believes we are not exposed to significant credit risk due to the financial position of the depository institutions in which our deposits are held.
Restricted Cash	Restricted Cash —Restricted cash at December 31, 2021 and 2020 consists of a pledged mutual fund account which is held as collateral against a letter of credit issued in May 2018 in connection with the lease of our offices in Goleta, California. The letter of credit was reissued in November 2020 due to a change in the property owner. No changes were made to the terms of the letter of credit. The terms of the letter of credit allow for a step-down of $50,000 annually upon performance of certain events, primarily no late or defaulted payments. See also Note 9 - Leases, for further details.
Fair Value of Financial Instruments	Fair Value of Financial Instruments —We measure certain financial assets and liabilities at fair value based on the exit price notion, or price that would be received for an asset or paid to transfer a liability, in an orderly transaction between the market participants at the measurement date. The carrying amounts of our financial instruments, including cash equivalents, restricted cash, accounts receivable, accounts payable, and accrued liabilities, approximate fair value due to their short maturities.
Accounts Receivable	Accounts Receivable—Trade accounts receivable are stated net of allowances for doubtful accounts. Management estimates the allowance for doubtful accounts based on review and analysis of specific customer balances that may not be collectible, customer payment history and any other customer-specific information that may impact collectability of the receivable. Accounts are considered for write-off when they become past due and when it is determined that the probability of collection is remote.
Property and Equipment	Property and Equipment —Property and equipment consists of leasehold improvements associated with our corporate offices, software purchased during the normal course of business, equipment and office furniture and fixtures, all of which are recorded at cost. Depreciation and amortization is recorded using the straight-line method over the respective useful lives of the assets ranging from two
Intangible Assets, net	Intangible Assets, net —Intangible assets are recorded at cost and amortized over the useful life. In the case of business combinations, intangible assets are recorded at fair value. At December 31, 2021 and 2020, intangible assets, net, includes patents and a domain name and other intangible assets purchased as part of our acquisition of GVR, including customer relationships, technology and a trademark. We capitalize certain patent filing costs up to the point of issuance and then amortize the cost over the life of the patent. Costs associated with maintenance or renewal of existing patents are expensed as incurred. Intangible assets are reviewed for impairment whenever events or circumstances indicate that the carrying amount of these assets may not be recoverable. In certain cases, patents may expire or be abandoned as they no longer have a probable economic
Goodwill	Goodwill—Goodwill represents the difference between the price paid to acquire GVR and the fair value of the assets acquired, net of assumed liabilities. We review goodwill for impairment annually and whenever events or circumstances indicate that the carrying amount of these assets may not be recoverable.
Revenue Recognition	Revenue Recognition —Revenue is recognized upon the transfer of control of promised goods or services to customers, generally over time, in an amount that reflects the consideration we expect to receive in exchange for those products or services. Revenue consists primarily of the recognized portion of up-front, non-refundable, prepaid royalties received in connection with filter design projects with customers. Our performance obligations include material rights of the customer for future designs and also current obligations to design a licensable filter in accordance with customer specifications. The license of any completed design is considered part of the performance obligation as the design and licensing of the filter are highly interdependent. We recognize revenue from our design services based on efforts expended to date. At the end of each reporting period, we reassess our measure of progress and adjust revenue when appropriate. We record the expenses related to these projects in the periods incurred and they are included in research and development expense. We evaluate upfront non-refundable prepaid royalties associated with design development contracts to determine whether any of the prepaid amount is attributable to a material right of the customer, or if the payment is solely attributable to the current design contract. If a material right exists, then the upfront payment may require allocation of the amount between the amount attributable to the material right and the amount attributable to the current design contract. In cases that require allocation, we use estimated stand-alone selling prices, as well as other factors, to make the allocation. Amounts attributable to the material right of the customer are initially deferred and then once a design contract is entered into, they are combined with other payments in the contract and are considered the full transaction price for the contract. Upfront non-refundable prepaid royalties attributed to a design contract are generally recognized over a multi-year period of one Upon completion of design services, our customers retain a license over the completed design. The license will typically last for a minimum of two years, and in many cases for the life of the design. Some contracts also include royalties that are sales-based, and we recognize royalty revenue upon shipment, by our customer, of products that include our licensed design. Payment is generally due within 30 days.
Research and Development	Research and Development —Costs and expenses that can be clearly identified as research and development are charged to expense as incurred in accordance with ASC Topic 730-10, Research and Development .
Operating and Finance Leases	Operating Leases —We lease office space and research facilities under operating leases. Certain lease agreements contain free or escalating rent payment provisions. We determine if an arrangement is a lease at lease inception. Operating leases are included in right-of-use (“ROU”) lease assets, other current liabilities (current portion of lease obligations), and long term lease obligations on our balance sheets. ROU lease assets represent our right to use an underlying asset for the lease term and lease obligations represent our obligation to make lease payments arising from the lease. Operating ROU lease assets and obligations are recognized at the commencement date based on the present value of lease payments over the lease term. As most of our leases do not provide an implicit rate, we use an incremental borrowing rate based on the information available at the commencement date in determining the present value of lease payments. The ROU lease asset also includes any lease payments made and excludes lease incentives. We evaluate renewal options at lease inception and on an ongoing basis, and include renewal options which we are reasonably certain to exercise in our expected lease term when classifying leases and measuring lease liabilities. We allocate the consideration between lease and non-lease components and exclude non-lease components from our recognized lease assets and liabilities. Minimum lease payments, including scheduled rent increases, are recognized as lease expenses on a straight-line basis over the applicable lease term. We recognize lease expenses within research and development and sales, marketing and administration expenses on a straight-line basis over the lease term. We are not party to any leases for which we are the lessor. Finance Lease —The finance lease right-of-use asset represents our right to use an underlying asset for the lease term and the finance lease liability represents the present value of lease payments not yet paid. Interest expense on the finance lease is recorded over the lease term and is presented in interest expense, based on the effective interest method. The right-of-use asset is amortized over the term of the related lease.
Stock-Based Compensation	Stock-Based Compensation —We account for employee stock options in accordance with ASC Topic 718, Compensation-Stock Compensation . We use the Black-Scholes option valuation model for estimating fair value at the date of grant. We account for restricted stock units issued at fair value, based on the market price of our stock on the date of grant. Compensation expense is recognized for the portion of the award that is ultimately expected to vest over the period during which the recipient renders the required services to the Company generally using the straight-line single option method. We recognize compensation expense for restricted stock units with market conditions using a graded vesting model, based on the probability of the market condition being met. In the case of award modifications, we recognize the effect of the modification in the period the award is modified. Stock-based compensation expense is included in research and development expenses and general and administrative expenses.
Earnings Per Share, or EPS	Earnings Per Share, or EPS —EPS is computed in accordance with ASC Topic 260, Earnings per Share , and is calculated using the weighted average number of common shares outstanding during each period. Diluted EPS assumes the conversion, exercise or issuance of all potential common stock equivalents unless the effect is to reduce a loss or increase the income per share. Potential common shares consist of the incremental common shares issuable upon the exercise of stock options (using the treasury stock method), the exercise of warrants (using the if-converted method) and the vesting of restricted stock unit awards.
Income Taxes	Income Taxes —We account for income taxes in accordance with ASC Topic 740, Income Taxes
Foreign Currency Translation	Foreign Currency Translation —The Swiss Franc has been determined to be the functional currency for the net assets of our Swiss-based subsidiary. We translate the assets and liabilities to U.S. dollars at each reporting period using exchange rates in effect at the balance sheet date and record the effects of the foreign currency translation in accumulated other comprehensive loss in shareholders' equity. We translate the income and expenses to U.S. dollars at each reporting period using the average exchange rate in effect for the period and record the effects of the foreign currency translation as other comprehensive income (loss) in the consolidated statements of comprehensive loss. Gains and losses resulting from foreign currency transactions are included in net loss in the consolidated statements of comprehensive loss.
Recent Accounting Pronouncements	Recent Accounting Pronouncements Credit Losses— In June 2016, the FASB issued ASU No. 2016-13, Financial Instruments- Credit Losses (Topic 326). In April and November 2019, and February 2020, the FASB issued implementation amendments to the June 2016 ASU (collectively, the amended guidance). The amended guidance replaced the current incurred loss methodology for credit losses with a current expected credit loss ("CECL") model, which requires the measurement of all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts. The amended guidance expanded the information that an entity must consider in developing its expected credit loss estimates. Additionally, the updates amended the accounting for credit losses for purchased financial assets with a more-than-significant amount of credit deterioration since origination. The amended guidance requires enhanced disclosures to help investors and other financial statement users better understand significant estimates and judgments used in estimated credit losses. Early adoption is permitted. The guidance is effective for us in January 2023. We have no plan to early adopt the guidance and are currently evaluating the impact, which we believe will be immaterial to our consolidated financial statements. With the exception of the new standards discussed above, there have been no other new accounting pronouncements that have significance, or potential significance, to our consolidated financial statements.

