Radlab Seminar

Analysis and Design of Curved Metasurface Structures

Zvonimir Sipus

University of Zagreb, Croatia
Thursday, September 20, 2018
4:00pm - 5:00pm
1012 EECS

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About the Event

Metasurfaces that can manipulate electromagnetic waves have garnered significant attention in recent years. To date, the focus has been on planar devices, while many applications require curved surfaces. The objective of this talk is to present a systematic approach to designing curved, multilayer metasurfaces consisting of multiple, patterned sheets. The proposed approach combines the concept of sheet impedance with a new transmission matrix formulation that is applicable to stratified, canonical curved geometries. The results are verified through numerical and experimental metasurface examples that are cylindrical and spherical in shape, as well as body of revolution structures. In the presentation, a method for determining the sheet impedances of curved metasurfaces will be considered for different spectral-domain components of an incoming wave. The analysis approach will also be extended to curved metasurfaces that are inhomogeneous: metasurfaces with a spatially-varying distribution of sheet impedance. The extended formulation also covers metasurfaces that cover only part of a canonical curved surface. Finally, the problem of fabricating curved metasurfaces structures will be discussed. The last part of the presentation will cover periodic structures with higher symmetries. Artificial materials and surfaces are widely used in leaky-wave and holographic surfaces, band-gap materials, and graded-index flat lenses. However, practical realizations are usually limited in terms of bandwidth, loss, fabrication precision, and input-matching. A straightforward approach to overcoming these limitations is to employ higher symmetries in each cell of the periodic medium. The talk will describe quasi-analytical methods to characterize such periodic structures.


Zvonimir Sipus was born in Zagreb, Croatia, in 1964. He received the B.Sc. and M.Sc. degrees in electrical engineering from the University of Zagreb, Croatia, in 1988 and 1991, respectively, and the Ph.D. degree in electrical engineering from the Chalmers University of Technology, Gothenburg, Sweden, in 1997. From 1988 to 1994, he was with the Rudjer Boskovic Institute, Zagreb, Croatia, as a Research Assistant, where he was involved in the development of detectors for explosive gases. In 1994, he joined the Antenna Group, Chalmers University of Technology, where he was involved in research projects concerning conformal antennas and soft and hard surfaces. In 1997, he joined the Faculty of Electrical Engineering and Computing, University of Zagreb, where he is currently a Professor. From 2008 to 2012 and since 2014, he has been the Head of the Department of Wireless Communications. From 1999 to 2005, he was also an Adjunct Researcher with the Department of Electromagnetics, Chalmers University of Technology. Since 2006, he has been involved in teaching with the European School of Antennas. His current research interests include analysis and design of electromagnetic structures with application to antennas, microwaves, and optical communication and sensor systems.

Additional Information

Contact: Alesha Thomas

Phone: 734-764-0500


Sponsor(s): RadLab

Faculty Sponsor: Anthony Grbic

Open to: UM Only