A slotted UWB monopole antenna with single port and double ports for dual polarization

The design and performance analysis of a coplanar waveguide fed printed monopole antenna for dual polarization is presented. The rectangular patch monopole has an hour glass shaped slot engraved on it whereas the two ground planes of the CPW are loaded with spiral shaped slots. The feed is made asymmetric with respect to the patch for enhancing the horizontal gain component. The measured (S11 < −10 dB) impedance bandwidth achieved is from 2.8 GHz to 14.0 GHz and corresponds to 133%. The current distribution and radiation patterns at various frequencies are plotted and indicate dual polarization. The antenna is further characterized by a peak gain of 4–5 dBi and will be useful for applications requiring dual polarization capability in the operating band. In addition to the basic design, a two port version of the antenna for diversity applications with impedance bandwidth from 2.7 GHz to 12 GHz and isolation around 15 dB over band is presented at the end. To check the diversity performance of this two port antenna, the envelope correlation coefficient and the diversity gain are calculated and found to be within acceptable limits.