A millimeter-wave pumped X-band uncooled parametric amplifier

GaAs Schottky barrier varactors with a cutoff frequency of 800 GHz have been used in a balanced diode type of parametric amplifier operating with a signal frequency at 7.5 GHz. The parameters of the overall amplifier operating at room temperature are a gain of 15 dB, a bandwidth of 500 MHz, and an excess noise temperature of 63 K (a noise figure of 0.86 dB).