Planar Pattern Switchable Antenna Using Phase Reconfigurable Synthesized Transmission Lines

A new planar pattern switchable antenna is presented in this letter. The phase reconfigurable synthesized transmission line (PRSTL), capable of serving as a 1 bit phase shifter with the aid of varactor diode, is integrated into the feed network as the switching element. By changing the electrical lengths of the PRSTLs, the weighting of the vertical and horizontal current components on the radiator is controlled accordingly, hence, enabling the pattern switchability. Based on the proposed concept, an exemplum with four operating states was designed and fabricated. The measured results show that the radiation can be switched among four states, i.e., end-fire, omnidirectional, and tilted angles of 60° and 120° in the azimuth plane. The efficiency is higher than 61.4%, while the dc power consumption is less than 3.3 μW in all switching states.