In recent years, transmitarray antennas have attracted growing interest with many antenna researchers. Transmitarrays combines both optical and antenna array theory, leading to a low profile design with high gain, high radiation efficiency, and versatile radiation performance for many wireless communication systems. In this book, comprehensive analysis, new methodologies, and novel designs of transmitarray antennas are presented.

• Detailed analysis for the design of planar space-fed array antennas is presented. The basics of aperture field distribution and the analysis of the array elements are described. The radiation performances (directivity and gain) are discussed using array theory approach, and the impacts of element phase errors are demonstrated.
• The performance of transmitarray design using multilayer frequency selective surfaces (M-FSS) approach is carefully studied, and the transmission phase limit which are generally independent from the selection ofa specific element shape is revealed. The maximum transmission phase range is determined based on the number of layers, substrate permittivity, and the separations between layers.
• In order to reduce the transmitarray design complexity and cost, three different methods have been investigated. As a result, one design is performed using quad-layer cross-slot elements with no dielectric material and another using triple-layer spiral dipole elements. Both designs were fabricated and tested at X-Band for deep space communications. Furthermore, the radiation pattern characteristics were studied under different feed polarization conditions and oblique angles of incident field from the feed.
• New design methodologies are proposed to improve the bandwidth of transmitarray antennas through the control of the transmission phase range of the elements. These design techniques are validated through the fabrication and testing of two quad-layer transmitarray antennas at Ku-band.
• A single-feed quad-beam transmitarray antenna with 50 degrees elevation separation between the beams is investigated, designed, fabricated, and tested at Ku-band. In summary, various challenges in the analysis and design of transmitarray antennas are addressed in this book. New methodologies to improve the bandwidth of transmitarray antennas have been demonstrated. Several prototypes have been fabricated and tested, demonstrating the desirable features and potential new applications of transmitarray antennas.

Autorentext
Ahmed H. Abdelrahman received B.S. and M.S. degrees from The Department of Electrical Engineering, Electronics and Communications, Ain Shams University, Cairo, Egypt, in 2001 and 2010, respectively, and he received a Ph.D. degree in engineering sciences from The Department of Electrical Engineering, University of Mississippi, University, MS, USA, in 2014. Dr. Abdelrahman is currently a research associate with the Antenna Research Group (ARG), in The Department of Electrical, Computer, and Energy Engineering, at The University of Colorado Boulder, Boulder, CO, USA. He also worked as a postdoctoral research associate for almost two years in The Department of Electrical and Computer Engineering at The University of Arizona, Tucson, AZ, USA. Additionally, he possesses over eight years of experience in Satellite Communications industry. He worked as a RF design engineer and a Communication System Engineer in building the low earth orbit satellite Egyptsat-1. His research interests include transmitarray/reflectarray antennas, mobile antennas, reconfigurable antennas, simultaneous transmit and receive (STAR) antennas, satellite communications, and thermoacoustic and millimeter-wave imaging. Dr. Abdelrahman was the recipient of the several prestigious awards, including the Third-Place Winner Student Paper Competition Award at the 2013 ACES Annual Conference, and the Honorable Mention Student Paper Competition at the 2014 IEEE AP-S International Symposium on Antennas and Propagation.Fan Yang received B.S. and M.S. degrees from Tsinghua University, Beijing, China, in 1997 and 1999, respectively, and a Ph.D. degree from the University of California at Los Angeles (UCLA) in 2002. From 19941999, he was a research assistant with the State Key Laboratory of Microwave and Digital Communications, Tsinghua University. From 1999-2002, he was a graduate student researcher with the Antenna Laboratory, UCLA. From 2002-2004, he was a post-doctoral research engineer and instructor with the Electrical Engineering Department, UCLA. In 2004, he joined the Electrical Engineering Department at The University of Mississippi as an assistant professor, and was promoted to a tenured associate professor. In 2011, he joined the Electronic Engineering Department at Tsinghua University as a professor, and has served as the Director of the Microwave and Antenna Institute since then. Prof. Yang's research interests include antennas, surface electromagnetics, computational electromagnetics, and applied electromagnetic systems. He has published over 200 journal articles and conference papers, six book chapters, and three books entitled Scattering Analysis of Periodic Structures Using Finite-Difference Time-Domain Method (Morgan & Claypool, 2012), Electromagnetic Band Gap Structures in Antenna Engineering (Cambridge Univ. Press, 2009), and Electromagnetics and Antenna Optimization Using Taguchi's Method (Morgan & Claypool, 2007). Prof. Yang served as an associate editor of the IEEE Transactions on Antennas and Propagation (20102013) and an associate editor-in-chief of Applied Computational Electromagnetics Society (ACES) Journal (20082014). He was the Technical Program Committee (TPC) Chair of 2014 IEEE International Symposium on Antennas and Propagation and USNC-URSI Radio Science Meeting. Dr. Yang has been the recipient of several prestigious awards and recognitions, including the Young Scientist Award of the 2005 URSI General Assembly and of the 2007 International Symposium on Electromagnetic Theory, the 2008 Junior Faculty Research Award of the University of Mississippi, the 2009 inaugural IEEE Donald G. Dudley Jr. Undergraduate Teaching Award, and the 2011 Recipient of Global Experts Program of China.Atef Z. Elsherbeni received an honor B.Sc. degree in electronics and communications, an honor B.Sc. degree in applied physics, and a M. Eng. degree in electrical engineering, all from Cairo University, Cairo, Egypt, in 1976, 1979, and 1982, respectively, and a Ph.D. degree in electrical engineering from Manitoba University, Winnipeg, Manitoba, Canada, in 1987. He started his engineering career as a part time Software and System Design Engineer from March 1980 to December 1982 at the Automated Data System Center, Cairo, Egypt. From January to August 1987, he was a post doctoral fellow at Manitoba University. Dr. Elsherbeni joined the faculty at the University of Mississippi in August 1987 as an assistant professor of electrical engineering. He advanced to the rank of associate professor in July 1991, and to the rank of professor in July 1997. He was appointed as Associate Dean of Engineering for Research and Graduate Programs from July 2009 to July 2013 at the University of Mississippi. Dr. Elsherbeni joined the Electrical Engineering and Computer Science Department at Colorado School of Mines in August 2013 as the Dobelman Distinguished Chair Professor. He currently is the Electrical Engineering Division Director. He spent a sabbatical term in 1996 at the Electrical Engineering Department, University of California at Los Angeles (UCLA) and was a visiting Professor at Magdeburg University during the summer of 2005 and at Tampere University of Technology in Finland during the summer of 2007. In 2009, he was selected as Finland Distinguished Professor by the Academy of Finland and TEKES. Over the years, Dr. Elsherbeni participated in acquiring millions of dollars to support his research group activities dealing with sca…