Parametric Amplifier

An item, the output characteristics of which are uniformly related to the input signal, but of greater amplitude with respect to current and/or voltage. It consists basically of an input signal inductance, an output signal inductance, and a semiconductor diode device. An external source of radio frequency power, commonly referred to as the "pump frequency" is injected across the diode at a frequency fundamentally or harmonically related to the input signal frequency. The diode, operating as a type of frequency-controlled capacitor, increases the amplitude of the input signal by an appreciable value, at an almost zero noise level. The characteristic of extremely low noise level at very high operating frequencies, makes the amplifier suitable for use with radar receivers, missile detection and tracking equipments, radio astronomy research, and the like. Excludes amplifier, radio frequency.