A Low-profile Wideband Dielectric Resonator Antenna Suitable for Beam-forming Applications

Recently some interesting low-profile DRA designs, known as dense dielectric patch antenna and planar dielectric antenna, are proposed to solve DRA’s bulky and positioning issues. However, these designs either have large planar sizes $(\gt 0.5h^{\ast}0.5h)$ or have narrow bandwidths (<10%), limiting their applications. In this paper, a low-profile wideband dielectric resonator antenna (DRA) with very compact planar size is investigated. The antenna consists of a high permittivity dielectric sheet on the top, a low permittivity substrate in the middle and a slot feeding structure in the bottom. The antenna planar size is set as $0.35\lambda_{0}^{\ast}0.35\lambda_{0}$ that is suitable for beam-forming applications. By slightly increasing the height of the marginal parts of dielectric sheet, the high order TE
131
mode can be shifted down to combine with the dominant TE
ll1
mode, yielding a wide bandwidth. With this structure, the antenna can obtain a 10-dB impedance bandwidth of 18.5%, and a peak gain of 7.3 dBi with a low-profile of 0.08$\lambda_{0}$.