Circuit modeling of Surface Acoustic Wave (SAW) resonator with circular geometry

Abstract

Surface Acoustic Wave (SAW) devices play an important role in telecommunication systems and are widely used as electronic filters, resonators, actuators and oscillator. SAW resonator consists of metallic structures of interdigitated transducer (IDT) deposited on piezoelectric substrate. The geometry of IDT will affect the resonator's characteristic. There are several methods for modeling and analysing SAW devices include the impulse model, the equivalent circuit model, the coupling-of-mode (COM) model and matrix model. This project focused on the modeling of circular SAW resonator using equivalent circuit technique. Curve fitting between the lumped element circuit and S11 measurement of two resonator designs was demonstrated using AWR Design Environment software. Based on the results, it shows that the frequency response from the equivalent circuit model agrees well with experimental measurement of each device. This project comes out with the optimum equivalent circuit that is suitable for circular SAW resonator.