The CE20-0R640 from Marki Microwave is a Directional Coupler with Frequency 0.6 to 40 GHz, Coupling 19.5 to 20.5 dB, Coupling Variation ±1 to ±2 dB, Amplitude Flatness ±0.15 to ±0.40 dB, Directivity 15 to 27 dB. Tags: Module with Connectors. More details for CE20-0R640 can be seen below.