This lecture explores the emerging area of reconfigurable antennas from basic concepts that provide insight into fundamental design approaches to advanced techniques and examples that offer important new capabilities for next-generation applications. Antennas are necessary and critical components of communication and radar systems, but sometimes their inability to adjust to new operating scenarios can limit system performance. Making antennas reconfigurable so that their behavior can adapt with changing system requirements or environmental conditions can ameliorate or eliminate these restrictions and provide additional levels of functionality for any system. For example, reconfigurable antennas on portable wireless devices can help to improve a noisy connection or redirect transmitted power to conserve battery life. In large phased arrays, reconfigurable antennas could be used to provide additional capabilities that may result in wider instantaneous frequency bandwidths, more extensive scan volumes, and radiation patterns with more desirable side lobe distributions. Written for individuals with a range of experience, from those with only limited prior knowledge of antennas to those working in the field today, this lecture provides both theoretical foundations and practical considerations for those who want to learn more about this exciting subject. Contents: Introduction / Definitions of Critical Parameters for Antenna Operation / Linkage Between Frequency Response and Radiation Characteristics: Implications for Reconfigurable Antennas / Methods for Achieving Frequency Response Reconfigurability / Methods for Achieving Polarization Reconfigurability / Methods for Achieving Radiation Pattern Reconfigurability / Methods for Achieving Compound Reconfigurable Antennas / Practical Issues for Implementing Reconfigurable Antennas / Conclusions and Directions for Future work

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Jennifer T. Bernhard was born on May 1, 1966, in New Hartford, NY. She received her bachelor of science degree in electrical engineering from Cornell University in 1988. She received her master of science and doctor of philosophy degrees in electrical engineering from Duke University in 1990 and 1994, respectively, with support from a National Science Foundation Graduate Fellowship. During the 1994-1995 academic year, she held the position of postdoctoral research associate with the Departments of Radiation Oncology and Electrical Engineering at Duke University, where she developed circuitry for simultaneous hyperthermia and magnetic resonance imaging thermometry. At Duke, she was also an organizing member of the Women in Science and Engineering (WISE) Project, a graduate student-run organization designed to improve the climate for graduate women in engineering and the sciences. From 1995 to 1999, Prof. Bernhard was an assistant professor in the Department of Electrical and Computer Engineering at the University of New Hampshire, where she held the Class of 1944 Professorship. From 1999 to 2003, she was an assistant professor in the Department of Electrical and Computer Engineering at University of Illinois at Urbana-Champaign. Since 2003, she has held the position of associate professor at Illinois. In 1999 and 2000, she was a NASA-ASEE Summer Faculty Fellow at NASA Glenn Research Center in Cleveland, OH. Prof. Bernhard received the NSF CAREER Award in 2000. She and her students received the 2004 H. A. Wheeler Applications Prize Paper Award from the IEEE Antenna and Propagation Society for their article published in the March 2003 issue of the IEEE Transactions on Antennas and Propagation. Prof. Bernhard's research interests include reconfigurable and wideband microwave antennas and circuits, wireless sensors and sensor networks, high-speed wireless data communication, electromagnetic compatibility, and electromagnetics for industrial, agricultural, and medicalapplications. She served as an associate editor for IEEE Transactions on Antennas and Propagation from 2001 to 2007 and as an associate editor for IEEE Antennas and Wireless Propagation Letters from 2001 to 2005. She is also a member of the editorial board of Smart Structures and Systems. She is a member of URSI Commissions B and D, Tau Beta Pi, Eta Kappa Nu, Sigma Xi, and ASEE. She is a senior member of the IEEE and served as an elected member of the IEEE Antennas and Propagation Society's Administrative Committee from 2004 to 2006. She is 2007 president-elect of the IEEE Antennas and Propagation Society.