Impedance Characterization of BAW MEMS Resonators Using RLC (BVD) Equivalent Circuit Model in ADS

Abstract

This paper presents the design and impedance characterization of resonators based on Bulk Acoustic Wave (BAW) Micro-Electro-Mechanical Systems (MEMS) technologies using the Butterworth–Van Dyke (BVD) equivalent RLC circuit model simulated in Keysight Advanced Design System (ADS). The BAW resonator was implemented as a Film Bulk Acoustic Resonator (FBAR) using a piezoelectric zinc oxide (ZnO) thin film and achieved a series resonance frequency of 780 MHz with an S11 return loss of −70.598 dB, demonstrating excellent impedance matching characteristics. The MEMS resonator showed resonant behavior at 1 GHz with a near-ideal S11 value of −100.364 dB and almost lossless transmission performance with S12 ≈ 0 dB. The resonators were analyzed through S-parameter simulations in ADS, and their impedance characteristics were extracted and evaluated to validate resonator performance for high-frequency RF and wireless communication applications. The results validate the effectiveness of the BVD-RLC model for accurate resonator simulation and demonstrate the suitability of the resonators for high-frequency RF filter and sensing applications. Comparative analysis shows that the MEMS resonator outperforms the FBAR-based BAW resonator in terms of resonance sharpness, return loss depth, and overall quality factor.