High $Q$ Antisymmetric Mode Lithium Niobate MEMS Resonators With Spurious Mitigation

This paper reports on the demonstrations of first-order antisymmetric Lamb wave (A1) mode resonator as a new platform for front-end filtering of the fifth-generation (5G) wireless communication. The sub-6 GHz resonance in this work is achieved by employing the A1 mode in the micromachined V-cut Lithium Niobate (LiNbO
₃
) thin films. The spurious modes mitigation is achieved by optimizing the distribution of the electric field. The demonstrated figure-of-merit (FoM = Q · k
²
_t
) of 435 marks the first time that a new resonator technology with the FoMs exceeds those of surface acoustic wave (SAW) resonators and thin-film bulk acoustic resonators (FBARs) in the sub-6 GHz (1-6 GHz) frequency range.