Sidelobe Suppression of Scanning Synthetic Beams Based on Coincidence Imaging Array Radar

Low sidelobe levels (SLLs) in scanning synthetic beams remain a problem for coincidence imaging array radar (CIAR) to achieve excellent anti-interference performance. In this communication, a sidelobe suppression method for the scanning synthetic beams is proposed. First, the fundamental model of the synthetic beam scanning method is presented with the introduction of the directional matching filter. Subsequently, the covariance matrix of the excitation signals is optimized using a convex optimization algorithm. This optimization allows for uniform bunching of the average power pattern within a specific angle range and simultaneous sidelobes' suppression of the scanning synthetic patterns. In addition to the partially correlated excitation signals without practical constraints, the excitation signals are synthesized using the alternating minimization algorithm when considering a constant modulus constraint. Finally, numerical simulations and experiments are conducted to validate the proposed sidelobe suppression method. The results demonstrate that the SLLs of the synthetic patterns with varying steering angles can be reduced to below -19.5 dB.