Compact high‐gain printed loop‐antenna array integrated into a 5‐GHz WLAN access point

A printed, planar loop‐antenna array having a compact structure and high‐gain, directional radiation properties for WLAN operation in the 5 GHz band is presented. The antenna‐array design is composed of four‐folded loops arranged to be of 2 × 2 configuration, printed on both sides of a 1.6‐mm thick FR4 substrate, and one system printed circuit board (PCB) serving as an efficient reflector for the loops. The antenna array is set within the boundary of the PCB (size of 50 mm ×65 mm) and stacked there above by a separation distance of 5.4 mm only. That's, the design integrates the system PCB of an access point (AP) into an internal antenna solution for compact outdoor AP applications. The results show that good input matching with voltage standing wave ratio (VSWR) below 1.5 over the 5150–5825 MHz band can be achieved. Directional radiation patterns with peak gain at about 10 dBi were also obtained. Details of the antenna design are described and discussed.