Wide Band Patch Antenna Structures for Cognitive Radio Applications

The growing demand for the wireless connectivity has insisted a new communication technique to exploit the usage of spectrum in an efficient way. Many Techniques including Cognitive Radio (CR) technology provides the capability to share the spectrum and provides the high band width to the users by using dynamic access techniques. These techniques allow unlicensed secondary users to access the licensed spectrum without any disturbance. A special antenna is required in Cognitive Radio applications for spectrum sensing and communicating. Wide Band antennas are being considered as the most suitable structures for spectrum sensing applications and are perfectly suitable these environments. In this paper, an attempt is made to present the design of simple patch antenna structures by using circular, semi-circular, Semi-circular triangle shaped, semi-circular crown shaped antennas for achieving the wide band characteristics. These structures were analyzed theoretically and the simulation was done by using CST Microwave Studio Suite. All the structures were fabricated and analyzed in between 1-18 GHz frequency range on RT-Duroid substrate. It is found that these Structures achieve an enhanced impedance bandwidth over the frequency ranges other than Ultra Wide Band (UWB) range and up to Ku Band.