REVENUE RECOGNITION (Tables)

REVENUE RECOGNITION (Tables)	12 Months Ended
	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Contract with Customer, Asset and Liability	Summary of changes in contract liabilities for the years ended December 31, 2021 and 2020 (in thousands): 2021 2020 Contract liabilities Contract liabilities, beginning $ 1,783 $ 1,731 Recognition of revenue included in beginning of year contract liabilities (1,475) (1,720) Contract liabilities, net of revenue recognized on contracts during the period 6,688 1,772 Reversal of contract liabilities due to changes in transaction price (200) — Contract liabilities, ending $ 6,796 $ 1,783

PROPERTY AND EQUIPMENT, NET (Ta

PROPERTY AND EQUIPMENT, NET (Tables)	12 Months Ended
	Dec. 31, 2021
Property, Plant and Equipment [Abstract]
Schedule of Property and Equipment, Net	Property and equipment, net, consists of the following as of December 31, 2021 and 2020 (in thousands): 2021 2020 Cost: Computers, peripheral and scientific equipment $ 2,331 $ 1,841 Software 2,307 2,307 Leasehold improvements 348 310 Office furniture and equipment 434 434 5,420 4,892 Less: Accumulated depreciation and amortization (4,114) (3,309) Property and equipment, net $ 1,306 $ 1,583

INTANGIBLE ASSETS, NET, AND G_2

INTANGIBLE ASSETS, NET, AND GOODWILL (Tables)	12 Months Ended
	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	Intangible assets, net, consists of the following as of December 31, 2021 and 2020 (in thousands): 2021 2020 Cost: Patents $ 2,738 $ 2,399 Other (1) 284 291 3,022 2,690 Less: Accumulated amortization (383) (571) Intangible assets, net $ 2,639 $ 2,119 (1) Includes the impact of foreign currency translation. The total impact at December 31, 2021 and 2020
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table summarizes the estimated amortization expense relating to the intangible assets as of December 31, 2021 (in thousands): Years ending December 31, 2022 $ 53 2023 52 2024 50 2025 50 2026 50 2027 and thereafter 561 Total amortization expense $ 816
Schedule of Goodwill	The change in the carrying amount of goodwill are as follows (in thousands): Goodwill Balance, January 1, 2020 $ 831 Effect of currency translation 80 Balance, December 31, 2020 $ 911 Effect of currency translation (33) Balance, December 31, 2021 $ 878

WARRANTS (Tables)

WARRANTS (Tables)	12 Months Ended
	Dec. 31, 2021
Warrants and Rights Note Disclosure [Abstract]
Schedule of Warrant Activity	A roll-forward of warrant activity from January 1, 2020 to December 31, 2020 is shown in the following table: Issued and Warrants Issued and Consulting Warrant 6,667 (6,667) (1) — Financing Warrant 62,530 (62,530) (2) — Private Placement Warrants - September 2017 1,966,319 (1,966,319) (3) — Placement Agent Warrants - 2017 98,846 (98,846) (4) — 2,134,362 (2,134,362) — (1) During the year ended December 31, 2020, there were 6,667 warrants that were exercised through a cashless exercise which netted 6,640 shares being issued. (2) During the year ended December 31, 2020, there were 62,530 warrants that expired. (3) During the year ended December 31, 2020, there were 5,319 warrants that were cancelled and 1,961,000 warrants that expired.

