Omnidirectional Cylindrical Dielectric Resonator Antenna With Dual Polarization

Abstract—This letter proposes an annular cylindrical dielectric resonator antenna (DRA) with two-port diversity realizing simul-taneously 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 and TM modes in a single cylindrical dielectric resonator (DR). Due to the high-factor of the TE mode, an air gap and multiple feeding lines are introduced to in-crease 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 correla-tion coefficient and mean effective gain. Index Terms—Dielectric resonator antenna (DRA), multifunc-tion, polarization diversity. I