Ebrahimi, Elham; Hall, Peter S. (Electronic, Electrical and Computer Engineering, University of Birmingham, Birmingham, B15 2TT, United Kingdom)
An antenna for cognitive radio application is presented in this paper. The structure is a novel combination of wideband and narrowband antennas into the same volume. The wideband antenna is a CPW fed printed hour-glass shaped monopole which operates from 3 to 11GHz. The narrowband antenna is a microstrip patch printed on the reverse side of the substrate, and connected to the wideband antenna via a shorting pin and designed to operate from 5.15 to 5.35GHz. This design can be suitable for cognitive radio applications where a wideband antenna is required for spectrum sensing and a narrowband antenna for operation which can be tuned over a wide bandwidth using an external tuning circuit. The UWB and WLAN bands were chosen to demonstrate the integration principle, although cognitive radio may initially cover lower frequencies than these.