Characterizing the Impact of IQ Imbalance and DC Bias on Pulse-Agile Radar Processing

Abstract

The advent of commercial-off-the-shelf (COTS) software-defined radars (SDRs) has enabled low-cost, flexible experimentation with emerging pulse-agile waveform designs to mitigate spectral congestion, improve radar performance, embed communications, and other applications. We examine the impact of direct digital downconversion sampling imperfections in the form of IQ imbalance and DC bias on pulse-agile waveforms. A general framework is developed and examples given for a particular radar-embedded communication waveform. It is shown that the clutter response due to IQ imbalance is significantly increased in a pulse agile framework.