Micro-electromechanical Switched Tunable Inductor

Abstract

Disclosed is an integrated tunable inductor having mutual micromachined inductances fabricated in close proximity to a tunable inductor that is switched in and out by micromechanical ohmic switches to change the inductance of the integrated tunable inductor. To achieve a large tuning range and high quality factor, silver is preferably used as the structural material to co-fabricate the inductors and micromachined switches, and silicon is selectively removed from the backside of the substrate. Using this method, exemplary tuning of 47% at 6 GHz is achievable for a 1.1 nH silver inductor fabricated on a low-loss polymer membrane. The effect of the quality factor on the tuning characteristic of the integrated inductor is evaluated by comparing the measured result of substantially identical inductors fabricated on various substrates. To maintain the quality factor of the silver inductor, the device may be encapsulated using a low-cost wafer-level polymer packaging technique.