Doppler-tolerant NLFM Radar Signal Synthesis Method

The problem of designing a radar NLFM waveform with reduced Doppler sensitivity is examined in this paper. A presented novel approach utilizes a U-shaped instantaneous phase functions to determine a signal time-frequency structure combined with optimization framework aimed to reach compromise between sidelobe attenuation and range resolution with additional requirement on Doppler tolerance. Spectral efficiency of the signal is also examined and accounted for. This aspect has been rarely discussed to date, whereas it needs to be considered in practical implementation due to the limits arising from band allocation and interference mitigation point. The simulation results show that the signals synthesized with proposed method reach sidelobes level as low as -50 dB without any amplitude modulation. Finally, improved Doppler tolerance makes proposed waveform attractive for surveillance radar.