Signal Fidelity in Degenerate and Nondegenerate Mode Parametric Amplifier Receiving Antennas

The gain, received power bandwidth, transient characteristics, and signal fidelity of two time-varying electrically small receiving antennas based on parametric amplifier design are studied using practical quadrature amplitude modulation (QAM) signals. Results show that interference from the difference harmonic present in the response of degenerate-mode parametric amplification decreases its signal throughput relative to a reference linear time-invariant (LTI) receiver, despite its apparent increased received power bandwidth in the frequency domain. The analysis also demonstrates that a nondegenerate parametric receiver, lacking this detrimental effect, exhibits increased signal throughput over the reference LTI receiver.