Effects of Highpass Filtering on Transmitted Signals of Non-Linear Frequency Modulated Radar Systems
Keywords:Non-linear frequency modulation, highpass filter, matched filter, auto-correlation, peak sidelobe level
This paper presents an advantage of highpass filtering of a transmitted signal of nonlinear frequency modulated (NLFM) radar systems. Radar systems use NLFM signals for sidelobe level reduction in the output of the matched filter (MF). This paper suggests a further reduction in sidelobe levels of output of matched filters by highpass filtering. The output of matched filter is the autocorrelation of the input signal. Numerical simulations are performed on highpass filtered NLFM signals and the results obtained are compared with conventional linear frequency modulated (LFM) signal. From these results, it is proposed that highpass filtering on NLFM can be used to further improve the output of the matched filter considerably by reducing relative sidelobe levels.
Peyton Z Peebles, Radar principles. John Wiley & Sons, 2007.
Kelly, E. J., and R. P. Wishner. "Matched-filter theory for highvelocity, accelerating targets." IEEE Transactions on Military Electronics 9, no. 1 (1965): 56-69.
Scheer, Jim, and William A. Holm. Principles of modern radar. Edited by Mark A. Richards, and William L. Melvin. SciTech Pub., 2010.
Pang, Chen, Peter Hoogeboom, François Le Chevalier, Herman WJ Russchenberg, Jian Dong, Tao Wang, and Xuesong Wang., "A pulse compression waveform for weather radars with solidstate transmitters," IEEE Geoscience and Remote Sensing Letters 12, no. 10 (2015): 2026-2030.
Farshchian, Masoud, and Gregory E. Coxson. "Multi-rate convolution for LFM and NLFM." In Radar Conference, 2009 IEEE, pp. 1-5. IEEE, 2009.
Saeedi, Jamal, and Karim Faez. "Synthetic aperture radar imaging using nonlinear frequency modulation signal." IEEE transactions on aerospace and electronic Systems 52, no. 1 (2016): 99-110.
Yang, Jie, and Tapan K. Sarkar. "A new doppler-tolerant polyphase pulse compression codes based on hyperbolic frequency modulation." In Radar Conference, 2007 IEEE, pp. 265-270. IEEE, 2007.
Zhou, Meng, Jun Jason Zhang, and Antonia PapandreouSuppappola. "Hyperbolic frequency modulation for multiple users in underwater acoustic communications." In Acoustics, Speech and Signal Processing (ICASSP), 2014 IEEE International Conference on, pp. 3498-3502. IEEE, 2014.
David M Pozar, Microwave engineering. John Wiley & Sons, 2009.
MATLAB, version 7.10.0 (R2010a). The MathWorks Inc., 2010.