High isolation, dual-polarized & dual-band single-layer differential MIMO antenna for WiMAX application

In this letter, a dual-band differential CPW-fed MIMO antenna for Worldwide Interoperability for Microwave Access (WiMAX) application is proposed. The antenna has a square ring ground and a common patch which is shared by two pairs of differentially-fed ports. By arranging two pairs of differential ports orthogonally in the virtual ac ground of each other, the differential isolation can be infinite theoretically without using decoupling structures and dual-polarization are obtained. Since all of the structures are printed on the same layer of the substrate, it can be fabricated easily and is very suitable to be integrated with RF front-end circuits. The measured dual bands are 3.2-3.87 GHz and 5.35-5.83 GHz, along with high isolation better than 35 dB. Simulated and measured results agree well with each other.