Transmission Line Matrix (TLM) modeling of 1D phononic crystals

D, Lakhel; A, Saidane

Communication science et technologie
Volume 13, Numéro 1, Pages 01-14
2015-01-01

Transmission Line Matrix (tlm) Modeling Of 1d Phononic Crystals

Abstract

Abstract: In this paper an acoustic Transmission Line Matrix (TLM) method for the calculation of phononic band gaps is presented. It is applied to the study of 1D propagation of longitudinal waves in a MEMS Silicon thin structure. The system is modeled as a series of acoustic transmission lines with different characteristic impedances representing the two phononic materials with different Young’s modulus and mass density. The phononic band gap predicted by this model is verified against FEM results. Further application of the model to the design of 1D phononic crystals shows that increasing the holes length lx of phononic crystal shifts the band gap towards lower frequencies. The broadening effect of band gaps was related to the filling factor. This broadening was found to reach it maximum when the lattice constant of the two phononic crystals are the same.