Abstract
The design of a wideband, vertically polarized omnidirectional dipole antenna based on a non-uniformly segmented structure is presented. The proposed nonuniformly segmented configuration mitigates the phase change of the currents flowing in the long dipole arms, so that the reverse currents which deteriorate the radiation pattern can be avoided, and a stable omnidirectional pattern can be maintained over a wide frequency band. Simulation results show that the proposed dipole has a wide pattern bandwidth of 66%, ranging from 1.96 GHz to 3.90 GHz, with S-11 less than -10 dB. Within the band, the main lobe of the dipole remains in the broadside direction in the E-plane and the antenna achieves the desirable omnidirectional radiation pattern, with a gain flatness of less than 0.3 dB in the H-plane.