MIMO antenna design for WALN applications

A closely-packed coplanar waveguide (CPW)-fed dual band multi-input-multi-output (MIMO) antenna operating at WLAN (IEEE 802.11a/b/g) is presented. A metal strip is located between signal and ground of the CPW to excite the surface wave mode that contributes to not only two resonant modes at lower (2.4-2.48 GHz) and higher (5.13-5.825 GHz) bands, but also a good isolation (S₂₁<;-15 dB) over these bands. In this case, the spacing between two antennas can be reduced to 2 mm (0.016λ at 2.45 GHz) without any decoupling elements or network. The experimental results show good agreement with the simulation results, demonstrating the feasibility of the proposed method.