GHz voltage amplification in a stack of piezoelectric ScAlN and non-piezoelectric SiO₂ layers

Abstract GHz voltage amplification was found in a stacked structure of piezoelectric layers (such as ScAlN) and non-piezoelectric layers (such as SiO 2 ). This allows for large-area fabrication using commercial equipment. This approach contributes to wireless sensor activation. The electromechanical coupling coefficients k t 2 of the input and output layers were found to be 17.6% and 13.7%, respectively. An experimental open-circuit voltage gain of 4.5 (+13 dB) at 0.8 GHz was observed, with a maximum transmission loss (S 21 ) of −5 dB. The experimental result shows good agreement with the theoretical prediction simulated by the electromechanical transmission line model.