Design and performance analysis of inter-pulse frequency coded and intra-pulse linear frequency modulation composite waveform

Abstract

Modern battlefield environment is complex and changeable. In addition to having higher target resolutions, airborne radar should also have good radio frequency (RF) stealth performance such as large time-bandwidth product, low interception factor, low power spectrum density (PSD) amplitude, etc. There are the high distance grating lobes after pulse compression in the large frequency interval of Costas signal. After Costas is modulated by linear frequency modulation, we can obtain the inter-pulse frequency coded and intra-pulse linear frequency modulation (Costas-LFM) signal. Compared with Costas signal with large frequency interval, Costas-LFM signal eliminates distance grating lobes, obtain the large bandwidth, increases the complexity of the intra-pulse frequency modulation features and the difficulty of sorting and identification of the passive detection system. Simulations show that Costas-LFM signal is significantly improved in ambiguity function, autocorrelation function (ACF), PSD and interception factors. While realizing radar detection, the signal also has good RF stealth performance, which has a wide application prospect in modern war.