Novel narrowband radio frequency microelectromechanical systems filters

Abstract

Abstract This work presents three new narrowband radio frequency (RF) microelectromechanical systems (MEMS) filters made from mechanical or electrically coupled resonators with a quality factor Q of over 10 000. A low-stiffness rectangular-frame mechanical coupling beam (RFCB) is designed, and a filter with an RFCB is successfully developed with a center frequency of 75.5 MHz and a percent bandwidth (BW) of 0.4%. In addition, a tunable narrowband filter is achieved with a mechanically coupled four-disk linear structure filter. The center frequencies are 74.47 ± 0.54 MHz and the percent BW range is 0.48%–2.2%. In order to further simplify the architecture of the filter, a filter based on a single whisper gallery mode disk resonator is demonstrated, which has a center frequency of 79.42 MHz and a BW of only 0.25%. The three different RF MEMS filters have potential applications in wireless communication systems.