Microwave characterization of a resistive-gate MESFET oscillator

Measurements of microwave oscillations in resistive-gate MESFET contiguous-domain oscillator devices are discussed. Oscillation frequencies in the ranges from 22 to 30 GHz and 37 to 42 GHz are observed independently of the device length, and frequency can be tuned during operation by varying the source-to-gate voltage. Evidence suggests that the observed signals are harmonics of a fundamental signal in the range from 11 to 15 GHz. While the possibility that conventional transit-time Gunn domain propagation is occurring in this frequency range cannot be ruled out, the fact that frequency is independent of channel length suggests that contiguous domains are forming, at least in the longer devices. Because of its structure, the resistive-gate MESFET oscillator can be easily incorporated into MESFET integrated circuits for MMIC (monolithic microwave integrated circuit) applications.<>