High-performance Love-mode phononic crystal resonators on LiNbO3/SiC achieving an FoM of 352

This Letter reports a high-performance Love-mode phononic crystal resonator (PnCR) on a LiNbO3/SiC substrate, realized by substituting conventional Bragg reflectors with phononic crystals (PnCs). This approach significantly enhances energy confinement, achieving a record figure of merit (FoM) of 352.4, currently the highest reported in thin-film surface acoustic wave (TF-SAW) devices, along with an electromechanical coupling coefficient (kt2) of 27.3% and a maximum Bode-Q (Qmax) of 1291 at 2.18 GHz. Additionally, a periodic dependence of Qmax on the spacing between PnCs and the interdigital transducers provides a valuable design guideline. These results underscore the transformative potential of PnCRs in advancing next-generation microwave acoustic devices toward higher performance and greater miniaturization.