Enhancing Piezo-MEMS Transformer Performance

Abstract

This paper documents an architecture approach using extensional mode harmonics to improve the figures of merit (TxFoM) of thin-film piezoelectric MEMS transformers. Modeling of this approach reveals multi-fold improvements in TxFoM as well as the significance and impact of transducer electrical quality factor. Experimental results with PZT-on· $4\mu \mathrm{m}$ Si and AlN transformers verify this architecture approach and show up to 4.3X and 4.4X TxFoM improvements, respectively. These are demonstrated with −63MHz PZT-on-Si and ~69 MHz AlN piezoelectric transformers. Measurement results also reveal the importance of routing resistance and parasitics and their impact on electrical quality factor $Q_{elec}$.