CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Cost of revenue	$ 9,705	$ 8,111	$ 18,025	$ 16,543
Gross profit	11,798	10,098	22,089	19,170
Operating expenses:
Research and development	15,618	14,417	31,428	27,857
Selling, general and administrative	16,112	16,740	32,025	32,901
Total operating expenses	31,730	31,157	63,453	60,758
Loss from operations	(14,608)	(16,793)	(30,010)	(32,861)
Non-operating expense, net:
Foreign exchange gain (loss)	273	105	50	(57)
Interest expense	(929)	(1,150)	(1,864)	(4,074)
Other income, net	460	337	611	759
Total non-operating expense, net	(196)	(708)	(1,203)	(3,372)
Loss before income taxes	(14,804)	(17,501)	(31,213)	(36,233)
Provision for income taxes	67	61	124	121
Net loss	$ (14,871)	$ (17,562)	$ (31,337)	$ (36,354)
Net loss per share:
Basic and diluted	$ (0.09)	$ (0.13)	$ (0.19)	$ (0.26)
Weighted average shares used for calculating net loss per share:
Basic and diluted	164,383	138,281	160,894	137,698
Product
Revenue	$ 21,503	$ 18,209	$ 40,114	$ 35,713
Government Contract
Revenue	$ 5,324	$ 4,266	$ 11,354	$ 8,727