Tunable Electromechanical Coupling Coefficient of a Laterally Excited Bulk Wave Resonator with Composite Piezoelectric Film

A resonator with an appropriate electromechanical coupling coefficient ([Formula: see text]) is crucial for filter applications in radio communication. In this paper, we present an effective method to tune the [Formula: see text] of resonators by introducing different materials into a lithium niobate (LiNbO(3)) piezoelectric matrix. The effective piezoelectric coefficients [Formula: see text] and [Formula: see text] of composite materials with four different introduced materials were calculated. The results show that the [Formula: see text] of SiO(2)/LiNbO(3) composite piezoelectric material was mostly sensitive to an increase in the width of introduced SiO(2) material. Simultaneously, the simulation of a laterally excited bulk wave resonator (XBAR) with SiO(2)/LiNbO(3) composite material was also carried out to verify the change in the [Formula: see text] originating from the variation in [Formula: see text]. The achievable n79 filter using the SiO(2)/LiNbO(3) composite material demonstrates the promising prospects of tuning [Formula: see text] by introducing different materials into a LiNbO(3) piezoelectric matrix.