Robert H. Caverly was born in Cincinnati, Ohio in 1954. He received his Ph.D. degree in electrical engineering from The Johns Hopkins University, Baltimore, MD, in 1983. He received the M.S.E.E and B.S.E.E degrees from the North Carolina State University, Raleigh, in 1978 and 1976, respectively. Dr. Caverly has been a faculty member at Villanova University in the Department of Electrical and Computer Engineering since 1997 and is a Full Professor. Previously, he was employed for more than 14 years at the University of Massachusetts Dartmouth (formerly Southeastern Massachusetts University). In 1990, he was a Visiting Research Fellow with the Microwave Solid-State Group at the University of Leeds in the United Kingdom. Dr. Caverly’s research interests are focused on the characterization of semiconductor devices such as PIN diodes and FETs in the microwave and RF control environment, with application areas in communication systems, radar and magnetic resonance imaging. Besides microwave semiconductor electronics, his other interests include analog and digital CMOS VLSI design, an area where he has taught a number of workshops both in this country and outside, as well as graduate and undergraduate courses at the university. He has published more than 100 journal and conference papers in these and other technical and educational areas. He has also published two books, ‘CMOS RFIC Design Principles’ (2007) and ‘Microwave and RF Semiconductor Control Device Modeling’ (2016), both published by Artech House. He is the current Editor-in-Chief of the IEEE Microwave Magazine (through 2020), and is a member of the editorial board of the IEEE Transactions of Microwave Theory and Techniques. For the MTT Society, he is current a member of MTT-10 and MTT-17, and was past chairperson of MTT-17. In addition to being a Fellow of the IEEE, he was Distinguished Microwave Lecturer for the IEEE Microwave Theory and Techniques Society (2014-2016, Emeritus currently). He is a 1987 recipient of the Dow Outstanding Young Faculty Award from The American Society of Engineering Education and the 2007 and 2013 recipient of the Fr. Farrell Award from the College of Engineering at Villanova University. Dr. Caverly is also a Program Evaluator for ABET, representing the IEEE. During his career, he has also been a consultant for a number of microwave industries working on various microwave control element projects.
A variety of semiconductor technologies is now available for RF and microwave control. This talk will address such control technologies as PIN diodes and FET-based elements and issues related to the choice of control technology for particular applications. Control design considerations will also be discussed.
Magnetic Resonance Imaging (MRI) scanners are an important diagnostic tool for the medical practitioner. MRI provides a non-invasive means of imaging soft tissues and to obtain real-time images of the cardiovascular system and other dynamic changes in the human body. MRI scanners rely heavily on a number of topical areas of interest to Electrical Engineers: image processing, high speed computing and RF (radio frequency) systems and components. This presentation will focus on some of the RF aspects of the MR process and MR scanners. A primer on the physical phenomenon behind magnetic resonance will start the presentation and include a discussion of the origin of the MR signal. The need for the high static magnetic field (B0), the use of gradient coils for MR signal location, simple RF pulse sequences and how they are used in image construction will be covered. This MR image construction process and the control of the various steps that manipulate the atomic nuclei to generate the final MR diagnostic image put demanding constraints on RF equipment capabilities and these will be discussed, along with a high-level overview of the various components making up conventional MRI systems. This high-level overview will include a look at various examples of transmit and receive RF systems and examples of transmit and receive coils that make up MR scanners and system diagrams for both the RF transmit and receive paths. The talk with then narrow in scope to look at how these RF coils are modeled and controlled in both transmit and receive states and how these components are used for transmit/receive switching and patient and equipment protection.