Comunications Technology, Research Institute for Information and Communicati
Electrical and Computer Engineering, S. Beheshti University
The design of a novel volcano smoke antenna for UWB indoor applications is presented. The design method is based on a general description for the geometry of UWB monopole antennas which is capable of producing most possible shapes for these antennas. It is also compatible with different optimization methods. In addition to a volcano smoke antenna, this method is used to design two optimized monopole antennas with flat and shaped grounds. The optimization of antennas is carried out by applying a hybrid procedure which begins with a GA global search and completes with a local search. The optimization process aims at minimizing the reflection coefficient of antennas over the operating band while reducing the time-domain distortion of radiated pulses. For Shaped ground and volcano smoke antennas, the reduction of variations in the energy pattern has been added to the optimization goals. The numerical results show the reliability and effectiveness of the whole process. These results also show considerable improvement regarding antenna size and operational characteristics in comparison with similar antennas reported in the literature. The operational characteristics of shaped ground and volcano smoke antennas show that by shaping the ground, better performance could be achieved with smaller radiating elements and ground planes.