Metamaterijali - poziv na predavanja

"Advances in Metamaterial Surfaces and Structures"

Prof. Anthony Grbic, University of Michigan

Kratki sadržaj

The talk will begin with a brief introduction to electromagnetic metamaterials. These are artificial, subwavelength-structured materials that exhibit tailored electromagnetic properties. They can be designed to possess a wide range of properties, even those not found in natural materials. For this reason, metamaterials have received widespread attention in recent years and have been the subject of an intense research effort in the engineering and physics communities. This presentation will describe various directions we are pursuing in this emerging field of research. The talk will focus on three research thrusts: the development of non-periodic metamaterial surfaces (near-field plates) for near-field focusing and probing applications, the extension of existing transmission-line based metamaterials to include tensor material properties, as well as the design of high performance volumetric metamaterials with wide bandwidths of operation and reduced losses. Toward the end of the talk, metamaterial-based devices will be shown and application areas identified for the proposed structures.

O autoru

Anthony Grbic received the B.A.Sc., M.A.Sc., and Ph.D. degrees in Electrical Engineering from the University of Toronto, Canada, in 1998, 2000, and 2005, respectively. In January 2006, he joined the Department of Electrical Engineering and Computer Science at the University of Michigan, where he is currently an Assistant Professor. His research interests lie in the broad area of applied electromagnetics and include engineered electromagnetic structures (metamaterials, electromagnetic bandgap materials, frequency selective surfaces), printed antennas, microwave circuits and analytical electromagnetics.  Dr. Grbic received the Best Student Paper Award at the 2000 Antenna Technology and Applied Electromagnetics (ANTEM) Symposium and an IEEE Microwave Theory and Techniques Society Graduate Fellowship in 2001. In 2008, he was the recipient of an AFOSR Young Investigator Award as well as an NSF Faculty Early Career Development Award. In January 2010, Dr. Grbic was awarded a Presidential Early Career Award for Scientists and Engineers (PECASE).

"Metamaterial-inspired, Multi-functional, Electrically Small, Near-field Resonant Parasitic Antennas"

Prof. Richard W. Ziolkowski, University of Arizona

Kratki sadržaj

A number of advances in the use of metamaterials and metamaterial-inspired structures to improve the overall efficiency and bandwidth performance of electrically small antennas (ESAs) in the VHF, UHF and microwave regimes will be reviewed.
Metamaterials have led to a different paradigm for achieving electrically small radiating and scattering systems. Many of our initial electric and magnetic metamaterial-based ESA designs have been realized through the introduction of the corresponding metamaterial-inspired near-field resonant parasitic element antennas. Their further miniaturization at VHF and UHF frequencies has been enabled by introducing lumped elements as was done to achieve the highly subwavelength ENG, MNG, and DNG unit cells. Many of these metamaterial-inspired ESA designs have now been fabricated and tested. The measurement results are in very nice agreement with their predicted behaviors. These results will be presented and discussed. While these initial efforts emphasized high overall efficiencies without using any external matching networks, more recent resonant near-field parasitic designs have also explored how close their Q values can come to the Chu limit. Several of these ESA designs, their frequency bandwidths, and their associated Q values will be compared to various reported limits.
It will also be shown that the corresponding active metamaterial element versions of these metamaterial-inspired ESA designs, i.e., replacing the internal passive elements in successful narrow bandwidth, high overall efficiency designs with active elements, could potentially have very large instantaneous bandwidths while maintaining their overall efficiencies even when they are very electrically small. Further considerations of multi-band systems within the same real estate allowance (electrical size or footprint), along with potential applications, will also be described.

O autoru

 Richard W. Ziolkowski (ScB 1974, Brown University, MS'75 and PhD'80 from the University of Illinois at Urbana-Champaign, all in Physics) is the Litton Industries John M. Leonis Distinguished Professor in the Department of Electrical and Computer Engineering at the University of Arizona. He is also a Professor in the College of Optical Sciences at the University of Arizona. He was the Computational Electronics and Electromagnetics Thrust Area Leader in the Engineering Research Division at the Lawrence Livermore National Laboratory before joining the University of Arizona in 1990. Professor Ziolkowski is a Fellow of both the Institute of Electrical and Electronics Engineers (IEEE) and the Optical Society of America. He was President of the IEEE Antennas and Propagation Society in 2005. He and Prof. Nader Engheta, University of Pennsylvania, are Co-Editors of the best selling 2006 IEEE-Wiley book, Metamaterials: Physics and Engineering Explorations.