An efficient analysis of thin-film bulk acoustic wave resonators using FDTD method with ADI time-marching scheme

For an efficient time-domain modeling of thin-film bulk acoustic wave resonators (TFBARs), a unconditionally stable finite-difference time-domain method based on the alternating direction implicit scheme (ADI-FDTD) is introduced to the analysis of a typical TFBAR structure. Because the time step size in ADI-FDTD is free from the stability constraint, this method is very useful to analyze electromechanical phenomena of TFBARs having fine geometrical variations, which is a challenging problem to conventional FDTD modeling. To validate the proposed scheme, the impedance characteristics are obtained by the proposed method and compared with the traditional FDTD results and the analytical solutions.