Synthesis of Aperiodic Linear Phased Antenna Arrays Using Particle Swarm Optimization

Abstract

In this article, the particle swarm optimization (PSO) algorithm is used to synthesize an optimal linear array. The technique is applied to synthesize a linear antenna array in the Chebyshev sense or to eliminate a grating lobe. This is may be achieved by optimizing the excitation currents and/or the relative locations of the array elements. These various design parameters are considered in this paper.

In synthesizing equiripple radiation patterns, two approaches were used. The excitation currents feeding the array or the spacing between the array elements are optimized. It is to be noted that the desired equal side lobes level is achieved simultaneously with the narrowest possible beamwidth. Although the optimization problem may become nonlinear, convex, or nonconvex, especially if the interelement distances are the optimized parameters, it can be handled using the PSO algorithm. The PSO is simple to implement and does not require evaluation of gradients or coded parameters. In order to effectively utilize this algorithm, it is important to define an objective function that returns a single number to enable the PSO algorithm to minimize it. In this paper, the objective function is formulated to take into consideration both the lobe level and the main beam width. The results obtained using the particle swarm optimization technique are in excellent agreement with those available in the literature.

Keywords:

• optimization
• PSO
• linear antenna arrays

Notes

^a Normalized with respect to the edge element.

^a Normalized with respect to λ/2.