STOCKHOLDERS_ EQUITY AND EARN_2

STOCKHOLDERS’ EQUITY AND EARNINGS PER SHARE (Tables)	12 Months Ended
	Dec. 31, 2021
Stockholders' Equity Note [Abstract]
Schedule of Repurchase Agreements	The following table presents the number of shares excluded from the calculation of diluted net loss per share attributable to common stockholders as of December 31, 2021 and 2020: 2021 2020 Common stock options 945,076 1,140,975 Non-vested restricted stock units 3,426,628 3,038,785 Total shares excluded from net loss per share attributable to common stockholders 4,371,704 4,179,760

STOCK-BASED COMPENSATION (Table

STOCK-BASED COMPENSATION (Tables)	12 Months Ended
	Dec. 31, 2021
Share-based Payment Arrangement [Abstract]
Schedule of Fair Values of Stock Options Granted, Estimated Using Black-Scholes Option Valuation Model Assumptions	The fair values of stock options granted for the years were estimated using the following assumptions: Option Grants Awarded During the Year Ended December 31, 2021 Option Grants Awarded During the Year Ended December 31, 2020 Stock Price $5.31 $1.74 to $2.85 Dividend Yield 0% 0% Expected Volatility 88% 70% to 83% Risk-free interest rate 0.72% 0.36% to 1.52% Expected Term 7 years 7 years
Summary of Stock Option Activity	The following is a summary of our stock option activity during the year ended December 31, 2021: Number of Weighted Weighted Weighted Outstanding, January 1, 2021 1,140,975 $ 4.46 $ 2.81 5.69 Granted 5,000 5.31 4.04 9.04 Exercised (105,098) 2.79 1.69 — Canceled/Forfeited (95,801) 4.90 3.02 — Outstanding, December 31, 2021 945,076 $ 4.60 $ 2.92 4.68 Number of Weighted Weighted Weighted Exercisable, January 1, 2021 955,302 $ 4.74 $ 2.96 5.10 Vested 74,198 3.44 2.32 6.66 Exercised (105,098) 2.79 1.69 — Canceled/Forfeited (75,192) 5.55 3.35 — Exercisable, December 31, 2021 849,210 $ 4.79 $ 3.02 4.32
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	A summary of restricted stock unit activity for the year ended December 31, 2021 is as follows: Number of Weighted-Average Outstanding at January 1, 2021 3,038,785 $ 2.53 Granted 2,851,443 4.38 Vested (2,173,829) 3.51 Forfeited (289,771) 3.88 Outstanding at December 31, 2021 3,426,628 $ 3.44 A summary of restricted stock unit activity for the year ended December 31, 2020 is as follows: Number of Weighted-Average Outstanding at January 1, 2020 2,556,004 $ 3.38 Granted 3,091,206 2.04 Vested (2,183,163) 2.82 Forfeited (425,262) 2.57 Outstanding at December 31, 2020 3,038,785 $ 2.53
Schedule of Stock-Based Compensation	Total stock-based compensation recorded in the consolidated statements of comprehensive loss is allocated as follows (in thousands): Year Ended December 31, 2021 Year Ended December 31, 2020 Research and development $ 3,779 $ 2,753 Sales, marketing and administration 4,175 3,071 Total stock-based compensation $ 7,954 $ 5,824

LEASES (Tables)

LEASES (Tables)	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Lessee, Operating Lease, Lease Terms	The Company's weighted average remaining lease term and weighted average discount rate as of December 31, 2021 is shown below: Weighted average remaining lease term (years) Operating leases 2.88 Finance lease 3.92 Weighted average discount rate (%) Operating leases 4.75 % Finance lease 5.99 %
Operating Lease Maturity	Minimum future maturities of lease liabilities recognized on the consolidated balance sheets as of December 31, 2021 (in thousands): Operating Leases Finance Lease 2022 $ 586 $ 50 2023 584 50 2024 544 50 2025 — 46 Total minimum lease payments $ 1,714 $ 196 Less: interest (111) (21) Present value of minimum lease payments $ 1,603 $ 175
Finance Leases Maturity	Minimum future maturities of lease liabilities recognized on the consolidated balance sheets as of December 31, 2021 (in thousands): Operating Leases Finance Lease 2022 $ 586 $ 50 2023 584 50 2024 544 50 2025 — 46 Total minimum lease payments $ 1,714 $ 196 Less: interest (111) (21) Present value of minimum lease payments $ 1,603 $ 175

INCOME TAXES (Tables)

INCOME TAXES (Tables)	12 Months Ended
	Dec. 31, 2021
Income Tax Disclosure [Abstract]
Schedule of Income Taxes By Jurisdiction	The provision for income taxes by jurisdiction consists of the following as of December 31, 2021and 2020 (in thousands): 2021 2020 U.S. federal: Current $ — $ — Deferred — — Total U.S. federal — — U.S. state and local: Current 1 1 Deferred — — Total U.S. state and local 1 1 Foreign: Current — — Deferred — — Total foreign — — Provision for income taxes $ 1 $ 1
Schedule of Income Taxes Differ From The Amounts Computed By Applying The U.S. Federal Income tax rate to pretax income (loss) before income Taxes	Income taxes differ from the amounts computed by applying the U.S. federal income tax rate to pretax income (loss) before income taxes as a result of the following (in thousands): 2021 2020 Expected income tax benefit $ (7,554) $ (5,966) State income tax (benefit), net of federal benefit (2,812) (1,961) Valuation allowance 10,761 7,732 Permanent differences: Stock options 255 353 Research & development credit (617) (560) Adjustment to deferred taxes (55) 400 Foreign rate differential 1 (1) Other 22 4 Provision for income taxes $ 1 $ 1
Schedule of Components of Deferred Income Tax	Deferred income tax consists of the following (in thousands): Balance, December 31, 2021 Balance, December 31, 2020 U.S. federal and state deferred tax assets—long term: Accrued payroll $ 200 $ 180 Accrued expenses 54 53 Fixed assets 36 17 Charitable contributions 28 14 Intangibles 473 431 Research & development credit 4,874 3,830 Net operating loss 44,772 35,279 Stock compensation 658 519 Lease liabilities 499 700 New jobs credit 8 8 Total long-term assets 51,602 41,031 Total deferred tax assets 51,602 41,031 U.S. federal and state deferred tax liabilities—long term: Right of use assets (432) (621) Total deferred tax liabilities (432) (621) Net deferred tax assets - long term 51,170 40,410 Less: Valuation allowance (51,170) (40,410) Net deferred tax assets $ — $ — Foreign deferred tax assets—long term: Net operating loss $ 8 $ 6 Total foreign deferred tax assets 8 6 Less: Valuation allowance (8) (6) Net deferred tax assets $ — $ —

