Research Of Photonic Crystals And Its Application On Microwave Filter

The research on photonic crystals has become a hotspot of assignment in the world from its naissance in the 1980s and the application research of the photonic crystals is brilliant and huge. Photonic crystal is a new kind of materials with periodic property dielectric structure. The essential physical characteristic of photonic crystal is that the material has photonic band-gap (PBG). The material has many other unique properties such as periodic structure, photonic localization, polarization etc. The general equation of photonic crystal is Maxwell Equation Groups. We study the equation by the method of plane wave or green ruction of FDTD (Finite difference of time domain)or transfer matrix. The photonic crystal will has been used in many area, such as photonic crystal microwave antenna, photonic crystal micro strip photonic crystal microwave resonator etc. The fabrication and application research of photonic crystal also has become an important assignment research in academic circles. At present, we fabricate photonic crystal by methods such as layer of layer, addition, drilling, three dimensional etching, mechanical technique, optical, colloid, anti opal. In this paper we analyze the band-gap structure and characteristic of photonic crystals, introduce the theory of PBG filter. The theory and characteristic of FDTD method are also introduced. Emphatically we refer to the appliance of PBG in the microwave field. FDTD method, together with perfectly matched layer (PML) technique as absorbing boundary condition (ABC), is applied to design and analyze PBG filters in the paper. With the help of the software of FDTD and Mat lab tools, we design a kind of H-shape PBG filter, and pick up the S parameter. The extrapolation technique is used to deal with the result. The technique raises the computing efficiency, optimizes the process of the design, and gets rid of the vibration of the S parameter curve.