Wideband printed slot antenna with polarisation diversity

A single-layer wideband printed slot antenna with polarisation diversity is presented using a hybrid feeding technique. The antenna consists of an aperture-coupled feeding element and a coplanar waveguide feeding element. The aperture-coupled microstrip feed line with a 180° phase difference is used to reduce the cross-polarisation level and improve the isolation level. A circular patch is connected to the coplanar waveguide feed line for good impedance matching. By introducing a fan-shaped slot to separate the ground plane of the radiating elements, the measured isolation between the two feeding ports is better than 30 dB in the whole operating band. The measured -10 dB impedance bandwidths are 49% (4.72-7.75 GHz) and 63% (3.96-7.64 GHz) at port 1 and port 2, respectively. Moreover, the proposed antenna has a compact structure and stable gain over the operating band; thus it can be used in the 5.2/5.8 GHz WLAN and 5.5 GHz WiMAX systems.