Anti-jamming property of Colpitts-based direct chaotic through-wall imaging radar

Abstract

A direct chaotic through-wall imaging (TWI) radar using chaotic signal generated by improved Colpitts oscillator is proposed, and its good anti-jamming performance is investigated theoretically and experimentally. Compared with conventional TWI radar, the proposed radar has the advantages of very high range resolution, low probability of intercept, and immunity from jamming and interference. The characteristics of the chaotic signal are presented. According to the delta function-like autocorrelation of the chaotic signal, the range resolution of the radar is 6 cm. The cross-ambiguity functions with no discernible peaks are used to theoretically certify its interference immunity performance, and then the anti-jamming properties in the Colpitts jamming, linear frequency modulated chirp jamming, and noise jamming environments are demonstrated by numerical electromagnetic simulations using finite difference time domain, and the corresponding experiments. The simulation and experimental results show that the chaotic waveform possesses excellent jamming immunity to the noise and radio frequency interference. This feature makes the chaotic signal perform superbly in multi-radar environments.