Design of planar ultra-wideband antenna with polarization diversity and high isolation

This paper has presented a compact planar antenna for ultra-wideband (UWB) multiple-input-multiple-output (MIMO) applications. The polarization diversity is obtained by employing dual planar UWB antenna elements and rotating one 90 degrees with respect to the other one. The microstrip-fed element consists of a rectangular ground plane and a rectangular radiating patch. In addition, an inverted-L shaped strip is connected to the ground plane for reducing the whole size and improving the impedance matching. The results have confirmed that the proposed element occupies a size of 24×16×0.8 mm³ and achieves a wideband bandwidth from 3 to over 10 GHz. Moreover, the operating frequency band of the UWB MIMO antenna with a size of 24×44×0.8 mm³ can cover 3-10 GHz and the port-to-port isolation is around 20 dB.