Outdoor Wi-Fi Dual-band Dual-polarized Base Station Antenna Design

In this manuscript, a dual-band and dual-polarized coupled patch array antenna operating at 2.45 GHz and 5.8 GHz for outdoor Wi-Fi applications is proposed. Two sets of antenna arrays made of four-element stacked patches act as main radiators. The height of this antenna is 0.04λ0, which is much smaller than the general size of other low-profile antennas. The arrays are fed by two feed ports which are used to separately feed vertical and horizontally polarized signals with stable port isolation. The antenna structure also employs a duplex filter to filter 2.4-2.484 GHz and 5.1-5.9 GHz operating band frequencies. The measured impedance bandwidths of the prototype antenna structure are 2.41-2.484 GHz and 5.1-5.9 GHz, respectively. The isolation between the two ports is greater than 20 dB, and the cross-polarization level is better than 20 dB in the operating bands. In addition, the average gain of the prototype antenna is approximately 13 dBi in horizontal and vertical polarization. Overall, because of the stable structure, high reliability, small size, and light weight of the patch antenna, the outdoor base station antenna has a huge potential market value, this antenna is a good candidate for commercial outdoor Wi-Fi applications.