A High Isolation Dual-polarized Antenna with Low Profile Using Partially Reflective Surface

A novel dual-polarized broadband antenna with high isolation and a low profile based on a partial reflective surface is proposed for base station applications. The antenna consists of four pairs of crossed dual-polarized bowtie dipoles which are printed on the top and bottom of the substrate and a partial reflective surface. The bowtie dipole antenna is excited through a balun, resulting in good impedance matching and a radiation pattern with ±45° polarization. By adopting a partially reflective surface (PRS) with negative reflection phase on the top of the dipole antenna. The overall height of the antenna together with PRS can be reduced to 0.174λ
o
(λ
0
is the vacuum wavelength at 4GHz), the port isolation can be improved from 30 dB to 38.5 dB. After loading the PRS above the antenna, the radiator can maintain the impedance bandwidth and a high gain can also be achieved, even if it is close to the reflector. Simulated results demonstrate that the antenna impedance bandwidth for S
11
< 10 dB are 3.24-5.04 GHz (43%), covering the 5G frequency bands in China (n77/n78/n79) and the port isolation is above 38.5 dB over the whole frequency band. The half power beamwidth (HPBW) over the operating bands ranges from 60
^°
to 67
^°
, while the realized gain ranges from 7.3 to 8.9 dBi.