Boosting MEMS Piezoelectric Transformer Figures of Merit via Architecture Optimization

Abstract

This letter documents the design and demonstration of microelectromechanical systems (MEMS) piezoelectric transformers with a measured boost in effective figure of merit as high as 4.2X. This boost is enabled by an architecture approach, which takes transformers with figures of merit limited by the inherent effective electromechanical coupling factor, ${k}_{\textsf {eff}}^{\textsf {2}}$ , and device quality factor, and provides enhanced effective transformer figures of merit through architecture optimization. This is enabled by a parallel input series out transducer architecture inspired by prior approaches with multi-layer bulk piezoelectric transformers but first demonstrated here in MEMS with discrete transformers fabricated with ~45-MHz lead-zirconate-titanate (PZT)-on-silicon electromechanical resonators.