Abstract

The Mechanism of the generation of microwave and millimeter wave oscillations by an n-type GaAs bulk effect oscillator is investigated. A Simplified model of domain dynamics within the sample is developed. Based on this model, the microwave performance of a bulk effect device is evaluated, as a function of carrier concentration, sample bias voltage an sample length. The graphical analysis resulting from the model indicates a dynamic velocity-field characteristic which differs from the static velocity-field characteristic. The model is employed to indicate the possibility of a variety of modes of operation of a given device, including a mode of domain suppression which allows frequencies to be generated which greatly exceed the Gunn transit time frequency. Finally, experimental results are presented which correlate and verify the theoretically indicated distinct modes of operation of given bulk effect device. These modes of oscillation are semi-quantitatively discussed, in terms of the results of the simplified model of domain dynamics.