Broadband dual-polarized antenna array with enhanced radiation pattern stability

In this paper, a broadband dual-polarized antenna array with stable radiation pattern is proposed for 5 G base station applications. The proposed antenna array consists of a 2 x 2planarantennaarray, four 2 x 2 circle patch parasitic structures and a metal reflector. Based on the principal of the FP (Fabry-Perot) antenna to achieve the stable radiation pattern, when the parasitic loading height meets the resonant height of the FP antenna, serious radiation pattern distortion in large reflector environment could be improved effectively. A prototype of the 2 x 2 broadband dual-polarized antenna array is designed and fabricated. The measured results show that the -10 dB bandwidth of the proposed broadband dual-polarized array is able to cover 3.23-5.06 GHz with high isolation which is greater than 25 dB over the entire operating band. The antenna elementsofthearrayarecapableofmaintainingstable radiation pattern throughout the operating frequency range. The HPBW (half-power beam-width) in the horizontal plane is effectively controlled at 67 degrees +/- 5 degrees with a gain of 8.8 +/- 0.5 dBi. Due to the stable radiation performance mentioned above, the proposed dual-polarized array can be applied to future 5 G and sub-6 G base station applications.