Design and analysis of film bulk acoustic wave resonator in Ku-band frequency for wireless communication

Abstract

This paper presents design of a Film Bulk Acoustic Wave Resonators (FBARs) consisting of piezoelectric film, aluminium nitride (AlN) with top and bottom electrodes of ruthenium (Ru). The lumped Butterworth-Van Dyke (BVD) Circuit model is used to investigate the theoretical harmonic response and extraction equivalent circuit of the FBAR. A three-dimensional (3D) Finite Element Method (FEM) is used to evaluate the electro-mechanical performance of the FBAR. The one-dimension (1D) numerical and the 3D FEM simulation results are analysed and compared. The results show that coupling coefficient (k eff 2) up to 7.0% can be obtained with optimised thickness ratio of electrode/piezoelectric layers. A Figure of Merit (FOM) that considers k eff 2 and quality (Q) factor is used for comparison. The area of FBAR is 900μm 2 and the active filter area size of the FBAR filter is 5400μm 2. The FBAR filter is designed for operation in Kuband with centre frequency of 15.5 GHz and fractional bandwidth of 2.6%. The proposed FBAR filter has insertion loss of -2.3dB which will improve the performance of Ku-band transceiver and improve communication range and data rates in Ku-band communication links.