Wideband Horizontally Polarized Omnidirectional Antenna With Small Size

摘要

A compact wideband horizontally polarized (HP) omnidirectional antenna is proposed. To generate HP omnidirectional radiation pattern, four wideband dipoles are employed and connected by a wideband 1-to-4 power divider with equal magnitude and phase, conducting as a loop antenna. Four pairs of parasitic strips placed above the dipoles are used to enhance the impedance bandwidth. To minimize the antenna size, the dipoles and strips are arranged around the perimeter of a small square box and the 1-to-4 power divider is arranged around the bottom of the box. The antenna obtains wide 10 dB return loss bandwidth of 62.1% (1.64-3.12 GHz), good omnidirectional radiation pattern with low gain variation less than 1.3 dBi, small size of 66 mm x 66 mm x 16 mm.