Design of a loop patch antenna system with improved bandwidth for 2.4-GHz WLAN applications

In this work, a design for enhancing impedance bandwidth of a dual-polarized loop patch antenna system for 2.4 GHz WLAN applications is proposed and tested. The designed antenna is a modified form of the circular loop patch antenna system consisting of three identical loop antennas printed on an FR-4 substrate. The loops on the patch are arranged in a symmetrical multi-antenna structure. By incorporating two slots in each loop, the impedance bandwidth of the antenna is improved by 5.3%. Measured results showed that the proposed antenna system offers a peak gain of about 8 dBi, the -10-dB return loss bandwidth of 11.9%, and the isolation between ports below -20 dB in the required frequency band. This antenna is expected to be suitable for 2.4 GHz wireless access points with 3×3 multiple-input multiple-output (MIMO) antenna systems.