Sidelobe Reduction in the Pulse-Compression Radar Using Synthesis of NLFM Laws

Iulian-Constantin Vizitiu

doi:10.1155/2013/605604

Abstract

It is well known that in the pulse-compression radar theory, the sidelobe reduction using synthesis of some proper nonlinear FM (NLFM) laws represents a major research direction. In order to assure the sidelobe suppression, the main objective of this paper is to present an adequate synthesis algorithm of NLFM signals based on stationary phase principle. The achieved experimental results confirm a significant sidelobe reduction (i.e., more than −40 dB) without necessity to apply some weighting techniques. In addition, the analysis of the synthesized NLFM laws by ambiguity function tool is also discussed.

Highlights

According to the literature [1, 2], it is well known that the signal compression techniques are used inside of all modern radar systems to increase the range resolution without having to increase the peak transmit power
In order to assure the sidelobe suppression, the main objective of this paper is to present an adequate synthesis algorithm of nonlinear FM (NLFM) signals based on stationary phase principle
Having as starting point the experimental results reported in [14,15,16], it seems that very good results have been obtained in case of Taylor and Blackman-Harris weighting windows as sidelobe reduction techniques, and these two types of PSD functions will be used for synthesis and comparative analysis of the matched NLFM laws by the previously described algorithm

Summary

Introduction

According to the literature [1, 2], it is well known that the signal (pulse-) compression techniques are used inside of all modern radar systems to increase the range resolution without having to increase the peak transmit power. The NLFM signals are other continuous phase modulation waveforms with applicability inside of pulsecompression radar systems They have been claimed to provide a high-range resolution, an improved signal to noise ratio (SNR), low cost, and good interference mitigation. They have a spectrum weighting function inherently in their modulation function, which offers the advantage that a pure matched filter gives low sidelobes (the loss in SNR associated with weighting or with the usual mismatching techniques is eliminated). According to [5], the NLFM waveforms assure the better detection rate characteristics and is more accurate in range determination than other consecrated processing methods (e.g., dual apodization (DA), spatially variant apodization (SVA), leakage energy minimization (LEM), etc.)

Objectives

Results

Conclusion