Product Line, Customer and Geographic Information - Result of Product Line Revenues and Gross Profits (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Results of operations by segments
Revenues	$ 87,807	$ 77,456
Gross Profit	$ 40,478	$ 37,927
Gross Profit %	46.10%	49.00%
Operating Segments [Member] | Antennas & Industrial IoT Devices [Member]
Results of operations by segments
Revenues	$ 63,025	$ 50,540
Gross Profit	$ 21,031	$ 17,665
Gross Profit %	33.40%	35.00%
Operating Segments [Member] | Test & Measurement Products [Member]
Results of operations by segments
Revenues	$ 25,704	$ 27,565
Gross Profit	$ 19,592	$ 20,244
Gross Profit %	76.20%	73.40%
Corporate, Non-Segment [Member]
Results of operations by segments
Revenues	$ (922)	$ (649)
Gross Profit	$ (145)	$ 18