High-efficiency operation of transferred-electron devices in the hybrid mode

Efficiencies up to 22% at peak-power levels of 60 W in X band have been obtained with transferred-electron devices. These efficiencies are in good agreement with values computed from hybrid-mode theory. A waveguide circuit which permits independent adjustment of the resistive and reactive components of the circuit impedance at the device-package terminals is described. This circuit provides a match for devices with widely different impedances. The close agreement between the theoretical and experimental values of efficiency indicate that both high material quality and an optimum impedance match between the device and the circuit have been achieved.