Analysis of the dielectric disc antennas above a grounded dielectric substrate

A radiating structure called a circular microscope antenna, made of dielectric resonator disk, is considered. The antenna structure has a dielectric disk with a high dielectric constant mounted on top of a grounded dielectric substrate that has lower dielectric constant. A coaxial probe simulated by an electric dipole is used for exciting the antenna. The HEM/sub 11/ mode is excited by exciting the antenna at the resonant frequency of the HEM/sub 11/ mode and placing the electric dipole very close to the edge of the dielectric disk. The effects of different parameters on the radiation patterns, resonant frequencies, and radiation Q-factor of the antenna are studied. The frequency decreases as the permittivity increases. The radiation Q-factor of the antenna, on the other hand, increases as the permittivity increases. However, one can see that the radiation Q-factor is low, which suggests that the antenna will be a good radiator if the HEM/sub 11/ mode is excited. It also suggests that this antenna will be a broadband type of antenna compared to the microstrip antenna.<>