Analysis of a Slot-Coupled Two-Layer Hemispherical Dielectric Resonator Antenna with Air-gap

In this work, a microstrip slot-coupled two-layer hemispherical dielectric resonator antenna (DRA) with an air-gap between two dielectric layers is analyzed, that is particularly relevant to the design of multilayer DRA configurations. The Green’s function for the structure is formulated using the generalized reflection coefficient. The variation of the TE111 mode resonant frequency and Q-factor with the air-gap for the configuration is investigated. The effect of the air-gap on the input impedance / reflection coefficient along with radiation characteristics for the antenna configuration are also analyzed.