CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Cost of revenue	$ 15,323	$ 9,705	$ 26,418	$ 18,025
Gross profit	16,161	11,798	28,445	22,089
Operating expenses:
Research and development	17,083	15,618	32,831	31,428
Selling, general and administrative	19,758	16,112	38,928	32,025
Total operating expenses	36,841	31,730	71,759	63,453
Loss from operations	(14,401)	(14,608)	(30,848)	(30,010)
Non-operating expense, net:
Foreign exchange gain (loss)	118	273	(278)	50
Interest expense	(1,338)	(929)	(2,310)	(1,864)
Other income, net	337	460	793	611
Total non-operating expense, net	(883)	(196)	(1,795)	(1,203)
Loss before income taxes	(15,284)	(14,804)	(32,643)	(31,213)
Provision for income taxes	77	67	175	124
Net loss	$ (15,361)	$ (14,871)	$ (32,818)	$ (31,337)
Net loss per share:
Basic and diluted	$ (0.09)	$ (0.09)	$ (0.19)	$ (0.19)
Weighted average shares used for calculating net loss per share:
Basic and diluted	171,240	164,383	170,039	160,894
Product
Revenue	$ 31,484	$ 21,503	$ 54,863	$ 40,114
Government Contract
Revenue	$ 6,279	$ 5,324	$ 12,466	$ 11,354