WIDEBAND DUAL-POLARIZED DIPOLE ANTENNA WITH DIFFERENTIAL FEEDS

A wideband dual-polarized dipole antenna is presented using the differential feed technique. The proposed antenna consists of two horizontal bow-tie dipoles and four vertically oriented meandering strips. Two pairs of differential-fed L-shaped microstrip feed lines are used to excite the antenna. Due to the differential-fed technique, the cross polarization level can be reduced to −35 dB. With the introduction of the meandering strips connecting the radiating patch to the ground plane, the height of the antenna is about 0.102λ0. A parametric study is performed to provide information for designing and optimizing such an antenna. The proposed dipole antenna has been fabricated and measured. The impedance bandwidth of 48.3% (S11 < −10 dB) from 2.57 GHz to 4.21 GHz is achieved. The measured isolation between the feeding ports is better than 30 dB over the operating band. Moreover, the antenna has a compact structure and good unidirectional radiation pattern, making it conveniently integrated with microwave differential circuits and applied in the base station systems.