Design of Reconfigurable Antennas Using Graph Models

Joseph Costantine received his Ph.D. degree from the University of New Mexico in 2009 where he also completed a post-doc fellowship in July 2010. Dr. Costantine has a Masters in Computer and Communications Engineering from the American University of Beirut in 2006. His bachelor's degree is in Electrical, Electronics, Computer, and Communications Engineering from the second branch of the Faculty of Engineering in the Lebanese University in 2004. He is the recipient of many awards including the summer faculty fellowship from the space vehicles directorate in Albuquerque, NM, for three consecutive years. He has published many research papers and has several patents. His major research interests reside in reconfigurable antennas for wireless communication systems, cognitive radio, antennas for biomedical applications, and deployable antennas for small satellitesYoussef Tawk received the Ph.D. degree from the University of New Mexico in 2011 where he also completed a post-doc fellowship in August 2012. Dr. Tawk has a Master's degree in Electrical and Computer Engineering from the American University of Beirut in 2008. His bachelor's degree in Computer and Communication Engineering was received with highest distinction in 2006 from Notre Dame University, Louaize, Lebanon. He received many awards and honors throughout his studies. He has published several journal and conference papers and has several issued patents. His research interests include reconfigurable antenna systems, cognitive radio, radio-frequency (RF) electronic design, photonics, and millimeter-wave technologyChristos G. Christodoulou received his Ph.D. degree in Electrical Engineering from North Carolina State University in 1985. He served as a faculty member in the University of Central Florida, Orlando, from 1985 to 1998. In 1999, he joined the faculty of the Electrical and Computer Engineering Department of the University of New Mexico, where he served as the Chair of the Department from 1999 to2005. He is a Fellow member of IEEE and a member of Commission B of URSI. Currently he is the director for COSMIAC (Configurable Space Microsystems Innovations & Applications Center at UNM). He is the recipient of the 2010 IEEE John Krauss Antenna Award, the Lawton-Ellis Award, and the Gardner Zemke Professorship at the University of New Mexico. He has published about 400 papers in journals and conferences, has 13 book chapters, and has co- 136 AUTHORS' BIOGRAPHIES authored five books. His research interests are in the areas of modeling of electromagnetic systems, adaptive array antennas, high power microwave antennas, reconfigurable antenna systems, cognitive radio, and smart RF/photonics.

This lecture discusses the use of graph models to represent reconfigurable antennas. The rise of antennas that adapt to their environment and change their operation based on the user's request hasn't been met with clear design guidelines. There is a need to propose some rules for the optimization of any reconfigurable antenna design and performance. Since reconfigurable antennas are seen as a collection of self-organizing parts, graph models can be introduced to relate each possible topology to a corresponding electromagnetic performance in terms of achieving a characteristic frequency of operation, impedance, and polarization. These models help designers understand reconfigurable antenna structures and enhance their functionality since they transform antennas from bulky devices into mathematical and software accessible models. The use of graphs facilitates the software control and cognition ability of reconfigurable antennas while optimizing their performance.This lecture also discusses the reduction of redundancy, complexity and reliability of reconfigurable antennas and reconfigurable antenna arrays. The full analysis of these parameters allows a better reconfigurable antenna implementation in wireless and space communications platforms. The use of graph models to reduce the complexity while preserving the reliability of reconfigurable antennas allow a better incorporation in applications such as cognitive radio, MIMO, satellite communications, and personal communication systems. A swifter response time is achieved with less cost and losses. This lecture is written for individuals who wish to venture into the field of reconfigurable antennas, with a little prior experience in this area, and learn how graph rules and theory, mainly used in the field of computer science, networking, and control systems can be applied to electromagnetic structures. This lecture will walk the reader through a design and analysis process of reconfigurable antennas using graph models with a practical and theoretical outlook.

Introduction to Reconfigurable Antennas.- Graph Modeling Reconfigurable Antennas.- Reconfigurable Antenna Design Using Graph Models.- Redundancy Reduction in Reconfigurable Antenna Structures.- Analyzing the Complexity and Reliability of Switch-Frequency Reconfigurable Antennas Using Graph Models.- Complexity Versus Reliability in Arrays of Reconfigurable Antennas.- Detection and Correction of Switch Failures in Switch Reconfigurable Antenna Arrays.- Conclusion.- Bibliography.- Authors' Biographies.