A new high-gain and low-complexity pattern-reconfigurable antenna

A new pattern-reconfigurable antenna, which operates from 2.36 GHz to 2.55 GHz and has maximum directivity 7.2 dB at horizontal plane, is presented in this work. In contrast to prior art designs, there is no ground plane, which usually displaces the directivity main lobe from the horizontal plane. In this paper, the main-lobe elevation angle is zero. The antenna is an Electronically Steerable Parasitic Array Radiator (ESPAR) antenna, based on Yagi-Uda concept, and utilizes printed elements on low-cost FR-4: a bow-tie dipole (driven-element) was surrounded by eight bow-tie parasitic-elements. The latter, which can be open or short-circuited using voltage-control RF switchers, act as directors or reflectors and hence accurately control the radiation pattern. The antenna was analyzed in terms of reflection coefficient and directivity and finally was fabricated and measured. Measurements agree well with simulations.