Authors: M. Motiee, A. Khajepour and R.R. Mansour
Affilation: University of Waterloo, Canada
Pages: 295 - 298
Keywords: RF MEMS, bandpass filters, MUMPs, intermediate frequency MEMS
MEMS based mechanical resonators and filters have shown promising characteristics in achieving high Q values and good stability. This paper introduces a novel V-shape coupling element that is used to mechanically couple two clamped-clamped MEMS resonators laterally. The stiffness of the proposed V-shape coupling element is adjustable via changing the length of the V sidelines and/or the V conjunction angle to flatten the filter passband. In previous literature, only a single resonator in lateral vibration is considered. No suggestions were given on the coupling of such type of resonators. In this work a V-shape coupling and two beam elements are used to construct a 2-pole bandpass filter operating in the intermediate frequency (IF) range. It is fabricated using the PolyMUMPs process. A lumped modeling approach is presented, which allows a fast and accurate modeling and optimizing of the structures. With the help of finite element analysis, the validity and accuracy of the lumped modeling is investigated. Filters have been fabricated and tested. Presented filters have center frequencies varying from 700 kHz to 1.7 MHz, quality factors of 300 to 1500 when tested in a non-vacuum chamber.