scholarly journals Uniform Rectangular Array Synthesis and Optimization Using Modified Genetic Algorithm

2020 ◽  
Author(s):  
Mercy Sheeba J ◽  
S. Deepa
Keyword(s):  
Genetic Algorithm ◽  
Side Lobe ◽  
Beam Pattern ◽  
Side Lobe Level ◽  
Azimuthal Direction ◽  
Rectangular Array ◽  
Modified Genetic Algorithm ◽  
Simulation Results ◽  
Optimum Solution ◽  
Uniform Rectangular Array

This paper aims to synthesize a uniform rectangular array (URA) which spans beamwidth of -30∘ to 30∘ in the azimuthal direction with the interference direction as 40∘ in the azimuth plane. In this paper, a Modified Genetic Algorithm is proposed which works to produce a beam pattern with a narrow beamwidth, high directivity and maximized side lobe level (SLL) suppression. The simulation results for the proposed algorithm demonstrates that the synthesized beam pattern for a 16x16 URA at a frequency of 1 GHz converges to the desired optimum solution producing a maximum SLL suppression of -30dB.

scholarly journals Null Steering in Failed Antenna Arrays

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Om Prakash Acharya ◽  
Amalendu Patnaik ◽  
Sachendra N. Sinha
Keyword(s):  
Antenna Array ◽  
Antenna Arrays ◽  
Side Lobe ◽  
Side Lobe Level ◽  
Correction Procedure ◽  
Swarm Optimization ◽  
Array Pattern ◽  
Null Steering ◽  
Simulation Results ◽  
Pattern Simulation

Antenna array pattern nulling is desirable in order to suppress the interfering signals. But in large antenna arrays, there is always a possibility of failure of some elements, which may degrade the radiation pattern with an increase in side lobe level (SLL) and removal of the nulls from desired position. In this paper a correction procedure is introduced based on Particle Swarm Optimization (PSO) which maintains the nulling performance of the failed antenna array. Considering the faulty elements as nonradiating elements, PSO reoptimizes the weights of the remaining radiating elements to reshape the pattern. Simulation results for a Chebyshev array with imposed single, multiple, and broad nulls with failed antenna array are presented.

scholarly journals Iterative GA Optimization Scheme for Synthesis of Radiation Pattern of Linear Array Antenna

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Sarayoot Todnatee ◽  
Chuwong Phongcharoenpanich
Keyword(s):  
Genetic Algorithm ◽  
Radiation Pattern ◽  
Linear Array ◽  
Weight Coefficient ◽  
Side Lobe ◽  
Array Element ◽  
Array Antenna ◽  
Side Lobe Level ◽  
Optimization Scheme ◽  
Iterative Optimization

This research has proposed the iterative genetic algorithm (GA) optimization scheme to synthesize the radiation pattern of an aperiodic (nonuniform) linear array antenna. The aim of the iterative optimization is to achieve a radiation pattern with a side lobe level (SLL) of ≤−20 dB. In the optimization, the proposed scheme iteratively optimizes the array range (spacing) and the number of array elements, whereby the array element with the lowest absolute complex weight coefficient is first removed and then the second lowest and so on. The removal (the element reduction) is terminated once the SLL is greater than −20 dB (>−20 dB) and the elemental increment mechanism is triggered. The results indicate that the proposed iterative GA optimization scheme is applicable to the nonuniform linear array antenna and also is capable of synthesizing the radiation pattern with SLL ≤ −20 dB.

scholarly journals Construction of Waveform Library in Cognitive Radar

2017 ◽  
Vol 24 (s2) ◽  
pp. 22-29 ◽  
Author(s):  
Guo Yongqiang ◽  
Wu Yumin ◽  
Liu Hui
Keyword(s):  
Fourier Transform ◽  
Coordinate Transformation ◽  
Fractional Fourier Transform ◽  
Side Lobe ◽  
Ambiguity Function ◽  
Side Lobe Level ◽  
Cognitive Radar ◽  
Motion Parameters ◽  
Simulation Results

Abstract Based on the thoughts of cognitive radar, Fractional Fourier Transform (FrFT) is used to generate a rotatable waveform libraries of Frank coded/Barker coded waveform in this paper. Then, the ambiguity function is used to analyze the delay resolution, Doppler resolution, delay side-lobe level, and Doppler side-lobe level of the waveform libraries and orthogonality of them is also analyzed. Furthermore, we proved theoretically that there is a fixed coordinate transformation between the waveforms of library and its origin waveform. Therefore, the Cramér-Rao low bound (CRLB) of motion parameters can be computed easily using the waveforms of the libraries, which facilitate the subsequent waveform scheduled work. Simulation results show that the library waveforms can reduce delay resolution to satisfy the different situations and can bring significant benefits for delay resolution, orthogonality and reuse interval.

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