Active element microwave phase shifter

摘要

A continuously variable phase shifter for the phase range from 0 DEG to 90 DEG , switchable phase shifters switchable between 0 DEG and 90 DEG and a continuously variable phase shifter for the phase shift range of 0 DEG to 360 DEG are disclosed. Each of the phase shifters relies on dual gate FET devices to provide the required phase shift in a compact structure while providing sufficient gain to avoid signal losses through the phase shifter. The transmission phase shift through a dual gate FET device is controlled by the DC bias on its second gate and by the type of reactive termination on that gate. A capacitive termination provides a transmission phase shift which is substantially independent of bias while an inductive termination provides a transmission phase shift which varies substantially linearly with bias voltage over a substantial range of bias voltage.