Analysis of the relationship between the properties of line defect waveguide and the distribution of displacement vector within band gaps of the phononic crystal

This paper has analyzed the relationship between the distribution of displacement vectors and the properties of corresponding line defect waveguide within the band gaps of PCs. In order to obtain the band gaps of PCs, a delay line model was built. Through simulating this model by finite element method, the displacement vectors in PCs also can be obtained. To analyze the properties of corresponding line defect waveguide, the model of line defect waveguide has been built and calculated. With this method, a PCs consisting of 128°YX lithium niobate matrix with cylindrical hole from a square lattice is analyzed. The results show that the SAW displacement vector in the propagation direction decrease slowly and the SAW displacement vector in the transverse direction is large relatively, it will have a good property of line defect waveguide.