Designing Polyphase code for Digital Pulse Compression for surveillance Radar

Digital Pulse compression is a technique to achieve better range resolution that of corresponding short pulse by transmitted power of a reasonably long pulse. Compare to other radar waveform codes, Polyphase codes have the ability to achieve better side lobe levels without applying weighting functions. More importantly, Polyphase wave forms have the advantages of low main lobe width, high peak side lobe ratio and better Doppler tolerance, a vital parameter to extract the target's velocity. In this paper, the authors would like to analyze Digital Pulse Compression technique for radar application, using Polyphase codes and summarize the comparison between different Polyphase in terms of main lobe width, side lobe reduction, Doppler tolerance and analyze the effect of pre-compression band-limiting. The advantages of Polyphase codes and waveform design criteria for the S-band Radar application is also discussed in this paper.