MIMO imaging radar with enhanced range-azimuth sidelobe suppression

This paper focuses on the suppression of range and azimuth sidelobe of multiple-input and multiple-output (MIMO) imaging radars by means of a generation of highly-orthogonal waveforms and the implementation of the adaptive beamforming. High orthogonality of waveforms is obtained by transmitting multiple sets of Gold codes, which are generated by varying the initial value of a register at each pulse repetition. Using 255 sets of Gold code of length 255, more than 65 dB peak-to-sidelobe level for a stationary target and approximately 40 dB for a moving target are respectively achieved. The adaptive beamformer is implemented to suppress the azimuth sidelobe caused by the array calibration error. Simulation results have shown MIMO radar antenna configuration of 8 transmitters and 16 receivers achieves approximately 45 dB peak-to-sidelobe level under the presence of the calibration error of −25 dB.