Electrically small linear antennas generated with a genetic algorithm

In this article we report on the use of a genetic algorithm (GA) in the design of electrically small linear antennas, taking into consideration the lowest VSWR and the best antenna gain. For the antenna configuration, we employ a multisegment wire structure. Our antenna structures resemble a monopole over the perfectly conducting ground plane. The arm of the monopole is the set of a fixed number of connected linear wire segments. All segments are the same length. Each segment of the antenna is bounded by a hemispheric space with a given radius. The total length of a monopole is constant. To achieve efficient set of designs, trading off VSWR and gain we use GA in conjunction with algorithm which creates initial population of antennas. In our GA each wire shape is encoded into a chromosome. The total size of chromosome depends on number of wire segments. After operation of reproduction, crossover and mutation several antennas structures are generated. To predict the performance of generated antennas we use the numerical electromagnetics code.