Laterally-excited bulk-wave resonators (XBARs) with embedded electrodes in 149.5° Z-cut LiNbO3

In this paper, we present a new design of laterally-excited bulk wave resonators (XBARs) which contains narrow embedded interdigital electrodes (IDEs). The proposed XBAR has a high electromechanical coupling coefficient (K _eff ² ) of 33.51 % and the smooth impedance curve. With the assistance of 149.5° Z-cut lithium niobate (LiNbO ₃ ) in XBARs, we obtain a high K _eff ² of 42.54%. We investigate the impact on K _eff ² and spurious modes of XBARs with different depths of electrodes Te). XBARs with the optimization of embedded electrodes show a great prospect in fabricating broad bandwidth filters.