Microstrip antenna tuning using variable reactive microelectromechanical systems

Due to their small size, low loss, and compatibility with integrated circuits, microelectromechanical systems (MEMS) have been the focus of recent efforts at developing frequency reconfigurable patch antennas able to operate at a number of different user-selected frequencies. Although reactive loading with MEMS variable capacitors is a well-documented method in reconfigurable antenna design, MEMS variable inductors have not received the same attention in that role. Designs for frequency tunable patch antennas using MEMS variable inductors and capacitors are presented here. Variations on previous thermally actuated MEMS variable inductors and electrostatically actuated MEMS variable capacitors fabricated through a multi-user surface micromachining process are tested and shown to successfully vary reactance when actuated. Microstriped patch antennas loaded with discrete surface-mount reactive components were successfully tested to demonstrate the principle of this MEMS application.