Abstract: A microwave frequency discriminator including a multi-stage limiter-amplifier and a detector in an environment of a wide band RF signal of varying power level. The limiter-amplifier comprises a plurality of cascaded saturated amplifiers including an unsaturated output-stage amplifier. The response of the unsaturated output stage amplifier is such that the RF power varies substantially linearly with the input frequency over a predetermined bandwidth. The detector converts the RF signal to a linear dc signal.

Abstract: An improved frequency memory system of the type using a voltage controlled oscillator is described. Incoming RF signals are power divided with a first power divided portion applied to a frequency discriminator where a voltage level signal indicative of frequency is derived. This voltage level signal is shaped and applied to the volage controlled oscillator wherein the oscillator is broadly tuned to the incoming frequency. A remaining portion of the power divided signal is applied directly to the RF circuit portion of the VCO oscillator to injection lock the VCO oscillator to the incoming signal.

Abstract: A microwave frequency discriminator comprising a field effect transistor (FET) amplifier, input and output impedance matching networks and a detector. The FET is biased to generate an output RF signal within a predetermined frequency bandwidth in response to an input RF signal of substantially constant power level. The input and output impedance matching networks are arranged to provide the impedance conditions to shape and linearize the power-frequency response of the FET amplifier throughout the predetermined frequency bandwidth such that the frequency response approximates the linear power-frequency characteristic of a frequency discriminator.

Abstract: Two transferred electron devices are provided in a thermally coupled relationship. One transferred electron device is operated above threshold voltage as an amplifier or oscillator, while the other transferred electron device is operated below threshold voltage so as to supply heat to the first device, to compensate for any operating temperature changes and thereby maintain the first device at a substantially constant temperature.