Adaptive beamforming of ESPAR antenna based on stochastic approximation theory

A novel approach based on stochastic approximation theory is devoted to adaptive beamforming of electronically steerable passive array radiator (ESPAR) antennas. Because of the low cost, the ESPAR antenna has only a single-port output. The proposed algorithm, by unconventional method, performs adaptive control of loaded reactances on the passive radiators and thus forming both beam and nulls. Our study and simulation results show that ESPAR antenna can effectively suppress interference and noise background and is attractive in modem wireless communications systems.