Novel planar wideband omni-directional quasi log-periodic antenna

In this paper, a novel and simple wideband planar omni-directional antenna is proposed. The simultaneously wideband and omni-directional characteristics of the proposed structure are achieved by adding two mutually-coupled elements to the conventional dipole antenna. This newly proposed structure is able to extend the bandwidth (VSWR/spl les/ 2:1, at UHF band) to 30% compared to simple dipole antennas while maintaining an omni-directional radiation pattern with maximum gain of 2.2dBi.