Combined Wideband and Narrowband Antennas for Cognitive Radio Applications

Cognitive or software defined radios have two operating modes, namely the search mode (where the system looks for a band to operate in) and the operating mode (where users transmit and receive data within this band). In the first mode, a very wideband antenna is needed, and in the second a narrower band antenna is required to filter unwanted signals. In this presentation, new antenna concepts are discussed, in which a very wideband and a narrowband antenna are integrated to provide reconfigurable operation within a small volume suitable for hand-held terminals.