Ultra-wideband planar monopole integrated with cylindrical dielectric resonator antenna

An ultra-wideband (UWB) planar monopole antenna integrated with a narrow-band (NB) cylindrical dielectric resonator antenna (DRA) is presented. The proposed antenna consists of a UWB monopole excited by a coplanar waveguide (CPW) and a DRA excited by a slot which displays a NB characteristic. Mode HEM
_11δ
is excited in the NB antenna. The UWB and NB antenna provide a 2:1 voltage standing wave ratio (VSWR) bandwidth for 3.05 - 13.5 GHz and 5.1 - 5.8 GHz, respectively, with the same polarization and reasonable isolation (better than -10 dB ) between the two ports. This is a promising candidate for applications of cognitive radio, where a UWB antenna is for spectrum sensing and a NB antenna for communication operation.