Operation of avalanche diodes as c.w. amplifiers at fractions of the transit frequency

The operation of an avalanche diode as a self-pumped parametric amplifier at low current densities is described. Gains of up to 15 dB are obtained at frequencies of the order of one-quarter of the transit frequency, while the diode is providing its own pump at three-quarters of that frequency. A theory based on utilising a Read-diode approximation to the device is used to calculate the response of such an amplifier, and good agreement is found for both the gain and saturation characteristics of the device.