Reducing the grating lobes and main lobe width for increasing range resolution using phase and frequency modulated codes

In Radar the good range resolution can be achieved by a short pulse. Short pulse systems are limited resolution because they are narrow band. Using pulse compression technique high range resolution can be achieved in radar system. The barker codes are known as bi-phase codes with minimum side lobes used in phase modulation in pulse compression technique. LFM and NLFM codes are used as frequency modulation. In this paper the wide band signals that is LFM and NLFM codes are modulates Barker codes to get good resolution while getting minimum side lobes and reduction in main lobe width. By introducing LFM in Barker codes grating lobes will be appeared in Autocorrelation function of LFM Barker sequence. To reduce the grating lobes and the main lobe width to get high delay and Doppler resolution, NLFM code is introduced in Barker codes and observed merit factor, side lobe levels, main lobe width and Doppler tolerance from Autocorrelation function as well as ambiguity function.

[1]  Sridevi Katamaneni,et al.  Mainlobe Width Reduction Using Linear and Nonlinear Frequency Modulation , 2009, 2009 International Conference on Advances in Recent Technologies in Communication and Computing.

[2]  Martin H. Ackroyd,et al.  Optimum Mismatched Filters for Sidelobe Suppression , 1973, IEEE Transactions on Aerospace and Electronic Systems.

[3]  Iulian Constantin Vizitiu.  SIDELOBES REDUCTION USING SYNTHESIS OF SOME NLFM LAWS , 2013 .

[4]  Charles E. Cook,et al.  Radar Signals: An Introduction to Theory and Application , 1967 .

[5]  R. Mayer,et al.  Longest binary pulse compression codes with given peak sidelobe levels , 1986, Proceedings of the IEEE.

[6]  Pulse Compression , .

[7]  Armin W. Doerry,et al.  Generating nonlinear FM chirp waveforms for radar. , 2006 .

[8]  M. Skolnik,et al.  Introduction to Radar Systems , 2021, Advances in Adaptive Radar Detection and Range Estimation.