Seven-element ground skirt monopole ESPAR antenna design from a genetic algorithm and the finite element method

The design of an optimized electronically steerable passive array radiator (ESPAR) antenna is presented. A genetic algorithm using a finite element based cost function optimized the antenna´s structure and loading conditions for maximal main lobe gain in a single azimuth direction. Simulated gain results of 7.3 dBi at 2.4 GHz were attained along the antenna´s elemental axis. The optimized antenna was fabricated and tested with the corresponding experimental gain better than 8 dBi. The 0.7 dB error between simulated and measured gain was constant for numerous structures and therefore did not affect the optimization. The optimized antenna reduced average main lobe elevation by 15.3° to just 9.7° above the horizontal.