Side lobe reduction of a concentric circular antenna array using genetic algorithm

Abstract

A concentric circular antenna array (CCAA) consists of elements positioned on the periphery of imaginary circles on a plane having a common centre and different radii. The simplest way to feed the elements of such an array is to use uniform excitation. However, with a non-uniform excitation profile, considerable reduction of the side lobe level (SLL) may be achieved at the cost of the added complexity. The difference of SLLs (with respect to the uniform excitation case) becomes even more prominent when the beamwidth of the antenna needs to be kept fixed. In this paper, we formulate the task of designing a non-uniformly excited CCAA as a constrained optimization problem and use genetic algorithm (GA) to solve the same. The goal is to determine an optimum set of weights for antenna elements which provides a radiation pattern with maximum SLL reduction with the constraint of a fixed beamwidth

Optimum Design of ThinWideband Multilayer Electromagnetic Shield Using Evolutionary Algorithms

“…The basic concept of PSO [12,13,18] algorithm which is based on the swarm behavior of insects, animals herding, birds flocking and fish schooling was first developed and introduced by Kennedy and Eberhart in 1995 where the search pattern of each swarm is adapted from its own as well as other members experience. In PSO every individual member of the swarm is called particle and it represents the potential solution which is a point in the search space and the global optimum is the location of the food.…”

“…Which has been solved successfully using different evolutionary algorithms [10,11]. This paper mainly focused on the optimum designing of thin wideband (900-1800MHz) perforated multilayer electromagnetic shield using Particle Swarm Optimization algorithm (PSO) [12,13,18] and Genetic Algorithm (GA) [11,[13][14][15][16][17]. During the problem formulation the total mass and cost of the shield, corresponding to the shielding effectiveness of the multilayer structure is considered to make the design practically more significant.…”

Invasive Weed Optimization (IWO) Algorithm for Control of Nulls and Sidelobes in a Concentric Circular Antenna Array (CCAA)

“…CCAA are more versatile and can provide more symmetric patterns with lower sidelobe levels. CCAA has the advantage of all azimuthal scan capability [2,3].…”

“…The m th (m=1, 2…M) ring has a radius of r m and contains N m elements. Assuming the elements are isotropic, the array factor can be written as shown in equation 1 [3,4].…”

Synthesis of thinned concentric circular antenna arrays using teaching-learning-based optimization

“…Furthermore, uniform CCAAs provide invariant azimuth angle coverage, which makes CCAAs the favored choice in the direction of arrival applications. Therefore, recently, the design of circular antenna arrays with minimum side lobes levels has been a subject of very much interest in the literature [2][3][4][5][6][7].…”