The DC 16-DQB-(***-***)-B-(**) from The Waveguide Solution is a Waveguide Coupler with Frequency 8.2 to 12.4 GHz, Coupling 10 dB, 20 dB, 30 dB, Directivity 40 dB. Tags: Broadwall Coupler. More details for DC 16-DQB-(***-***)-B-(**) can be seen below.