Scattering Calculation Of The Cavity-backed Microstrip Patch Antenna And Radiation Modeling

A cavity-backed microstrip patch antenna is a microstrip patch antenna embedded in or residing on a rectangular cavity-backed filled by anisotropic substrate or aperture field, which not only has the general microstrip antennae's advantage of low cost, low weight and low profile, but also has good function in bandwidth and radiation efficiency. So the study of cavity-backed microstrip patch antennae became very popular in the research of microstrip antennae in recent years.In this paper, analysis start from a variational formulation, based on finite element method (FEM) and use open-region boundary conditions as the core, then use the finite-element-boundary-integral method (FEM-BI) to analyze the scatterance and radiation characteristic of cavity-backed microstrip patch antennae. We use the FEM to solve the Helmholtz equation in the interior of the antenna and use the boundary-integral method to determine the fields exterior to the antenna. We couple the two methods at the interface plane by enforcing the field continuity conditions. The antenna is subdivided into small finite tetrahedral, after choosing appropriate vector basis function to express the electric field the problem can be converted to a matrix equation calculation. When calculate the element electric field, the electric field of the whole region will be readily solved. Radar cross-section (RCS) is an important parameter of a target antenna, to minish RCS is antenna's important development direction all the time. Several numerical results are presented via analyzing the influence of the radar cross-section of the antenna owing to different antennae structure and different medium filled in the cavity, consequently, it can demonstrate the accuracy and validity of this method.