Millimeter-wave sideband generation using varactor phase modulators

A sideband generator based on phase modulation is presented. The sideband generator consists of a Schottky varactor diode mounted in a WR-10 waveguide tuned resonant circuit. A microwave pump signal modulates the phase of the reflection coefficient the circuit presents to an incident millimeter-wave signal. This proof-of-principle circuit has shown a sideband conversion loss of 9 dB and bandwidth of nearly 10% at 80 GHz. These results represent significant improvements over the performance of sideband generators based on resistive mixing in corner-cube mounts.