多杯圆形辐射器方向图分析计算

Analysis of Multi-Groove Circular Radiators with Moment Method

利用矩量法和几何绕射理论 (GTD)分析计算多杯多模圆形辐射器的辐射场 .辐射器中心波导为圆波导 ,由TE1 1 模激励 ,带有若干个同轴杯 .首先利用等效原理和矩量法计算嵌在无限大金属板上圆形辐射器的等效磁流分布 ,允许各波导区域中有任意多个高次模式存在 ,利用傅里叶变换法求得其辐射方向图 ,然后把该辐射场作为有限圆形接地板边缘的入射场 ,利用GTD计算圆接地板边缘对辐射器方向图的贡献 .具体分析了三杯圆形辐射器的方向图 。

The method of moments was employed, in conjunction with the equivalent-source technique and the modal expansion theory, to analyze multi-groove and multi-mode circular radiators. No restriction was imposed on the number, width and depth of grooves, so the theoretical method and the analytical formulation are applicable to the analysis and design of wide-ranging coaxial grooved radiators. The problem of radiation from a multi-groove and multi-mode circular radiator embedded in an infinite ground plane was solved first. Then, expressions representing the elevation-plane patterns of the radiator embedded in a finite ground plane was derived using Geometrical Theory of Diffraction (GTD). The expressions for the field pattern were obtained by superposing the infinite ground plane solutions, the first-order diffracted field solutions and the axial caustic solutions in their respective regions of validity. The calculation results are in agreement with experiment measurements.