A Comparison of One- and Two-Idler Parametric Amplifiers (Correspondence)

The performance of a two-idler parametric amplifer is compared with that of a single-idler amplifer with a broad-banding resonator at its input. Both circuits contain the same varactor and are pumped at the same frequency. For most of the cases considered the two-idler amplifier gives a somewhat narrower bandwidth, slightly higher noise temperature, but lower sensitivity to variation of m₁ (the pump modulation rate) than the single-idler amplifier. The comparison is made over a range of pump and varactor cutoff frequencies