Analysis of Non Linear Frequency Modulation (NLFM) Waveforms for Pulse Compression Radar

Abstract

Non Linear Frequency Modulation (NLFM) method can suppress the peak sidelobe level without additional windowing function. NLFM doesn’t require any weighting function because it has inbuilt one. NLFM has a variable frequency deviation function due to the relation between frequency and time of the signal which is not linear so that it is possible to suppress of peak sidelobe level. This paper studies the characteristic of various NLFM waveform, such as NLFM Tri Stage Piece Wise (TSPW), NLFM S, and NLFM Taylor. The study of Pulse Compression of NLFM waveform consists of three aspects. First, analysis of pulse compression performance. Second, analysis of background noise. Last, analysis of Doppler effects. The simulation is done using Matlab software. The lowest value Peak Sidelobe Level (PSL)of NLFM TSPW is about -20 dB while NLFM S and NLFM Taylor are about -32 dB and -39 dB. Additive White Gaussian Noise (AWGN) and Doppler Effect influenced the value of PSL for each NLFM waveform. NLFM Taylor has the best NLFM waveform when the Doppler Effect and AWGN cause the value of PSL become high. Comparison between NLFM Taylor and Linear Frequency Modulation(LFM) is done in radar surveillance applications to analyze the detectability performance where the condition of Radar Cross Section (RCS) for each target has different significant value. The three targets are commercial airplanes, helicopter and fighter. For detectability performance, NLFM Taylor can detect more clearly than LFM conventional.

Metode Forward-Backward Capon Untuk Estimasi Parameter Pada Aplikasi Radar Multi-Antena

“…Metode estimasi parameter dengan Least Square (LS) memiliki kelemahan rendah resolusi dan memiliki sidelobes yang tinggi [4] - [5]. Disamping itu juga teknik ini memiliki deteksi amplitudo yang tidak akurat dimana amplitudo terukur proporsional dengan RCS, serta memiliki resolusi sudut yang kurang baik [6]. Hasil estimasi parameter yang berbeda jika menggunakan estimator Capon, dimana estimator ini memiliki kelebihan dapat mendeteksi lokasi target dan dapat memperkirakan amplitudo yang kompleks serta memiliki resolusi sudut yang lebih baik [7].…”

Design and Implementation Pulse Compression for S-Band Surveillance Radar

“…The Virtex®-6 FPGA ML605 Evaluation Kit [1] is the Xilinx base platform for developing system designs that demand high-performance, serial connectivity and advanced memory interfacing. This yields design applications for markets such as wired telecommunications, wireless infrastructure, broadcast and many others.…”

“…Previous works show that the Virtex®-6 FPGA ML605 Evaluation Kit [1] has been used developing system designs that demand high-performance, serial connectivity and advanced memory interfacing. In addition, integrated tools help streamline the creation of elegant solutions to complex design requirements [2].…”

Parameter Estimation and Target Detection of Phased-MIMO Radar Using Capon Estimator

“…The estimator also has a weakness in the accuracy of amplitude detection, which is proportional to RCS, and angular resolution. Detection performance is strongly influenced by the angular resolution supported by low sidelobe levels such as the use of certain waveforms [7]. Under conditions of detection with strong interference and jamming, the method does not function properly.…”