Study of Thin Film LiNbO<sub>3</sub> Laterally Excited Bulk Acoustic Resonators
Soumya Yandrapalli, Seniz Esra Kucuk Eroglu, V.P. Plessky, Hüseyin Baris Atakan, Luis Guillermo Villanueva
Abstract
This work presents an in-depth study of simulation and measurement results of laterally excited shear bulk acoustic resonators (XBAR) in Lithium Niobate, at 5 GHz with high electromechanical coupling factor (<inline-formula> <tex-math notation="LaTeX">$k_{t}^{2}$ </tex-math></inline-formula>) as high as 25%, and with impedances at resonance close to <inline-formula> <tex-math notation="LaTeX">$2~\Omega $ </tex-math></inline-formula>. Loaded Quality factors of up to 340 and 150 are obtained at resonance and anti-resonance, respectively. Experimental00 dispersion behaviors of main mode and spurious are presented. Several geometric parameters affecting resonator performance are studied in order to improve figure of merits (FoM) of the device for 5G filter applications. The modified fabrication process presented shows a high yield of over 90% of devices which can be scalable for mass production of high frequency, sub-6 GHz, wide band filters. [2021-0202]