SEGMENTS AND GEOGRAPHIC INFOR_2

SEGMENTS AND GEOGRAPHIC INFORMATION (Tables)	12 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Revenue from External Customers by Geographic Areas	The table below presents our revenue by geographic area (in thousands) and is categorized based on the location of the customer. 2021 2020 Japan $ 1,598 $ 2,716 China 289 406 Other 291 38 Total revenue $ 2,178 $ 3,160

ORGANIZATION AND DESCRIPTION _2

ORGANIZATION AND DESCRIPTION OF BUSINESS (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)patentsegment	Dec. 31, 2020USD ($)
Subsidiary, Sale of Stock [Line Items]
Number of operating segments | segment	1
Accumulated deficit	$ (186,876)	$ (150,906)
Net loss	(35,970)	(28,414)
Cash used	22,100
Cash and cash equivalents	$ 21,206	$ 24,968
IP Portfolio
Subsidiary, Sale of Stock [Line Items]
Number of developed technology patents | patent	415
IP Portfolio, XBAR Technology
Subsidiary, Sale of Stock [Line Items]
Number of developed technology patents | patent	265

SUMMARY OF SIGNIFICANT ACCOUN_3

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2021USD ($)financial_institution	Dec. 31, 2020USD ($)
Accounts Receivable
Allowance for doubtful accounts | $	$ 0	$ 0
Revenue Recognition
Contracted exclusivity period	2 years
Sales-based royalties, period in which payment is due	30 days
Minimum
Property, Plant and Equipment
Useful lives	2 years
Revenue Recognition
Amortization period	1 year
Maximum
Property, Plant and Equipment
Useful lives	5 years
Revenue Recognition
Amortization period	4 years
Letter of Credit
Restricted Cash
Letter of credit annual step down | $	$ 50	$ 50
United States
Concentration Risks, Types, No Concentration Percentage
Number of financial institutions	1
Switzerland | Subsidiaries
Concentration Risks, Types, No Concentration Percentage
Number of financial institutions	1
South Korea
Concentration Risks, Types, No Concentration Percentage
Number of financial institutions	1

REVENUE RECOGNITION - Narrative

REVENUE RECOGNITION - Narrative (Details) $ in Thousands	Sep. 30, 2021USD ($)specific_radio_frequencyinstallment	Sep. 29, 2020USD ($)	Oct. 11, 2019USD ($)	Sep. 30, 2019USD ($)specific_radio_frequency	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Nov. 10, 2021USD ($)	Oct. 31, 2021USD ($)	Dec. 31, 2019USD ($)
Disaggregation of Revenue [Line Items]
Contracted exclusivity period					2 years
Deferred revenue					$ 6,796	$ 1,783			$ 1,731
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Disaggregation of Revenue [Line Items]
Deferred revenue to be recognized					$ 6,800
Deferred revenue to be recognized, period					4 years
Proprietary Circuit Designs using XBAR Technology | Murata Manufacturing Co., Ltd.
Disaggregation of Revenue [Line Items]
Number of licensed radio frequencies or bands | specific_radio_frequency	4			4
Prepaid royalties				$ 9,000
Written termination period	30 days			30 days
Contracted exclusivity period				30 months
Revenue from collaboration agreement					$ 1,600	$ 2,700
Number of licensed radio frequencies or bands | specific_radio_frequency	4
Deferred revenue	$ 4,000				$ 4,500		$ 3,000
Number of installments | installment	2
Contract with customer, payment per band	$ 1,000
Band design period	3 years
Total transaction price								$ 7,000
Proprietary Circuit Designs using XBAR Technology | Murata Manufacturing Co., Ltd. | Accounts Receivable
Disaggregation of Revenue [Line Items]
Revenue from collaboration agreement		$ 2,500	$ 2,000
Minimum
Disaggregation of Revenue [Line Items]
Recognition period					1 year
Minimum | Proprietary Circuit Designs using XBAR Technology | Murata Manufacturing Co., Ltd.
Disaggregation of Revenue [Line Items]
Prepaid royalties	$ 8,000
Maximum
Disaggregation of Revenue [Line Items]
Recognition period					4 years
Maximum | Proprietary Circuit Designs using XBAR Technology | Murata Manufacturing Co., Ltd.
Disaggregation of Revenue [Line Items]
Prepaid royalties	$ 36,000

REVENUE RECOGNITION - Schedule

REVENUE RECOGNITION - Schedule of Changes in Contract Asset and Liability Balances (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Contract liabilities
Contract liabilities, beginning	$ 1,783	$ 1,731
Recognition of revenue included in beginning of year contract liabilities	(1,475)	(1,720)
Contract liabilities, net of revenue recognized on contracts during the period	6,688	1,772
Reversal of contract liabilities due to changes in transaction price	(200)	0
Contract liabilities, ending	$ 6,796	$ 1,783

PROPERTY AND EQUIPMENT, NET (De

PROPERTY AND EQUIPMENT, NET (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 5,420	$ 4,892
Less: Accumulated depreciation and amortization	(4,114)	(3,309)
Property and equipment, net	1,306	1,583
Depreciation	821	904
Assets disposed	16	233
Computers, peripheral and scientific equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,331	1,841
Software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	2,307	2,307
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	348	310
Office furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 434	$ 434

INTANGIBLE ASSETS, NET, AND G_3

INTANGIBLE ASSETS, NET, AND GOODWILL - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 3,022	$ 2,690
Write-off of abandoned patents	641	383
Amortization of intangible assets	79	96
Patents
Finite-Lived Intangible Assets [Line Items]
Intangible assets not subject to amortization	1,800
Patents
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 2,738	2,399
Patents | Minimum
Finite-Lived Intangible Assets [Line Items]
Useful life	11 years
Patents | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life	20 years
Other
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 284	$ 291
Useful life	10 years
STI | Patents
Finite-Lived Intangible Assets [Line Items]
Intangible assets, gross	$ 216
STI | Patents | Maximum
Finite-Lived Intangible Assets [Line Items]
Useful life	1 year

INTANGIBLE ASSETS, NET, AND G_4

INTANGIBLE ASSETS, NET, AND GOODWILL - Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets, Net [Abstract]
Intangible assets, gross	$ 3,022	$ 2,690
Less: Accumulated amortization	(383)	(571)
Total amortization expense	2,639	2,119
Impact of foreign currency translation	7	17
Patents
Finite-Lived Intangible Assets, Net [Abstract]
Intangible assets, gross	2,738	2,399
Other
Finite-Lived Intangible Assets, Net [Abstract]
Intangible assets, gross	$ 284	$ 291

