Wideband dual-polarized crossed bowtie dipole antenna with shorted stubs for base station applications

Abstract

A wideband dual-polarized crossed-dipole antenna with shorted stubs for base station applications is presented. By using a pair of orthogonal crossed-dipole, two linear polarizations (± 45°) are obtained. The shorted subs are introduced to improve the impendence bandwidth and enhance the isolation (S₁₂) between the two orthogonal polarizations. The antenna shows a wideband impedance characteristics of about 29.4% for S₁₁≤-10 dB (+45° polarization) and S₂₂≤ -10 dB (-45° polarization). High isolation(S₁₂≤ -32 dB) between the two polarizations in the required band is obtained, which the lowest isolation is only -56 dB at about 1.8 GHz. The stable peak gain, unidirectional radiation patterns, low cross-polarization and high front-to-back ratio over the whole operating band are also achieved. Due to its good performance, the antenna is very suitable for potential base station applications in mobile communication such as DCS, PCS and UMTS.