The BDC-040180-20 from Atlantic Microwave is a Directional Coupler with Frequency 4 to 18 GHz, Coupling 20 dB, Coupling Variation ± 1 dB, Frequency Sensitivity ±1 dB, Directivity 12 dB. Tags: Module with Connectors. More details for BDC-040180-20 can be seen below.