Design of electrically small wire antennas using genetic algorithm taking into consideration of bandwidth and efficiency

Altshuler (see (see 2001 USNC/URSI Nation Radio Science Meeting, p.226, Salt Lake City, UT, July 2000)) reported on the use of genetic algorithm (GA) for designing electrically small wire antennas. The wire configuration that results in maximum bandwidth was generated using the GA for a given antenna size. However, it is well known that antenna miniaturization impacts antenna efficiency as well as bandwidth. We consider the use of the GA for designing electrically small wire antennas taking into consideration both bandwidth and efficiency. For the antenna configuration, we employ the multi-segment structure similar to that used by Altshuler. The Numerical Electromagnetics Code (NEC) is used to predict the performance of each wire structure. To efficiently map out the multi-objective problem, we implement a Pareto GA approach. An optimal set of designs that consider bandwidth, efficiency and antenna size is generated. The performance curve achieved by the GA approach is also compared against the well-known fundamental limit of small antennas. Finally, to verify our GA results, several GA designs are built, measured and compared to the simulation.