Design and Simulation of an IF MEMS Filter Based on Face Shear Mode Square Resonator

Abstract

Intermediate frequency (IF) Filters with IC (Integrated circuit) compatibility, narrow bandwidth and large stop band rejection are in need for wireless communications. This paper presents the design and simulation of a 70 MHz IF Micro-electro-mechanical filter using two identical face shear mode square resonators. By carefully designing the supporting structure of the resonators, a quality factor above 100,000 is achieved in the best designed resonator. With these face shear mode square resonators, three filters are designed and the simulated transmission response shows that these filters can obtain unterminated transmission passbands of about 25 kHz to 35 kHz with the centre frequency of 70 MHz, which represents a 0.036% to 0.05% bandwidth. This ultra narrow bandwidth IF bandpass filter can be an attractive candidate for wireless receivers.