A Fast Approach for the Structural Design of Frame-Like Fbar Based on 2d Plate Theory

In recent years, film bulk acoustic wave resonators (FBARs) have been successfully utilized in almost every wireless system due to their good performance. To optimize the working performance of FBAR, frame-like structure was previously proposed to suppress the resonances of so-called spurious modes. Another aspect that has impact on the working performance of FBAR is the undesired coupling modes, which were rarely studied due to the lack of proper theoretical tools. In this paper, a fast approach for the structural design of frame-like FBARs is proposed with the use of two-dimensional plate theory. The widely used state-vector approach is applied here and both free and forced vibration results are obtained. The structure size of frame-like FBAR is determined through the analysis of frequency spectra and the results are compared with those obtained with 3D FEM software to ensure the accuracy of our proposed method. Mode shapes and admittance response curves show the suppression ability of spurious modes and the undesired coupling modes in the designed frame-like structure. Results in this paper show that the presented method can work as an effective tool in engineering design process.