A Practical Approach: Design of Wideband Cylindrical Dielectric Resonator Antenna With Permittivity Variation in Axial Direction and its Fabrication Using Microwave Laminates

In this article, a practical approach for designing the cylindrical dielectric resonator antenna (CDRA) with permittivity variation in axial direction has been proposed for wideband application. The parametric analysis is performed for designing of homogeneous, two-layer, three-layer, and four-layer multilayer multipermittivity (MLMP) CDRA operating at HE11 delta mode. The effect of antenna parameters, such as the aspect ratio, layers' arrangement, layers' thickness, layers' permittivity, and probe length are investigated. Simulation study shows that if the layers are arranged in ascending order of their permittivities from bottom to top, the bandwidth can be improved significantly with broadside radiation patterns and low cross-polarization levels. The detailed design guidelines are discussed for homogeneous, two-layer, three-layer, and four-layer MLMP CDRA in separate sections. A prototype of three-layer MLMP CDRA is fabricated using commercially available microwave laminates and experimentally verified for input reflection coefficient, radiation pattern, and gain profile. The good agreements between simulation and measured results have been observed. (C) 2013 Wiley Periodicals, Inc.