A compact and reconfigurable beam pattern ESPAR antenna with automatic impedance matching system

A compact ESPAR antenna that is composed of 1 active-RF element and 6 parasitic elements surrounding driven element is proposed in this paper. This antenna is operated at 915 MHz and reconfigurable beam patterns that changed not only beam angel but also beam width. Any beam patterns form, it is available to radiate and minimize the return loss by using automatic impedance matching system. The achievable realized gain is from 3.12 dBi to 4.8 dBi.