Dynamic phase-only array beam control using a genetic algorithm

Abstract

This paper describes two approaches to evolvable antenna array beams. The first approach uses a genetic algorithm for adaptive phase-only nulling with phased arrays. A genetic algorithm adjusts some of the least significant bits of the beam steering phase shifters in order to minimize the total output power. Using a few bits for nulling speeds convergence of the algorithm and limits pattern distortions. Various results are presented to show the advantages and limitations of this approach. A second problem is a switched beam linear array in which two beams with specified shapes, a narrow beam and a wide beam, are to be produced. The goal of the design effort is to determine a set of complex excitation coefficients such that switching between beams is accomplished by changes in the phase weights alone. Excellent results are obtained by simultaneous, multi-objective optimization based design using a GA instead of sequential GA optimization for the narrow and wide beam cases individually.