A Systematic Approach to the Analysis of Spherical Multilayer Structures and its Applications
This work presents a generalized approach to analyze radial waveguides, dielectric resonators, dielectric resonator antennas and microstrip antennas on spherical multilayer structures. It aims at the applicability to any type of spherical closed and sector structures, which also include hemispherical ones. Additionally, arbitrary layers may be air or dielectric substrates with or without metallizations in the interfaces and the inner layer may be a metallic or dielectric core. The applicability of this approach is demonstrated by applying it to some radial waveguides, dielectric resonators and microstrip antennas. The system equation or Dyadic Green's functions of test structures are analytically exact with literature. Numerical results are verified either with commercial software codes or measurement data. The effects of curvature and the ground plane on the input impedance and radiation pattern are also shown. The developed approach also allows the determination of the resonant frequency, radial propagation constant for possible resonant modes of radial waveguides, dielectric resonators, and characteristics of microstrip antennas on spherical multilayer structures. Recently, this work has been combined with previous works on planar and cylindrical structures to be a generalized procedure to set up the dyadic Green's function of multilayer structures, which is applicable to rectangular, cylindrical, and spherical coordinates.