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 TE01δand TM01δmodes in a single cylindrical dielectric resonator (DR). Due to the high Q-factor of the TE01δmode, 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.