On the Impact of Channel Imbalance on MIMO Radar Performance

The multiple-input multiple-output (MIMO) radar systems suffer from several types of system imperfections such as antenna mutual coupling, channel imbalance, system hardware limitations, and noise. Through calibration the deterministic system imperfections can be significantly reduced. Some sources of system degradation are time-variant and require re-calibration for instance amplitude and phase drift, while other sources are random, which makes calibration unfeasible. The effects of such sources are analysed with a MIMO radar model using time-division multiplexed (TDM) frequency modulated waveforms. The direction-of-arrival (DOA) estimation error based on a discrete Fourier transform (DFT) together with the peak sidelobe level (PSL) are used as performance parameters.