Lithium niobate lateral overtone resonators for low power frequency-hopping applications

This work reports the first lithium niobate (LiNbO3) lateral overtone bulk acoustic resonator (LOBAR) with a high figure-of-merit (FoM) for each overtone. We exploit electrode offset as a key parameter to excite both the even-order and the odd-order modes with uniform kt2. The fabricated device shows Qs (1966, 1215, and 1513) among the highest reported for LiNbO3 resonators at the equally-spaced resonances (446.4, 599.8, and 757.3 MHz). As a result, high FoMs of 83.6, 102.6 and 63.1 have been obtained simultaneously for aforementioned resonances. These FoMs significantly surpass those of the state-of-the-art overtone devices. With these qualities, frequency-hopping oscillators based on LiNbO3 LOBARs can be enabled for low power and phase-continuous frequency-hopping applications.