RF MEMS/NEMS resonators for wireless communication systems and adsorption-desorption phase noise

Abstract

During the past two decades a considerable effort has been made to develop radio-frequency (RF) resonators which are fabricated using the micro/nanoelectro-mechanical systems (MEMS/NEMS) technologies, in order to replace conventional large off-chip components in wireless transceivers and other high-speed electronic systems. The first part of the paper presents an overview of RF MEMS and NEMS resonators, including those based on two-dimensional crystals (e.g. graphene). The frequency tuning in MEMS/NEMS resonators is then analyzed. Improvements that would be necessary in order for MEMS/NEMS resonators to meet the requirements of wireless systems are also discussed. The analysis of noise of RF MEMS/NEMS resonators and oscillators is especially important in modern wireless communication systems due to increasingly stringent requirements regarding the acceptable noise level in every next generation. The second part of the paper presents the analysis of adsorption-desorption (AD) noise in RF MEMS/NEMS resonators, which becomes pronounced with the decrease of components' dimensions, and is not sufficiently elaborated in the existing literature about such components. Finally, a theoretical model of phase noise in RF MEMS/NEMS oscillators will be presented, with a special emphasize on the influence of the resonator AD noise on the oscillator phase noise.