Wave propagation in structures of film bulk acoustic resonators with dielectric loss

摘要

Dielectric loss is inevitable for many piezoelectric materials and it will lead to the dissipation of energy for wave motion. In this paper, we study wave propagation in piezoelectric layered structure of the thin film bulk acoustic resonator (FBAR) with dielectric loss. When the dielectric loss is considered, dielectric constants are complex and the waves are damped which means wavenumber is complex. Thus, the dispersion equations were derived first, and then three dimensional dispersion curves were given in the range of real frequency and complex wavenumber. Further analyses on the characteristics of the wave were made based on the 3D dispersion curves, and the attenuation of the wave was shown. A comparison with the results obtained from the model without dielectric loss was also discussed.