Ultra-Low-Sidelobe-Level Concentric-Ring-Array Pattern Synthesis Using Bessel Neural Networks [Antenna Designer's Notebook

2010 ◽  
Vol 52 (4) ◽  
pp. 102-105 ◽  
Author(s):  
Hassan EI-Kamchouchi
Keyword(s):  
Neural Networks ◽  
Sidelobe Level ◽  
Concentric Ring ◽  
Pattern Synthesis ◽  
Array Pattern ◽  
Low Sidelobe

Application of the Unit Circle Representation to Pattern Synthesis of Nonuniformly Spaced and Nonuniformly Excited Arrays based on the Teaching Learning Based Optimization

2019 ◽  
Vol 4 (1) ◽  
pp. 8-17
Author(s):  
Abdelmadjid RECIOUI
Keyword(s):  
Unit Circle ◽  
Antenna Array ◽  
Communication Systems ◽  
Sidelobe Level ◽  
Pattern Synthesis ◽  
Linear Arrays ◽  
Array Pattern ◽  
Teaching Learning Based Optimization ◽  
Null Placement ◽  
Teaching Learning

Pattern synthesis of Antenna array has gained much attention over the last years as they constitute an important role in the modern communication systems. Unit circle-based techniques such as Schelkunoff null placement method have proved their effectiveness to synthesize uniformly spaced linear arrays. Nonuniformly spaced antenna array pattern synthesis has been investigated and interesting results have been obtained. In this work, the unit circle representation approach is applied to synthesize nonuniformly spaced and nonuniformly excited linear arrays. The objective is to accurately place nulls in the desired directions while achieving the least possible sidelobe level. The problem is cast as an optimization problem that is solved using the Teaching Learning Based Optimization (TLBO). Examples are dealt with to prove the design approach effectiveness and flexibility for modern communication system applications.

Gravitational search algorithm for synthesis of selectively thinned concentric ring array antenna with minimum sidelobe level and with fixed and variable first null beamwidth

2014 ◽  
Vol 7 (6) ◽  
pp. 775-781 ◽  
Author(s):  
Anirban Chatterjee ◽  
Gautam Kumar Mahanti ◽  
Narendra Nath Pathak
Keyword(s):  
Search Algorithm ◽  
Gravitational Search Algorithm ◽  
Synthesis Method ◽  
Computational Time ◽  
Sidelobe Level ◽  
Concentric Ring ◽  
Pattern Synthesis ◽  
First Case ◽  
Gravitational Search ◽  
First Null Beamwidth

Thinning a large concentric ring array by an evolutionary algorithm needs to handle a large amount of variables. The computational time to find out the optimum elements set increases with the increase of array size. Moreover, thinning significantly reduces the directivity of the array. In this paper, the authors propose a pattern synthesis method to reduce the peak sidelobe level (peak SLL) while keeping first null beamwidth (FNBW) of the array fixed by thinning the outermost rings of the array based on Gravitational Search Algorithm (GSA). Two different cases have been studied. In the first case only the outermost ring of the array is thinned and in the second case the two outermost rings are thinned. The FNBW of the optimized array is kept equal to or less than that of a fully populated, uniformly excited and 0.5 λ spaced concentric ring array of same number of elements and rings. The directivity of the optimized array for the above two cases are compared with an array optimized by thinning all the rings, while keeping the design criteria same as the above two cases. The optimized array by thinning the outermost rings gives higher directivity over the optimized array by thinning all the rings. Time required for computing the optimum elements state for the above two cases using GSA are shown lesser compared to the optimized array by thinning all the rings using the same algorithm. The peak SLL and the FNBW of the optimized array for the above two cases are also compared with the optimized array by thinning all the rings.

scholarly journals Sidelobe Suppression in Array-Pattern Synthesis Using Periodic Leaky-Wave Antenna and Binomial Array

2020 ◽  
Vol 2020 ◽  
pp. 1-6
Author(s):  
Hicham Aziz ◽  
Mahmoud Moubadir ◽  
Abdelkrim Farkhsi ◽  
Naima Amar Touhami
Keyword(s):  
Antenna Array ◽  
Sidelobe Suppression ◽  
Sidelobe Level ◽  
Leaky Wave ◽  
Pattern Synthesis ◽  
Array Pattern ◽  
Leaky Wave Antenna ◽  
Wave Antenna ◽  
Measurement Results ◽  
Good Agreement

This paper presents the conception and realization of a 2D antenna array using periodic leaky-wave antenna (PLWA) and the binomial array (BA) at 6 GHz as the application of WLAN. The series array of periodic leaky-wave antenna was provided by an array of five rectangular Patches connected by cross lines. The nonuniform amplitudes of the binomial array are used to reduce the sidelobe level; in this way, the center source radiates strongly on the broadside. The prototype of the proposed 2D antenna array is designed, fabricated, and tested. A good agreement is obtained between simulated and measurement results.

scholarly journals Broadband beamforming and direction finding using concentric ring array

2005 ◽  
Author(s):  
◽  
Yunhong Li
Keyword(s):  
Sensor Arrays ◽  
Direction Finding ◽  
Side Lobe ◽  
Ring Structure ◽  
Concentric Ring ◽  
Pattern Synthesis ◽  
Element Space ◽  
Broadband Beamforming ◽  
Array Pattern ◽  
Beamformer Design

Sensor arrays have been used widely in applications including radar, sonar, seismology, biomedicine, communications and imaging. A very popular type of sensor array is circular array, which has almost invariant array pattern in azimuthal plane. This dissertation considers beamformer design and direction finding for a broadband source using concentric ring array (CRA) that contains many concentric rings of different radii. The multi-ring structure of a CRA has several advantages including the flexibility in array pattern synthesis and adaptive array design. We first proposed three CRA array pattern synthesis techniques, which can be used to control the side lobe and/or main lobe width of the array pattern of a deterministic broadband beamformer. We then proposed a flexible partially adaptive broadband beamformer design based on element-space approach. Finally, we proposed an efficient direction finding technique for broadband source using CRA. The proposed design techniques are corroborated by experiments from simulated as well as measured data.

Chebyshev-based array for beam steering and null positioning using modified ant lion optimization

2021 ◽  
pp. 1-15
Author(s):  
Hrudananda Pradhan ◽  
Biswa Binayak Mangaraj ◽  
Santanu Kumar Behera
Keyword(s):  
Beam Steering ◽  
Optimization Algorithms ◽  
Optimization Methods ◽  
Main Beam ◽  
Design Parameters ◽  
Sidelobe Level ◽  
Pattern Synthesis ◽  
Ant Lion Optimization ◽  
Array Pattern ◽  
Ant Lion

Abstract A modified ant lion optimization (MALO) algorithm is proposed in this article, for the synthesis of Chebyshev-based arrays by optimizing amplitudes and phases of excitations, and element spacings. Modification in ant lion optimization is achieved by hybridizing it with chaotic particle swarm optimization. The optimization process is employed to obtain an array pattern with the least possible sidelobe level. Close-in sidelobe level minimization for optimum pattern synthesis is suggested. Instead of only steering the main beam towards the desired direction presented by some popular optimization methods, the beam steering along with null positioning in other specified direction is also achieved employing MALO. Considering the arrays with the same design parameters and the results of other optimization algorithms, the performance of MALO is evaluated. The results show that MALO provides considerable improvements in an array pattern compared to the arrays optimized using other optimization algorithms and the uniform array.

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