介质覆盖导电球上缝隙天线的辐射

Analytic solution of the radiation of slot on electrical sphere coated with dielectric layer

给出了用位函数方法推导介质覆盖导电球上缝隙天线辐射场严格解的过程。基于球Hankel函数加法定理,将基本磁流源激励的场展开为以球心为原点的球面波的叠加。利用球矢量波函数的定义及性质,提取出场的径向分量,将初级场分解为相对于径向的TE波和TM波,避免了复杂的矢量微分运算。在此基础上依据散射叠加原理,构造出各区域中场的一般表示形式,其中待定系数直接由球面分层介质中波的反射和透射规律给出。作为实际应用的例子,给出了介质覆盖导电球上均匀环缝问题的计算结果,并对结果进行了分析。

A novel method based on potential function theory is given in this paper to formulate the analytic solution of slot antenna on electrical sphere coated with dielectric layer. The field excitated by basic magnetic current with arbitrary position and arbitrary orientation is expressed by series of sphere waves whose centers are at the coordinate origin using the addition theorem of sphere Hankel function. Using the definition and character of vector function, the field is separated to TM wave and TE wave relative to r without complex vector-differential operation. Then the problem of radiation of slot antenna in spherically stratified medium is transformed to the reflection and transmission problem of sphere wave on spherical interface. The analytic formulation of fields in every region is given by scattering superposition method, and the coefficients are solved using boundary condition. At last, some calculated results are presented and discussed.