The C-0420-30 from ET Industries is a Stripline Directional Coupler that operates from 0.4 to 20 GHz. This 30 dB coupler has more than 14 dB of directivity and an insertion loss of less than 0.7 dB. The coupler can handle an average input power of 20 W and a peak input power of 3 kW. It is available in a module that measures 4.4 x 0.7 x 0.5 inches and has SMA-female connectors.
