The MM-BDC-180400-20 from Mountain Microwave Technology is a Directional Coupler with Frequency 18 to 40 GHz, Coupling 20 dB, Coupling Variation ±1.0 dB, Directivity 12 dB, Average Power 20 W. Tags: Module with Connectors. More details for MM-BDC-180400-20 can be seen below.