Effect of fabrication imperfections for ground-plane-backed dielectric resonator antennas with coaxial excitation

The effect of imperfections in terms of surface roughness which could lead to the introduction of air gaps between the dielectric resonator (DR) and the contacting conducting surfaces is investigated. Results of studies which illustrate the effect of air gaps upon the input impedance and resonant frequency of cylindrical dielectric resonator antennas (CDRAs) operating in the TM
01
and HEM
11
modes are presented.