The Study And Application Of Wave Concept Iterative Procedure In Microwave Planer Circuit

With the rapid development of microwave circuit, various kinds of numerical methods for electromagnetic field analysis are also developed to accommodate with it. But most traditional methods, such as MOM, FEM and FDTD, need a large memory requirements and long computation. In this paper, the wave concept iterative procedure (WCIP), based on transformation between spatial domain and spectral domain, is introduced. In this method, the discontinuity plane of microwave circuit is divided into small rectangular cells. Iterative relationship of wave sources and reflected waves is created on the plane. The Fast Fourier Mode Transform is used, which avoids the selection of base function and inverse conversion of large matrix, saves some memory, and improves computing speed effectively. The work of this dissertation is as follows:On the one hand, in this paper, the principle of the wave concept iterative procedure is described. The expression form of spatial diffraction operation is further concluded. The spatial diffraction operation is derived under the multiple port networks. The principle of the WCIP for FSS of periodic structure is studied. The operation's number is compared between WCIP and the traditional algorithm, which verifies the efficiency of this method.On the other hand, the microwave planer circuit is analyzed by using the WCIP, which verifies the correctness and efficiency of the WCIP, expands the use of this method. Firstly, Microstrip patch antenna is analyzed. The fields distribution of the patch surface is simulated, the return loss and VSWR of Microstrip patch antenna are solved. Then an H-shaped patch antenna and slot-loaded H-shaped dual-frequency antenna are studied, satisfactory results are achieved. Secondly, the Microstrip filter is studied and S parameter of the open loop resonator band-pass filter is calculated. Ultimately, the WCIP is extended to analysis the frequency selective surfaces (FSS). By calculate the characteristics of one cell, combining with the law of periodic structure, the characteristics of whole FSS circuit are analyzed, which simplifies the process and enhance the efficiency of analysis. By changing the relevant parameters, the frequency response of FSS transmission coefficient are obtained.