Evaluation of the Adaptive Beamforming Capability of an ESPAR Antenna Using the Genetic Algorithm

The electrically steerable parasitic array radiator (ESPAR) antenna, which is expected to be a key component in wireless ad hoc networking, is a single-output array. Because it is not possible to observe the output signal of each element of the antenna, it is impractical to directly apply most of the algorithms designed for conventional array antennas. Therefore, to evaluate the adaptive beamforming capability of the ESPAR antenna, the genetic algorithm (GA) is applied and the results are compared with those obtained by applying the steepest-gradient algorithm (SGA) to the ESPAR antenna. The GA results reveal that the ESPAR antenna possesses the ability to form a beam and null at the same time, even when the angular difference between the desired and interference signal is less than 60 degrees