A Novel Hemispherical Dielectric Resonator Antenna With Complementary Split-Ring-Shaped Slots and Resonator for Wideband and Low Cross-Polar Applications

In this paper, a novel hemispherical dielectric resonator antenna (HDRA) with complementary split rings and slots is proposed and investigated. The complementary split-ring resonators (CSRRs) are etched from the ground plane, which are pierced though slots extending from the ground plane up to the HDRA. The dielectric material used is Rogers TMM10, which has a dielectric constant of "r ¼ 9:2. The CSRR-shaped slot on HDRA lowers down the quality factor (Q-factor) of the antenna, thus enhancing the bandwidth. Furthermore, the current distribution across the CSRR slots on the ground plane is out of phase, which results in current cancelation along the CSRR and hence reduces the cross-polar component of the radiation pattern significantly. The measured value of bandwidth of the proposed structure is 30% centered at 1.9 GHz, offering a gain of 6 dBi. The cross-polar level is more than 40 dB, which is much lower than the copolar pattern. The first two modes of the HDRA are preserved.