A Five-Port Integrated UWB and Narrowband Antennas System Design for CR Applications

The main motive of this paper is to discuss a design of compact five-port integrated ultrawideband (UWB) and narrowband (NB) antennas system for cognitive radio applications. The proposed system composes of one UWB antenna for spectrum sensing and four NB antennas for communication. The UWB and NB antennas are printed on a very compact FR4 substrate of dimensions 40 mm × 36 mm × 1.6 mm. The UWB antenna coupled with port 1 is designed to sense the complete UWB spectrum of 3.1-10.6 GHz approved by Federal Communications Commission in 2002. The four NB antennas operate at different single or dual bands to cover the complete UWB spectrum. In particular, the first NB antenna allied with port 2 achieves a single operating band ranges from 8.7 to 9.92 GHz. The second NB antenna associated with port 3 also covers a single band from 9.82 to 10.74 GHz. The third NB antenna linked to port 4 yields dual bands from 3.06 to 4.23 GHz and 6.33 to 8.83 GHz. The fourth NB antenna accessed at port 5 operates in a single band from 4 to 6.37 GHz. Isolation between the antennas is less than 16 dB over the antennas operating bands. Finally, the proposed integrated structure is fabricated and verified. Experimental results have a good agreement with the simulated results.