Optimized Weighting of Uniform Subarrays of Unequal Sizes

Abstract

Amplitude weighting at the subarray outputs alone causes grating lobes in array factors. An approach that disrupts the periodic quantization by dividing the array into subarrays of unequal sizes and amplitude weighting at the subarray ports is presented. A hybrid genetic algorithm optimizes the subarray size and subarray weights to minimize the maximum sidelobe level.

Adaptive Antenna Arrays for Ad-Hoc Millimetre-Wave Wireless Communications

“…The digital beamformer estimates the AoA information to control the phases of the phase shifters in the analogue sub-arrays and also adjusts the digital weights applied to the subarray output signals to form a beam. Sub-array technology has been used over the past decades (Abbaspour-Tamijani & Sarabandi, 2003;Goffer et al, 1994;Haupt, 2007;Mailloux, 2005Mailloux, , 2007. Prior ideas include employing a time delay unit to each phased sub-array for bandwidth enhancement, and eliminating phase shifters in the sub-array for applications requiring only limited-field-of-view.…”

Novel Fractal Antenna Arrays for Satellite Networks: Circular Ring Sierpinski Carpet Arrays Optimized by Genetic Algorithms

“…They have been proven efficient to finding the proper excitations or the suitable division of the arrays in sub-arrays in order the antenna to produce a desired radiation pattern with respect to the SLL and the directions of the nulls or to optimize the antenna by broadening the frequency bandwidth [11,[15][16][17][33][34][35]. GAs have also been used to thin an array [18], in combination with Particle Swarm Optimization Technique to modify sparse arrays [21] or to modify fractal arrays [29,36].…”

“…A widely used technique is to separate the array in sub-arrays, fed by properly weighted excitations [11,12]. Innovative techniques, based on the architecture of the arrays, that effectively solve both the problems of grating lobes and the large number of control points have been recently proposed: a) the sparse arrays synthesized by uniformly excited elements located onto a non-regular grid and b) the thinned arrays that are produced from initial regular arrays by properly withdrawing a certain number of elements.…”

Sidelobe Reduction Through Element Phase Control in Uniform Subarrayed Array Antennas

“…The same goal has been yielded in [3] by means of sub-array amplitude tapering, while the size of the sub-arrays has been optimized in [4]. On the other hand, the joint optimization of the sub-array sizes and weights has been considered in [5]. In regard to planar arrays, various methods based on the sub-array rotation [6], the use of a-periodically spaced sub-arrays [7], and a tiling strategy with sub-arrays of different shapes [8] have been presented.…”