Design of hybrid ultra-wideband monocone-dielectric resonator antennas with different load materials

A hybrid of a monocone antenna and a dielectric resonator antenna structure is designed with different values of permittivity of the dielectric resonator. The designs without extra matching circuitry are obtained through fully automated optimization of the antenna structure with input reflection coefficient in the 50 ohm environment as the objective over the 2-to-8 GHz band. Designs with the open cone and closed cone are also compared and they perform quite closely in terms of the reflection coefficient and the radiation figures. An important outcome, compared to the previous work on this type of antennas where the final designs were prototyped using foam dielectric loads (with relative permittivity less than two), is that the presented design example can be implemented with solid commercially available high-frequency dielectric materials. The design examples are provides for the relative permittivity values of 2.1, 4.5, and 6.0.