Compact dual band-notched UWB multiple-input multiple-output antenna for portable applications

A compact ultra-wideband (UWB) multiple-input multiple-output (MIMO) antenna with dual band-notched characteristics for portable applications is proposed in this article. The antenna is fed by coplanar waveguide and has four feeding ports with the size of 50 x 50 mm(2). By etching split-ring resonator slots on the radiation patches, dual notches filtering out the 3.5 GHz WiMAX and 5.5 GHz WLAN bands can be achieved. The design process is given step-by-step and the band-notched mechanism is studied with the surface current distributions. Moreover, the band-notched characteristics of cylindrical conformal antenna is analyzed in this article. The experimental results show that the proposed antenna can be widely used in UWB communication system with good radiation characteristics, stable gain, and low envelope correlation coefficient. The idea embodied in this article can also be used to guide for the research of band-notched conformal UWB MIMO antenna.