Azimuth Sidelobe Suppression Method for Through-the-Wall Radar Based on Phase Nonuniform Quantized Coherence Factor

In through-the-wall radar systems, sparse arrays are frequently utilized to optimize the trade-off between system cost and array aperture. Nevertheless, the radar image will suffer from high azimuth sidelobes, resulting in fake targets in detection. To solve this problem, an azimuth sidelobe suppression method for through-the-wall radar based on phase nonuniform quantized coherence factor is proposed in this paper. Firstly, based on the positional relationship among the transceivers, target, and imaging grid, the phase at the azimuth sidelobe position in radar image can be determined, which is only relevant to radar parameters. Secondly, the quantized intervals are divided by the calculated phase. Additionally, the phase at each imaging grid is quantized to guarantee the maximum phase difference at the azimuth sidelobe position. Ultimately, the weight image is computed using the phase standard deviation. By applying weights to the original radar image, the azimuth sidelobes are effectively suppressed. Both numerical simulations and experimental results are analyzed to demonstrate the superiority and robustness of the proposed method.