Enhanced Radar Performance using Optimized Hybrid Signal based on Nonlinear and Linear Frequency Modulation

Nonlinear frequency modulated (NLFM) waveforms are widely used in radar applications due to their low range sidelobes and high range resolution. In this paper, we propose an optimized hybrid radar signal based on linear and sigmoidal S-shapes using particle swarm optimization (PSO). The proposed signal achieves a significantly reduced sidelobe level while preserving mainlobe width, making it suitable for various radar applications. The proposed signal also exhibits the desirable Doppler tolerance property. The analytical description of the proposed signal and the optimization process using PSO are presented in detail. The performance of the proposed signal is evaluated under Doppler effect, and its limitations are discussed. The results show that the proposed signal outperforms existing linear and nonlinear waveforms in terms of sidelobe suppression, and mainlobe width with fair Doppler tolerance.