Compact Size Wireless Power Transfer Using Defected Ground Structures

This book addresses the design challenges in near-field wireless power transfer (WPT) systems, such as high efficiency, compact size, and long transmission range. It presents new low-profile designs for the TX/RX structures using different shapes of defected ground structures (DGS) like (H, semi-H, and spiral-strips DGS). Most near-field WPT systems depend on magnetic resonant coupling (MRC) using 3-D wire loops or helical antennas, which are often bulky. This, in turn, poses technical difficulties in their application in small electronic devices and biomedical implants. To obtain compact structures, printed spiral coils (PSCs) have recently emerged as a candidate for low-profile WPT systems. However, most of the MRC WPT systems that use PSCs have limitations in the maximum achievable efficiency due to the feeding method. Inductive feeding constrains the geometric dimensions of the main transmitting (TX)/receiving (RX) resonators, which do not achieve the maximum achievable unloaded quality factor. This book will be of interest to researchers and professionals working on WPT-related problems.

Sherif Hekal is currently an Assistant Professor at the Department of Electronics and Communications Engineering, Faculty of Engineering at Shoubra - Benha University, Cairo. He received his B.Sc. and M.Sc. degrees in Electrical Engineering from the same university in 2007 and 2012, respectively. He received his Ph.D. from the Egypt-Japan University of Science and Technology (E-JUST) in Electronics and Communications Engineering in 2016. As part of his PhD program, he spent time at the Faculty of Information Science and Electrical Engineering, Kyushu University, Fukuoka, Japan. Dr. Hekal also worked as a communications engineer at Motorola Co. Ltd. and Nokia Siemens Networks in the field of 2G/3G RF optimization. His research interests include RF/microwave applications, antennas, wireless power transfer, and energy harvesting systems. Dr. Ahmed Allam is currently an Associate Professor at the Department of Electronics and Communications Engineering, Egypt-Japan University of Science and Technology, Alexandria, Egypt. He received his B.Sc. in Electrical Engineering from Alexandria University, Egypt, and his M.Eng. and Ph.D. from the University of Alberta, Canada. From April 1994 to January 1998, he worked as an instrument engineer with Schlumberger. From May 2000 to September 2001, he was with Murandi Communications Ltd., Calgary, Alberta, where he worked on RF transceivers design. From April 2007 to April 2008, he worked on RF CMOS transceivers design at Scanimetrics Inc., Edmonton, Alberta. His research interests include the design of RF circuits and systems. Adel B. Abdel-Rahman is currently a Professor at the Department of Electronics and Communications Engineering, Egypt-Japan University of Science and Technology, Alexandria, Egypt. He received his B.S. and M.S. in Electrical Engineering, Communication, and Electronics from Assiut University, Egypt, and his Dr.-Ing. degree in Communication Engineering from Otto von Guericke University, Germany in 2005. Since October 2006, he has been an Assistant Professor at the Electrical Engineering Department, South Valley University, Qena, Egypt. He has published more than 120 refereed journal and conference papers and has two patents. He was the Executive Director for Information and Communication Technology, South Valley University, from 2010-2012. Since October 2012, he joined the School of Electronics, Communications and Computer Engineering, Egypt-Japan University of Science and Technology (E-JUST), Alexandria, Egypt, and has been the Dean of the Faculty of Computers and Information, South Valley University from 2016-2018. His research interests include the design and analysis of antennas, filters, millimeter-wave devices, WPT, and metamaterials and their application in wireless communication, as well as optimization techniques with applications to microwave devices and antenna arrays. Ramesh K. Pokharel is a Professor in the Department of I&E Visionaries at Kyushu University. He received M.E. and PhD in Electrical Engineering from the University of Tokyo, Japan in 2000 and 2003, respectively. In April 2005, he joined the Graduate School of Information Science and Electrical Engineering, Kyushu University. He was the secretary of IEEE MTT-S Japan Society from Jan 2012 to Dec. 2013 and the deputy-chair of the Education committee of IEEE-MTT-S Japan Society from Jan. 2014 to Dec. 2017 and has been serving as the chair of the same committee since 2017. His current research interests include low cost RFIC and analog circuits for microwave and millimeter wave wireless communications, and on-chip meta-materials in CMOS.

1. Introduction.- 2. Wireless Power Transfer Technology and State-of-the-Art.- 3. Wireless Power Transfer Using DGSs.- 4. Design Methods.- 5. Conclusions and Future Directions.