Summary: 78 JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 17, NO. 1, FEBRUARY 2008
MEMS Switched Tunable Inductors
Mina Rais-Zadeh, Student Member, IEEE, Paul A. Kohl, Member, IEEE, and Farrokh Ayazi, Senior Member, IEEE
Abstract--This paper presents a new implementation of inte-
grated tunable inductors using mutual inductances activated by
micromechanical switches. To achieve a large tuning range and a
high quality factor, silver was used as the structural material, and
silicon was selectively removed from the backside of the substrate.
Using this method, a maximum tuning of 47% at 6 GHz is achieved
for a 1.1 nH silver inductor fabricated on a low-loss polymer
membrane. The effect of the quality factor on the tuning charac-
teristic of the inductor is investigated by comparing the measured
result of identical inductors fabricated on various substrates.
To maintain the quality factor of the silver inductor, the device
was encapsulated using a low-cost wafer-level polymer packaging
Index Terms--Inductors, micromachining, quality factor,
switches, tunable inductor, tuning.
TUNABLE inductors can find application in frequency-