INTANGIBLE ASSETS, NET, AND G_5

INTANGIBLE ASSETS, NET, AND GOODWILL - Schedule of Future Amortization Expense (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Total amortization expense	$ 2,639	$ 2,119
Intangible Assets, Excluding Pending Patents
Finite-Lived Intangible Assets [Line Items]
2022	53
2023	52
2024	50
2025	50
2026	50
2027 and thereafter	561
Total amortization expense	$ 816

INTANGIBLE ASSETS, NET, AND G_6

INTANGIBLE ASSETS, NET, AND GOODWILL - Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Goodwill [Roll Forward]
Balance at the beginning of the period	$ 911	$ 831
Effect of currency translation	(33)	80
Balance at the end of the period	$ 878	$ 911

WARRANTS - Narrative (Details)

WARRANTS - Narrative (Details)

Sep. 28, 2020shares

Jun. 17, 2020shares

Feb. 11, 2020shares

Sep. 28, 2017$ / sharesshares

Jun. 17, 2013$ / sharesshares

Aug. 31, 2020shares

Jun. 30, 2018shares

Oct. 31, 2017tranche$ / sharesshares

Dec. 31, 2021shares

Dec. 31, 2020shares

Nov. 30, 2017shares

Sep. 28, 2020

Dec. 31, 2019shares

Oct. 02, 2017shares

Warrant liabilities

Sales of common stock, net of offering costs (in shares)

201,000

Warrant

Warrant liabilities

Warrant exercised/expired (in shares)

2,134,362

Class of warrant or right, outstanding (in shares)

0

0

2,134,362

Placement Agents

Warrant liabilities

Period start after closing

6 months

Implied unit price/stock price (in dollars per share) | $ / shares

$ 4.85

Placement Agents | Private Placement, Offering One

Warrant liabilities

Sold in private placement (in shares)

87,279

Placement Agents | Private Placement, Offering Two

Warrant liabilities

Sold in private placement (in shares)

11,567

Consulting Warrant | Warrant

Warrant liabilities

Warrant exercised/expired (in shares)

6,667

Class of warrant or right, outstanding (in shares)

0

6,667

Consulting Warrant | MDB

Warrant liabilities

Warrant term

7 years

Warrants to purchase shares of common stock or units (in shares)

222,222

Exercise price (in dollars per share) | $ / shares

$ 0.01

Warrants exercisable period from underwriting agreement

6 months

Financing Warrant | Warrant

Warrant liabilities

Warrant exercised/expired (in shares)

62,530

Class of warrant or right, outstanding (in shares)

0

62,530

Financing Warrant | MDB

Warrant liabilities

Warrant term

7 years

Warrants to purchase shares of common stock or units (in shares)

208,763

Exercise price (in dollars per share) | $ / shares

$ 3.35

Warrants exercisable period from underwriting agreement

6 months

Warrant exercised/expired (in shares)

62,530

146,233

Private Placement Warrants, September 2017

Warrant liabilities

Warrant exercised/expired (in shares)

1,961,000

10,600

Cancellation of warrants (in shares)

5,319

Private Placement Warrants, September 2017 | Warrant

Warrant liabilities

Warrant exercised/expired (in shares)

1,966,319

Cancellation of warrants (in shares)

5,319

Class of warrant or right, outstanding (in shares)

0

1,966,319

Private Placement Warrants, September 2017 | Private Placement

Warrant liabilities

Warrants to purchase shares of common stock or units (in shares)

1,745,581

1,976,919

231,338

Class Of Warrant Or Right, Number Of Tranches | tranche

2

Period start after closing

6 months

Private Placement Warrants, September 2017 | Investors, Executives and Board Members | Capital Units

Warrant liabilities

Exercise price (in dollars per share) | $ / shares

$ 4.85

Private Placement Warrants, September 2017 | Investors, Executives and Board Members | Capital Units | Private Placement

Warrant liabilities

Sales of common stock, net of offering costs (in shares)

1,976,919

Underwriting Warrant

Warrant liabilities

Sales of common stock, net of offering costs (in shares)

1,976,919

Underwriting Warrant | Placement Agents

Warrant liabilities

Sales of common stock, net of offering costs (in shares)

98,846

WARRANTS - Schedule of Warrant

WARRANTS - Schedule of Warrant Activity (Details) - shares	Sep. 28, 2020	Aug. 31, 2020	Jun. 30, 2018	Dec. 31, 2020
Private Placement Warrants - September 2017
Roll forward of warrant activity
Warrant exercised/expired (in shares)	(1,961,000)		(10,600)
Cancellation of warrants (in shares)		5,319
Warrant
Roll forward of warrant activity
Balance at the beginning of the period (in shares)				2,134,362
Warrant exercised/expired (in shares)				(2,134,362)
Balance at the end of the period (in shares)				0
Warrant | Consulting Warrant
Roll forward of warrant activity
Balance at the beginning of the period (in shares)				6,667
Warrant exercised/expired (in shares)				(6,667)
Balance at the end of the period (in shares)				0
Exercise of warrants, cashless (in shares)				6,640
Warrant | Consulting Warrant | Cashless
Roll forward of warrant activity
Warrant exercised/expired (in shares)				(6,667)
Warrant | Financing Warrant
Roll forward of warrant activity
Balance at the beginning of the period (in shares)				62,530
Warrant exercised/expired (in shares)				(62,530)
Balance at the end of the period (in shares)				0
Expiration of warrants (in shares)				62,530
Warrant | Private Placement Warrants - September 2017
Roll forward of warrant activity
Balance at the beginning of the period (in shares)				1,966,319
Warrant exercised/expired (in shares)				(1,966,319)
Balance at the end of the period (in shares)				0
Expiration of warrants (in shares)				1,961,000
Cancellation of warrants (in shares)				5,319
Warrant | Placement Agent Warrants - 2017
Roll forward of warrant activity
Balance at the beginning of the period (in shares)				98,846
Warrant exercised/expired (in shares)				(98,846)
Balance at the end of the period (in shares)				0
Expiration of warrants (in shares)				98,846

