Investigation of Electromechanical Coupling and Quality Factor of X-Cut Lithium Niobate Laterally Vibrating Resonators Operating Around 400 MHz

In this paper we present laterally vibrating resonators (LVRs) based on X-cut lithium niobate (LN) exhibiting a maximum quality factor (Q) around 1200 and an electromechanical coupling (kt2) of 30%. This paper shows how the highest kt2ever attained in X-cut LN resonators can be combined with very high Q to achieve a resonator figure of merit (FoM = kt2· Q) of 360. In this paper, we validate the theoretical prediction of kt2versus the resonator orientation in the YZ plane and investigate what geometrical parameters mostly impact the Q of these devices.