Gunn-effect oscillators for the 40-60 giga-hertz range

Gunn-effect oscillators have been developed for operation in the 40-60- GHz range. The diodes are in hermetically sealed, low-reactance packages and the oscillators operate stably over a Wide temperature range. Rectangular waveguide resonators are used with iris coupling to the output waveguide. A sapphire tuning rod. tunes the oscillator over a bandwidth of several percent. The diodes, with threshold voltages in the 1.2- to 1.8-volt range, are operated in the transit-time mode, and are made from solution-grown epitaxial gallium arsenide with a doping of around 5 × 10¹⁵carriers per cm³.