Reconfigurable Antennas and Band Gap Materials

The realisation of cognitive radio systems will involve producing antenna and microwave components that can be reconfigured for different parts of the frequency spectrum. Many antennas and related components operate at multiple frequency bands but further reconfigurabilty and miniaturisation will be necessary to meet cognitive radio specifications. In this presentation, the speakers describe work on retunable antennas and electromagnetic band gap materials that have significant potential to meet the requirements for this application. The band gap material consists of a dual layer of square element based designs with varactor diodes. The tuning ranges for each band were from 700 MHz to 1200 MHz and from 1700 MHz to 2600 MHz. In addition, antennas that can be tuned using liquid dielectrics and MEMs switches are described.