Peak Side Lobe Reduction analysis of NLFM and Improved NLFM Radar signal
Main Article Content
Signal design is an important component for good performance of radar systems. Here, the problem of determining a good radar signal with the objective of minimizing autocorrelation sidelobes is addressed. Linear Frequency Modulated signal (LFM) is frequently used pulse compression waveform. But using LFM makes it necessary to use weighting techniques in order to reduce the side lobes which considerably decrease the SNR. At the radar receiver, the LFM signal results in first side lobe of -13dB corresponding to the main lobe. This may reduce the resultant SNR usually by 1 or 2dB. In this paper, an attempt is done to design a radar signal to attain low autocorrelation Peak Side Lobe Ratio (PSLR) which exhibits high SNR and high range resolution. In order to maintain high SNR and to get suppressed side lobes of the signal, one can use Non-Linear Frequency Modulation (NLFM). A NLFM signal is designed for different time sweeps called as Improved NLFM. In Improved NLFM the total time sweep and bandwidth are divided into Two Stage and Tri-Stage sweeps NLFM. The quality of the overall best radar signal is assessed through the parameter PSLR for different values of BT. From this analysis, it is found that the tri stage NLFM gives the low PSLR up to -17.62dB. Simulation results shows the reduction in the sidelobe level from LFM to NLFM and in Improved two and Tri-Stage NLFM.
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
All contents of the AIUB JOURNAL OF SCIENCE AND ENGINEERING Web Site are: Copyright 2019 by AJSE and/or its suppliers. All rights reserved.
 Yee Kit Chan et al., "Side lobes reduction using simple two and tri-stages nonlinear frequency modulation (NLFM)", Progress In Electromagnetics Research,29(7), vol. 98, pp. 33-52,2009
 Ch Anoosha and B.T.Krishna, “Non-Linear Frequency Modulated Radar Echo Signal Cancellation using Interrupted Sampling Repeater Jamming,” Int J Performability Eng., 2021, 17(4): 404-410
 Anoosha, C., Krishna, B.T.,“ Comparison on Radar Echo Cancellation Techniques for SAR Jamming,” Microelectronics, Electromagnetics and Telecommunications. Lecture Notes in Electrical Engineering, vol 655. Springer, Singapore, 978-981-15-3828-5_67.
 Skolnik, M. I., “Radar Handbook, McGraw-Hill”, New York, 1970.
 Keeler, R. J. and C. A. Hwang, “Pulse compression for weather radar,” Record of the IEEE 1995 International Radar Conference, 529–535, 1995.
 Johnston, J. A. and A. C. Fairhead, “Waveform design and doppler sensitivity analysis for nonlinear FM chirp pulses,” IEE Proceedings F — Communications, Radar and Signal Processing, Vol. 133, No. 2, 163–175, Apr. 1986.
 Doerry, A. W., “SAR processing with non-linear FM chirp waveforms,” Sandia Report, Sandia National Laboratories, 2006.
 Collins, T. and P. Atkins, “Nonlinear frequency modulation chirps for active sonar,” IEE Proceedings — Radar, Sonar and Navigation, Vol. 146, No. 6, 312–16, Dec. 1999.
 Barton, D. K., Modern Radar System Analysis, Artech House, Norwood, MA, 1988.
 Mahafza, B. F., Introduction to Radar Analysis, CRC Press, New York, 1998.
 Cook, C. E. and M. Bernfeld, Radar Signals: An Introduction to Theory and Application, Artech House, Boston, 1993.
 Varshney, L. R. and D. Thomas, “Sidelobe reduction for matched filter range processing,” Proceedings of the 2003 IEEE Radar Conference, 446–451, 2003.
 August, W. R., High Resolution Radar, Artech House, Boston, 1996.
 Jun Song et al., "Analysis and Detection of S-Shaped NLFM Signal Based on Instantaneous Frequency", Journal of Communications, vol. 10, no. 12, 2015. 5.
 N. Adithyavalli et al., “Modified Radar Signal Model using NLFM”, International Journal of Recent Technology and Engineering (IJRTE), Volume-8, Issue-2S3, pp. 513-516, July 2019.
 Budiman P.A. et al., "Side lobe suppression on pulse compression using curve-shaped nonlinear frequency modulation", 1st International conference on Information Technology Information Systems and Electrical Engineering (ICITISEE)
 N. Van Khanh and M. D. E. Turley, "A Range Side lobe Suppression Technique Based on Adaptive Spectral Shaping for LFM Waveforms," 2018 International Conference on Radar (RADAR), Brisbane, QLD, pp.1-6, 2018.
 J. Saeedi and K. Faez, “Synthetic aperture radar imaging using nonlinear frequency modulation signal,” IEEE Trans. Aerosp. Electron. Syst., vol. 52, no. 1, pp. 99–110, Feb. 2016.
 I. C. Vizitiu et al., "Side lobe reduction in pulse-compression radar using the stationary phase technique: An extended comparative study," 2014 International Conference on Optimization of Electrical and Electronic Equipment (OPTIM), Bran, pp. 898-901, 2014.