Analysis of radiation from a line source in periodic cylindrical structures

A semi-analytical method for analyzing electromagnetic radiation from a source located in a cylindrical structure composed of circular rods periodically distributed along concentrically layered circular rings is presented. The method uses T-matrix of a circular rod in isolation, the reflection and transmission matrices of a cylindrical array expressed in terms of the cylindrical harmonic waves as the basis. The advantage of the method is simplicity and efficiency in computation. Radiation pattern of a line source located inside the periodic cylindrical structure is numerically studied.