Phononic SAW transducers with complete frequency bandgap characteristics

Abstract

2D composite grating building blocks with hexagonal symmetry are proposed and analyzed as efficient reflectors and transducers in the design of low loss surface acoustic wave (SAW) resonators. Eigen-frequency and frequency response finite element analyses (FEA) are used to study the propagation and excitation characteristics of SAWs in the 2D composite structures. The proposed structures have the advantage of being compatible with the planar SAW technology, while exhibiting a complete frequency bandgap. Three distinct types SAW phononic transducers are here invented and their operation confirmed both analytically and experimentally. The proposed research paves the way for subsequent implementation of the phononic bandgap technology in high performance micro-acoustic RF components.