Tuning antennas with EFFA RF-MEMS

Abstract

A single production thin film work-flow is presented to monolithically integrate a new type of RF-MEMS variable capacitor, the electrostatic fringing-field actuator (EFFA) in tunable planar antennas. Only two lithographic steps are necessary, which significantly reduces production costs when applied at a large scale. It is shown that the RF-MEMS used is ideal for use in a topology that enables slight antenna tuning, for example hopping between slightly separated frequency bands (the IEEE 802.11a European and USA bands of 5.25 GHz and 5.6 GHz, for example). The study points out the possibilities, limits, and challenges of the EFFA and its fabrication technology in combination with antennas. The novelty is thus to assess this technology for producing planar antennas involving RF-MEMS of the EFFA type.