Omnidirectional Cylindrical Dielectric Resonator Antenna With Dual Polarization

This letter proposes an annular cylindrical dielectric resonator antenna (DRA) with two-port diversity realizing simultaneously omnidirectional horizontally and vertically polarized radiation patterns with low cross coupling. The horizontally and vertically polarized radiation patterns are achieved by exciting the orthogonal TE _01δ and TM _01δ modes in a single cylindrical dielectric resonator (DR). Due to the high Q-factor of the TE _01δ mode, an air gap and multiple feeding lines are introduced to increase the impedance bandwidth. The proposed antenna provides an impedance bandwidth of 19.1% in the vertically polarized mode and an overlapping bandwidth of 7.4% in the horizontally polarized mode, with the overlapping band ranging from 3.78 to 4.07 GHz. Antenna diversity and multiple-input-multiple-output (MIMO) performance are examined in terms of envelope correlation coefficient and mean effective gain.