Two-dimensional Electromagnetic Periodic Structure Theory And Applied Research

The dissertation research three aspects as follows:1. Theoretical modeling and analysis of high impedance surface and their application. The dissertation simplifies high impedance, gives a equivalent model, and uses transmission line method to explain the resonance of high impedance. Then based on this theoretical model, the dissertation gives a structure of high impedance surface which is not uniform. Finally applies this structure in antenna, and gives a example of rectangular patch antenna. From the example, it can be observed that the high impedance surface can restrain the backwards radiation.2. Studies on a kind of wave absorber which is loading impedance. Recently, a new structure of wave absorber is brought forward which is constructed of FSS loading diodes. The dissertation qualitatively analyses this structure. By simulating, observes the absorbing ability of this structure from its RCS characteristics. Then, dissertation brings forwards a new structure and observes its characteristic by stimulation. The simulation results show this structure has a wide absorbing width and can be controlled.3. Application of FDTD and genetic algorithm in optimization of this kind of wave absorber. The dissertation describes characteristics of the structure in stimulation. Compared PEC PMC method with periodic boundary method. Basing on these, writes stimulation program for the wave absorber of bowtie patch array loading resistance, and computes its reflectance. Then, adds genetic algorithm to stimulation program, writs optimization program.