Integrated, single-feed, dual-polarized loop antenna for compact, outdoor access-point applications

A printed loop antenna for integration into a compact, outdoor WLAN access point (AP) is presented. The loop design has a one-wavelength, resonant structure with respect to the centre operating frequency of the 2.4 GHz band and is formed on a 1.6-mm thick FR4 substrate. The antenna substrate is further stacked above a system PCB of an outdoor AP by a small distance. In this study, the proposed design integrates the system printed circuit board (PCB) serving as an efficient reflector for the loop into an internal AP antenna solution. The results showed that by feeding the proposed square loop at one corner and adding the tuning portion at the diagonal corner, the dual-polarized radiation in the two major planes and good impedance matching can be attained. High gain, directional radiation patterns were also obtained.