Investigation Of Characteristics Of Composite Photonic Crystal Patch Antenna

Photonic crystals is a kind of structure which is composed of periodic dielectric or metal materials, it has attracted great attention these years. The surface waves of this structure have band-gap (structure) at some ranges of frequency. The research of PBG structures in microwave region progresses rapidly because of the characteristics of frequency bandgap.The dissertation firstly introduces the fundamental theory and method concerned with Photonic crystals and patch antenna, and then employs the method of FDTD and nonlinear PML to research composite photonic crystal patch antenna in detail. The results obtained show that the performance of the photonic crystal patch antenna designed in this dissertation is improved, for example: reduce the Return Loss, enhance the radiation gain, improve the impedance matching condition, and restrain the high harmonics. The dissertation mainly includes the following contents:(1)A photonic crystal substrate drilling composite patch antenna was designed. As the photonic crystal band gap effect, the antenna substrate surface wave propagation will be restrained, medium base reflector antenna bas疤?n be substantially in the energy, it has a low return loss and high gain.(2)According to the heterojunction theory, the design of a composite photonic crystal heterostructure embedded patch antenna. Compared to ordinary patch antenna, the return loss can be reduced, the gain can be enhanced, futhermore, the antenna's operating bandwidth of the structure has been improved.(3) Through carries on the simulation test of different photonic crystal periodic structure and crystal unit structure of the antenna, the physical property influence of the antenna and some rules of the photonic crystal in the composite patch antenna applications can be generalized.(4) According to the theory of left-hand metamaterial, the periodic aperture resonance loop structure as well as the photonic crystal and the aperture resonance loop neterogeny structure was added into the antenna, the simulation results show that it has the remarkable optimized function to antenna's return loss and the gain.