Patch microstrip antenna with improving radiation performance for 2.4-GHz WLAN access point

A patch microstrip antenna with an inverted-V ground plane capable of improving radiation performance for a wireless local area network (WLAN) access point in the 2.4-GHz band is presented. By using a feeding structure composed of a step-shaped feeding strip in the air substrate and a coplanar strip in the narrow radiating patch, the proposed antenna can reduce cross-polarisation radiation (less than -20-dB) for frequencies across the 2.4-GHz WLAN band. The inverted-V ground plane comprises a narrow central ground portion for setting the 50 subminiature version (SMA) connector for the patch antenna and two bent ground portions to control the broadening of the antenna s horizontal radiation pattern. By selecting the proper dimensions, the proposed antenna can have a wide horizontal radiation pattern of about 152 (3 dB beamwidth) with vertical polarisation, which is very suitable for WLAN access-point applications where uniform radiation in one direction or one half-space is required. Experimental results of a constructed prototype suitable for application in the 2.4 GHz WLAN access point are presented and discussed.