A Novel Weighted Mismatched Filter for Reducing Range Sidelobes

Abstract

Pulse compression, usually achieved using a matched filter, is extensively applied in radar/sonar systems. This process improves the signal-to-noise ratio (SNR) of the received signal without increasing the peak transmitted power. However, it is often desirable to accept a slight penalty in the target SNR in order to suppress the range sidelobes. In this paper, a novel weighted mismatched filter (WMMF) that can reduce range sidelobes to the designed level over specified regions is proposed. Two algorithms are provided to calculate the WMMF in different situations. A novel performance metric, the mean sidelobe level over a specified region, is also proposed to demonstrate the performance of the proposed method. Then, the SNR loss is deduced and analyzed based on several experiments. Finally, simulations and experiments based on real measured data are conducted to illustrate the effectiveness of this method. The theoretical evaluation and experiments show that the proposed WMMF can be used for all types of waveforms based on pulse compression processing and can flexibly and effectively suppress range sidelobes. Moreover, the mainlobe and the SNR loss can also be controlled by the proposed algorithms. In addition, this method can be easily applied to existing radar systems without modifying the radar transmitter or receiver.