Analysis and design of UWB monopole-dielectric resonator antenna

In this paper, an improved hybrid antenna comprising of a quarter-wave monopole and a dielectric-resonator antenna of two cylindrical cavities is proposed, optimized, designed, fabricated and measured. Through the physical insight of antenna properties via the surface current distributions along the monopole and also the E-field vector distributions inside the dielectric-resonator antenna configuration, it is observed that at the lower frequencies, the improved hybrid antenna behave like a conventional monopole antenna; at middle frequencies, the mutual coupling of the monopole and the dielectric-resonator with two cylindrical cavities turns to be stronger, and at the higher frequencies, such a mutual coupling becomes the maximum and the majority of the power is radiated from the inside of the improved hybrid dielectric-resonator antenna. The antenna is found to exhibit the ultra-wide bandwidth and its gain is over 4 dB at higher frequencies.