A novel dual-polarized broadband planar antenna for base stations

A new dual-polarized broadband planar antenna is proposed for 2G/3G/4G (LTE) base stations. The dual-polarized planar antenna is made up of two orthogonally crossed double-dipoles. Each double-dipole is composed of a pair of dipoles and directly fed by a short 50-Ω microstrip line. The double-dipoles and the short microstrip lines are printed on a single substrate, making the dual-polarized antenna planar and compact. It is shown that the dual-polarized planar antenna has a bandwidth of 51% (1.61-2.71 GHz) for return loss >15 dB and an isolation of higher than 30 dB. A half-power beamwidth (HPBW) of around 65° for slant ±45° polarizations is obtained over the frequency band from 1.7-2.7 GHz. The average gain of the dual-polarized antenna is 9 dBi.