A Broadband Dual-Polarized Omnidirectional Antenna Based on Orthogonal Dipoles

A broadband dual-polarized omnidirectional antenna is investigated. The proposed dually polarized antenna consists of four vertical dipoles for vertical polarization (VP) and four horizontal dipoles for horizontal polarization (HP), which are uniformly printed around a dielectric cylindrical barrel for omnidirectional radiation. Two broadband feeding networks are employed to excite the vertical dipoles and the horizontal dipoles, respectively. The dual-polarized omnidirectional antenna achieves a bandwidth of ~ 30% (1.7-2.3 GHz) with an isolation of about 25 dB. The gain variations in the horizontal plane are less than 0.5 dB for VP and 1.5 dB for HP. The cross-polarization levels of VP and HP in horizontal plane are around -20 dB. The proposed antenna has a great potential for mobile communications.