STOCKHOLDERS_ EQUITY AND EARN_3

STOCKHOLDERS’ EQUITY AND EARNINGS PER SHARE (Details) $ / shares in Units, $ in Thousands	Feb. 11, 2020USD ($)shares	Feb. 10, 2020shares	Feb. 06, 2020$ / sharesshares	Dec. 31, 2021USD ($)vote$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	May 31, 2021USD ($)	Aug. 14, 2020USD ($)
Class of Stock [Line Items]
Common stock, shares authorized (in shares)				100,000,000	100,000,000
Number of votes | vote				1
Sales of common stock, net of offering costs (in shares)	201,000
Common stock, par value (in dollars per share) | $ / shares				$ 0.001	$ 0.001
Sales of common stock, net of offering costs | $	$ 28,800			$ 17,986	$ 37,447
Gross proceeds from the sale of common stock | $	$ 26,400			$ 18,614	$ 40,173
Preferred stock, shares authorized (in shares)				3,000,000	3,000,000
Preferred stock, shares issued (in shares)				0
Earnings Per Share [Abstract]
Shares excluded from computation of earnings per share (in shares)				4,371,704	4,179,760
Park City Capital
Class of Stock [Line Items]
Sales of common stock, net of offering costs (in shares)	134,000
Underwritten Public Offering
Class of Stock [Line Items]
Sales of common stock, net of offering costs (in shares)	19,166,667		16,666,667
Common stock, par value (in dollars per share) | $ / shares			$ 0.001
Share price (in dollars per share) | $ / shares			$ 1.50
Over-Allotment Option
Class of Stock [Line Items]
Sales of common stock, net of offering costs (in shares)	2,500,000
At-The-Market Equity Offering
Class of Stock [Line Items]
Share price (in dollars per share) | $ / shares				$ 3.33	$ 2.48
Gross proceeds from the sale of common stock | $				$ 18,100	$ 11,000
Remaining authorized amount to be sold | $							$ 25,000
Sale of stock, authorized amount | $						$ 50,000
Sales of common stock (in shares)				5,592,570	4,609,701
Sale of common stock, net of offering costs | $				$ 18,600	$ 11,400
Common Stock
Earnings Per Share [Abstract]
Shares excluded from computation of earnings per share (in shares)				945,076	1,140,975
Common Stock | Over-Allotment Option
Class of Stock [Line Items]
Sales of common stock, net of offering costs (in shares)		2,500,000
Option to purchase period		30 days
Non-vested restricted stock units
Earnings Per Share [Abstract]
Shares excluded from computation of earnings per share (in shares)				3,426,628	3,038,785

STOCK-BASED COMPENSATION - Narr

STOCK-BASED COMPENSATION - Narrative (Details)	Sep. 30, 2022USD ($)	Jun. 30, 2020shares	Dec. 31, 2019USD ($)$ / sharesshares	Jun. 30, 2019shares	Jun. 30, 2017shares	Aug. 31, 2016$ / sharesshares	Jun. 30, 2016shares	Dec. 31, 2021USD ($)quarter$ / sharesshares	Dec. 31, 2020USD ($)$ / sharesshares	Jan. 31, 2014shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant date fair value								$ 20,000	$ 177,000
Nonvested stock options (in shares) | shares								95,866	185,673
Unrecognized compensation expense related to unvested employee stock option								$ 8,600,000
Options outstanding, aggregate intrinsic value								374,000	$ 170,000
Expense, tax benefit								0	0
Total fair value vested								7,600,000	6,200,000
Sales, Marketing and Administration
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense								$ 42,000	$ 42,000
Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair value (in dollars per share) | $ / shares									$ 1.68
Common Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of quarter over which awards vest from grant date subsequent to initial vesting | quarter								16
Stock compensation expense								$ 166,000	$ 236,000
Weighted average grant date fair value of nonvested stock options (in dollars per share) | $ / shares								$ 2.03	$ 2.05
Weighted average grant date fair value (in dollars per share) | $ / shares								$ 4.04
Unrecognized compensation expense related to unvested employee stock option								$ 162,000
Weighted average period								1 year 9 months 18 days
Options outstanding, aggregate intrinsic value								$ 0
Share price (in dollars per share) | $ / shares								$ 5.31
Options vested, aggregate intrinsic value									$ 130,000
Common Stock Options | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in dollars per share) | $ / shares								$ 1.71	$ 2.65
Common Stock Options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in dollars per share) | $ / shares									1.74
Common Stock Options | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in dollars per share) | $ / shares									$ 2.85
Common Stock Options | Employees and Consultants
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Term of award								10 years
Common Stock Options | Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forfeitures rate									10.00%
Non-vested restricted stock units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense								$ 7,800,000	$ 5,500,000
Weighted average period								2 years 1 month 6 days
Granted (in shares) | shares								2,851,443	3,091,206
Non-vested restricted stock units | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period								3 years
Non-vested restricted stock units | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period								4 years
Non-vested restricted stock units | Employees | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period								10 days
Performance Based Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period								9 months	9 months
Compensation cost not yet recognized								$ 31,500
Performance Based Awards | Executive Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in dollars per share) | $ / shares			$ 2.15			$ 5.06		$ 2.73
Granted (in shares) | shares			200,000	500,000		250,000
Award vesting rights, percentage								50.00%
Performance Based Awards | Executive Employees | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting rights, percentage								50.00%
Incentive Bonus Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Accrued bonuses								$ 0	$ 0
2014 Omnibus Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares of common stock approved for issuance (in shares) | shares								14,950,000		1,400,000
Number of additional shares authorized (in shares) | shares		5,000,000		4,000,000	3,250,000		1,300,000
Number of shares available to issue (in shares) | shares								3,259,944
2015 Performance Plan | Performance Based Awards | Research and Development
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation expense								$ 9,000	$ 9,000
2015 Performance Plan | Performance Based Awards | Executive Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation cost not yet recognized			$ 6,500
2015 Performance Plan | Performance Based Awards | Executive Employees | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of award			$ 26,000					$ 74,000
2015 Performance Plan | Performance Based Awards | Executive Employees | Common Stock | Forecast
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Fair value of award	$ 147,000

