The rapid increase in the demand for wideband wireless spectrum has engendered the rapid expansion of the high-speed and multimedia wireless services market. Access to the much-needed usable spectrum is scarce due to current spectrum segmentation and complex operations related to managing the allocated frequencies. Accordingly, developing wireless communication platforms has become significantly challenging. Cognitive radio (CR) is a technology that provide an answer to the scarcity problem due to its dynamic spectrum management stemming from its capability of autonomous reconfiguration by learning and adapting to its surrounding environment; this allows for efficient radio spectrum sharing.
For CR, there is a need for wideband antennas to monitor the channel activity and scan all the frequency bands. In addition, wideband antennas are vital to satisfy the increasing demand for broad bandwidth in wireless communication. The fundamental RF configuration of a CR system is consists of a reconfigurable transmit-receive (TR) antenna and a sensing antenna. The wireless channel for unused frequency bands is monitored by sensing antenna. At the same time, the reconfigurable TR antenna performs the vital transmission. A variety of antennas have been engineered with CR capabilities. With CR, the antenna size is vital, thus requiring miniaturised antennas. Therefore, the predominant focus of this research will be to design, test, and fabricate miniaturized wideband antennas. The antenna must have reconfigurable capabilities such as pattern diversity and beam scanning to perform sensing of a wide range of frequencies to detect unutilised frequency bands and fully exploit the CR systems.
Professor Karu Esselle, The University of Technology Sydney
Cho Hilary Scott Nkimbeng