Pulsed GaAs oscillators

This paper will present the latest developments in pulsed oscillators which utilize the Gunn effect in gallium arsenide for the generation of microwave power. General engineering design criteria are being developed relating power, frequency, impedance level, device and circuit efficency, circuit and voltage tuning, and thermal parameters. It will be shown that ultimate pulsed powers should be proportional to (frequency)^-2, as in tubes. Average powers should be more nearly constant from L to X-band. Power capability depends critically on properties of the gallium arsenide material. Examples will be given using currently available material, and also assuming the existence of "perfect" GaAs. Pulsed oscillators will be described which deliver over 100 watts at L-band. The best performance to date has been 190 watts at 1100 mc., using two samples in parallel. Techniques for achieving this type of operation will be described.