STOCK-BASED COMPENSATION - Esti

STOCK-BASED COMPENSATION - Estimated Fair Value of Stock Options (Details) - Common Stock Options - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in dollars per share)	$ 5.31
Dividend Yield	0.00%	0.00%
Expected Term	7 years	7 years
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in dollars per share)		$ 1.74
Expected Volatility	88.00%	70.00%
Risk-free interest rate	0.72%	0.36%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share price (in dollars per share)		$ 2.85
Expected Volatility		83.00%
Risk-free interest rate		1.52%

STOCK-BASED COMPENSATION - Stoc

STOCK-BASED COMPENSATION - Stock Option Award Activity (Details) - Common Stock Options - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Number of Options
Outstanding at the beginning of the year (in shares)	1,140,975
Granted (in shares)	5,000
Exercised (in shares)	(105,098)
Canceled/Forfeited (in shares)	(95,801)
Outstanding at the end of the reporting period (in shares)	945,076	1,140,975
Number of Options Exercisable
Exercisable at the beginning of the year (in shares)	955,302
Vested (in shares)	74,198
Exercised (in shares)	(105,098)
Canceled/Forfeited (in shares)	(75,192)
Exercisable at the end of the reporting period (in shares)	849,210	955,302
Weighted Average Exercise Price
Outstanding at the beginning of period (in dollars per share)	$ 4.46
Granted (in dollars per share)	5.31
Exercised (in dollars per share)	2.79
Forfeited (in dollars per share)	4.90
Outstanding at the end of the reporting period (in dollars per share)	4.60	$ 4.46
Weighted Average Exercise Price Exercisable
Exercisable at the beginning of the reporting period (in dollars per share)	4.74
Vested exercisable (in dollars per share)	3.44
Exercised (in dollars per share)	2.79
Canceled/Forfeited (in dollars per share)	5.55
Exercisable at the end of the reporting period (in dollars per share)	4.79	4.74
Weighted Average Grant Date Fair Value
Outstanding at the beginning of the reporting period (in dollars per share)	2.81
Options granted (in dollars per share)	4.04
Exercised (in dollars per share)	1.69
Forfeited (in dollars per share)	3.02
Outstanding at the end of the reporting period (in dollars per share)	2.92	2.81
Weighted Average Grant Date Fair Value Exercisable
Exercisable at the beginning of the reporting period (in dollars per share)	2.96
Vested options exercisable (in dollars per share)	2.32
Exercised (in dollars per share)	1.69
Forfeited options exercisable (in dollars per share)	3.35
Exercisable at the end of the reporting period (in dollars per share)	$ 3.02	$ 2.96
Weighted Average Remaining Life In Years
Outstanding, Weighted average remaining life (in years)	4 years 8 months 4 days	5 years 8 months 8 days
Granted, Weighted average remaining life (in years)	9 years 14 days
Weighted Average Remaining Life Exercisable
Outstanding, Weighted average remaining contractual term (in years)	4 years 3 months 25 days	5 years 1 month 6 days
Vested, Weighted average remaining live (in years)	6 years 7 months 28 days

STOCK-BASED COMPENSATION - Rest

STOCK-BASED COMPENSATION - Restricted Stock Activity (Details) - Non-vested restricted stock units - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Restricted Share Units
Outstanding at beginning of year (in shares)	3,038,785	2,556,004
Granted (in shares)	2,851,443	3,091,206
Vested (in shares)	(2,173,829)	(2,183,163)
Forfeited (in shares)	(289,771)	(425,262)
Outstanding at end of year (in shares)	3,426,628	3,038,785
Restricted Share Weighted Average Grant Date Fair Value
Outstanding at beginning of year (in dollars per share)	$ 2.53	$ 3.38
Granted (in dollars per share)	4.38	2.04
Vested (in dollars per share)	3.51	2.82
Forfeited (in dollars per share)	3.88	2.57
Outstanding at end of year (in dollars per share)	$ 3.44	$ 2.53

STOCK-BASED COMPENSATION - Equi

STOCK-BASED COMPENSATION - Equity Based Compensation Schedule (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Allocation of stock-based compensation expense
Stock compensation expense	$ 7,954	$ 5,824
Research and development
Allocation of stock-based compensation expense
Stock compensation expense	3,779	2,753
Sales, marketing and administration
Allocation of stock-based compensation expense
Stock compensation expense	$ 4,175	$ 3,071

LEASES - Narrative (Details)

LEASES - Narrative (Details)	May 01, 2020USD ($)lease	Dec. 31, 2021USD ($)leaserenewal_option	Dec. 31, 2020USD ($)	Oct. 06, 2021USD ($)ft²
Lessee, Lease, Description [Line Items]
Number of operating lease | lease		2
Number of non-cancelable leases | lease		2
Restricted cash		$ 55,000	$ 0
Number of renewal options recognized | renewal_option		0
Finance lease liability		$ 175,000
Operating lease cost		1,219,000	1,132,000
Cash paid for operating lease liabilities		777,000	613,000
Finance lease right-of-use asset amortization		41,000	0
Research and Development Expense
Lessee, Lease, Description [Line Items]
Operating lease cost		804,000	812,000
Finance lease right-of-use asset amortization		41,000	3,000
Selling, General and Administrative Expenses
Lessee, Lease, Description [Line Items]
Operating lease cost		$ 415,000	320,000
Sublease Agreement | Sonim Technologies, Inc.
Lessee, Lease, Description [Line Items]
Area of property | ft²				8,416
Initial, monthly rent				$ 12,500
Renewal term				1 year
Renewal, monthly rent				$ 13,250
Lease Amendment
Lessee, Lease, Description [Line Items]
Operating lease renewal periods	3 months
Number of leases amended | lease	1
Base rent deferral period	3 months
Operating expense deferral period		3 months
Lab Equipment Lease
Lessee, Lease, Description [Line Items]
Finance lease term		60 months
Finance lease interest rate		5.99%
Finance lease, right-of-use asset		$ 204,000
Finance lease liability		204,000
Office Building | Letter of Credit
Lessee, Lease, Description [Line Items]
Security deposit		$ 50,000
Operating lease deposit, letter of credit	$ 200,000
Line of credit facility, annual step down of no defaults			$ 50,000
Minimum | Facilities
Lessee, Lease, Description [Line Items]
Operating lease renewal periods		2 years
Maximum | Facilities
Lessee, Lease, Description [Line Items]
Operating lease renewal periods		5 years
Maximum | Facilities and Equipment
Lessee, Lease, Description [Line Items]
Operating lease term		12 months

