Compact uni-planar antenna with polarization diversity for UWB applicaton in portable devices

A uni-planar multiple-input multiple-output (MIMO) antenna with a small foot print of 23 × 41 mm² for ultra wideband applications is presented. It consists of a coplanar waveguide (CPW) fed circular disk monopole as an antenna element. The isolation between the monopoles are maintained using a 7-shaped stub extended from one of the finite ground of CPW. The compact antenna provides 2:1 VSWR bandwidth of 2.6GHz to more than 11GHz. It also exhibits a high inter-port isolation of > 25dB from 2.6GHz to 11GHz. In addition the antenna provides, good radiation characteristics and a moderate gain across the band, which makes it an excellent candidate for portable UWB applications.