A novel MEMS-based wideband frequency tunable microstrip patch antenna

This paper presents a novel micromachined wideband frequency tunable microstrip patch antenna. The fabrication process of the proposed reconfigurable antenna system is composed of a process combination of bulk and surface micromachining. Thermal actuation is employed as the driving mechanism. The out-of-plane motion of the thermal actuators normal to the antenna surface deflects the patch downward respect to the fixed ground plane. This deflection decreases the air gap height beneath the patch and consequently, resonant frequency of the antenna. The up-state operating frequency of the antenna is 22.19GHz. A tuning range of 334MHz is achieved by the CMOS compatible actuation voltage of 2.65V. Simulations show a bandwidth of 1.26 and 1.17GHz for up and down-state (5µm deflection) positions, respectively. The microwave performance of the antenna and its mechanical behavior is investigated by finite-element analysis and good radiation pattern and return loss are obtained within the tuning range.