A high gain circularly polarized (cp) antenna array using sequential phase (sp) rotation technique for wlan applications

This paper designs and investigates a high gain circularly polarized 2 × 2 antenna array for wireless applications using the sequential phase rotation technique. The feed network utilizes four rectangular lines of equal width and three 90° arcs. The length of all elements is equal to λ_g/4 to provide 0°, 90°, 180°, and 270° phase differences at the four outputs of feed network to increase the axial ratio(AR) bandwidth and purity. Four corner truncated patch elements are connected to the feed network to fulfill the 2 × 2 antenna array design. The proposed design operates with an impedance bandwidth of 1.1 GHz from 4.9 GHz to 6 GHz bandwith and an AR bandwidth of 0.8 GHz from 5 GHz to 5.8 GHz band. The maximum measured gain of the antenna array is observed as 8.9 dBic in the operating band. The antenna array was prototyped and tested to validate its performance. This array is well suitable for high gain WLAN applications.