Lithium Niobate for M/NEMS Resonators

Abstract

Piezoelectric Radio frequency (RF) microelectromechanical systems (MEMS) resonators are chip-scale components embedded in the modern RF front ends to carry out the function of frequency selection and interference rejection. They are the building blocks of RF filters and oscillators. Their working principle leverages piezoelectric thin films to covert resonance phenomenon from the mechanical to the electrical domain. Piezoelectric MEMS resonators are still being extensively researched with the main focus placed on attaining the optimal combination of electromechanical coupling, higher Q, and wafer-level frequency agility. The intense development of piezoelectric MEMS resonators was triggered in the past decade by the demand for high-precision timing sources and high-performance filtering devices to address telecommunication needs in an already-crowded RF spectrum. Particularly, fueled by the fast growth of consumers and services in the mobile marketplace, the demand for bandwidth has resulted in increasingly stringent performance specifications for front-end filters and duplexers. In order to accommodate the emerging standards in the RF spectrum, the development of piezoelectric MEMS resonators faces many new challenges, including lower loss, wider bandwidth performance, better temperature stability, high power handling and linearity, and most important of all, frequency tunability and agility.