LEASES - Weighted-Average Remai

LEASES - Weighted-Average Remaining Lease Term (Details)	Dec. 31, 2021
Weighted average remaining lease term (years)
Operating leases	2 years 10 months 17 days
Finance lease	3 years 11 months 1 day
Weighted average discount rate (%)
Operating leases	4.75%
Finance lease	5.99%

LEASES - Maturities of Operatin

LEASES - Maturities of Operating and Financing Lease Liabilities (Details) $ in Thousands	Dec. 31, 2021USD ($)
Operating Leases
2022	$ 586
2023	584
2024	544
2025	0
Total minimum lease payments	1,714
Less: interest	(111)
Present value of minimum lease payments	1,603
Finance Lease
2022	50
2023	50
2024	50
2025	46
Total minimum lease payments	196
Less: interest	(21)
Present value of minimum lease payments	$ 175

INCOME TAXES - Income Taxes by

INCOME TAXES - Income Taxes by Jurisdiction (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
U.S. federal:
Current	$ 0	$ 0
Deferred	0	0
Total U.S. federal	0	0
U.S. state and local:
Current	1	1
Deferred	0	0
Total U.S. state and local	1	1
Foreign:
Current	0	0
Deferred	0	0
Total foreign	0	0
Provision for (benefit from) income taxes	1	1
Income taxes differ from the amounts computed by applying the U.S. federal income tax rate to pretax income (loss) before income taxes
Expected income tax benefit	(7,554)	(5,966)
State income tax (benefit), net of federal benefit	(2,812)	(1,961)
Valuation allowance	10,761	7,732
Permanent differences:
Stock options	255	353
Research & development credit	(617)	(560)
Adjustment to deferred taxes	(55)	400
Foreign rate differential	1	(1)
Other	22	4
Provision for (benefit from) income taxes	$ 1	$ 1

INCOME TAXES - Narrative (Detai

INCOME TAXES - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Operating Loss Carryforwards [Line Items]
Provision for income taxes	$ 1	$ 1
Increase of valuation allowance	10,800	7,700
Federal net operating loss carryforwards	159,400
State net operating loss carryforwards	162,100
Tax cuts and jobs act of 2017, federal net operating loss carryforwards	$ 112,500
Percentage of tax cuts and jobs act of 2017, federal net operating loss carryforwards	80.00%
Operating loss carryforwards that will expire	$ 0
Interest
Penalties	0	0
Unrecognized tax benefits	0	0
Significant uncertain tax positions	1,200	$ 1,000
Switzerland
Operating Loss Carryforwards [Line Items]
Foreign net operating loss carryforwards	$ 52

INCOME TAXES - Deferred Tax Ass

INCOME TAXES - Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
U.S. Federal and State
U.S. federal and state deferred tax assets—long term:
Accrued payroll	$ 200	$ 180
Accrued expenses	54	53
Fixed assets	36	17
Charitable contributions	28	14
Intangibles	473	431
Research & development credit	4,874	3,830
Net operating loss	44,772	35,279
Stock compensation	658	519
Lease liabilities	499	700
New jobs credit	8	8
Total deferred tax assets	51,602	41,031
U.S. federal and state deferred tax liabilities—long term:
Right of use assets	(432)	(621)
Total deferred tax liabilities	(432)	(621)
Total long-term assets	51,170	40,410
Less: Valuation allowance	(51,170)	(40,410)
Net deferred tax assets	0	0
Foreign
U.S. federal and state deferred tax assets—long term:
Net operating loss	8	6
U.S. federal and state deferred tax liabilities—long term:
Total long-term assets	8	6
Less: Valuation allowance	(8)	(6)
Net deferred tax assets	$ 0	$ 0

COMMITMENTS AND CONTINGENCIES (

COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Purchase commitment amount	$ 0.7
Loss contingency accrual	0	$ 0
Loss in period	$ 0	$ 0

RELATED PARTY TRANSACTIONS (Det

RELATED PARTY TRANSACTIONS (Details)	1 Months Ended	12 Months Ended
	Aug. 31, 2019USD ($)installment	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Oct. 06, 2021USD ($)ft²
Consulting Agreement
Related Party Transactions
Amount of transaction	$ 50,000
Number of installments | installment	12
Expenses from transaction with related party		$ 50,000	$ 50,000
Consulting Agreement | Director
Related Party Transactions
Due to related parties		4,000
Consulting Agreement | Research and Development Expense
Related Party Transactions
Stock issued during period, value, restricted stock award, gross		100,000	$ 102,000
Consulting Agreement | Non-vested restricted stock units
Related Party Transactions
Expenses from transaction with related party	$ 100,000	$ 100,000
Sublease Agreement | Sonim Technologies, Inc.
Related Party Transactions
Area of property | ft²				8,416
Initial, monthly rent				$ 12,500
Renewal term				1 year
Renewal, monthly rent				$ 13,250

EMPLOYEE BENEFIT PLAN (Details)

EMPLOYEE BENEFIT PLAN (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
401(k) Savings Retirement Plan
Defined Contribution Plan Disclosure [Line Items]
Recorded plan matching contributions	$ 524	$ 494

SEGMENTS AND GEOGRAPHIC INFOR_3

SEGMENTS AND GEOGRAPHIC INFORMATION (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
REVENUES	$ 2,178	$ 3,160
Japan
Segment Reporting Information [Line Items]
REVENUES	1,598	2,716
China
Segment Reporting Information [Line Items]
REVENUES	289	406
Other
Segment Reporting Information [Line Items]
REVENUES	$ 291	$ 38

SUBSEQUENT EVENTS (Details)

SUBSEQUENT EVENTS (Details) - USD ($) $ / shares in Units, $ in Millions	Feb. 14, 2022	Dec. 31, 2021	Dec. 31, 2020
Subsequent Event [Line Items]
Common stock, par value (in dollars per share)		$ 0.001	$ 0.001
Subsequent Event | Merger Agreement
Subsequent Event [Line Items]
Termination fee	$ 11.2
Subsequent Event | Merger Agreement | Maximum
Subsequent Event [Line Items]
Reimburse expense	$ 3
Subsequent Event | Merger Agreement | Murata
Subsequent Event [Line Items]
Common stock, par value (in dollars per share)	$ 0.001
Purchase price (in dollars per share)	$ 4.50
Number of shares issued and outstanding	50.00%
Termination fee	$ 15