Contour mode piezoelectric ring micro-resonators on Si for series resonant converters

Microelectromechanical systems (MEMS) resonators on Si have the potential to replace discrete L-C components in series resonant converters. With acoustic coupling rather than inductive coupling, these MEMS resonators achieve better electromagnetic interference (EMI) performance, and reduce size, weight and volume of the power converter. In this paper, ring shaped piezoelectric microresonators are presented. These resonators vibrate in contour mode achieving a low resonant frequency, thus implementation in power converter circuits is possible. COMSOL Multiphysics simulation results have been provided showing the mode of vibration at resonance. A CMOS compatible fabrication process has been proposed and implemented. In addition, the fabricated devices have been characterized and experimental results are detailed. Finally, a PSIM simulation of a series resonant inverter incorporating the equivalent electrical model of the resonator has been performed.