PARAMETRIC AMPLIFIER (PARAMP)

An amplifier that (a) has a very low noise level , (b) has a main oscillator that is tuned to the received frequency , (c) has another pumping oscillator of a different frequency that periodically varies the parameters, i.e., the capacitance or inductance, of the main oscillator circuit , and (d) enables amplification of the applied signal by making use of the energy from the pumping action. Note: Paramps with a variable-capacitance main-oscillator semiconductor diode are used in radar tracking and communications Earth stations, Earth satellite stations, and deep-space stations. The noise temperature of paramps cooled to the temperature of liquid helium, about 5 K, is in the range of 20 to 30 K. Paramp gains are about 40 dB . [ From Weik '89 ]