Trilayer Periodically Poled Piezoelectric Film Lithium Niobate Resonator

This work presents the first demonstration of a three layer periodically poled piezoelectric film (P3F) lithium niobate resonator. The proposed platform allows for high series 3dB quality factor (Q) resonances, including Q up to 811 at 12.98 GHz. The trilayer film stack employs the use of three lithium niobate layers with alternating orientations on an intermediate amorphous bonding layer and sapphire substrate. This trilayer platform enables the use of high order Lamb modes with high Q thanks to the comparatively large thickness of the film when compared to monolayer counterparts. The platform shows ultra high $f\dot Q$ product up to 1.4 × 10¹³ at 25.96 GHz, in line with the state of the art. This work demonstrates the potential for further improvement in mm-Wave acoustic resonators and devices through the maturation of P3F designs.