Transformation optics applications in Microwave domain
|讲座名称||Transformation optics applications in Microwave domain|
|讲座人||Prof. Shah Nawaz Burokur|
Shah Nawaz Burokur received the Ph.D. degree from the University of Nantes (France) in 2005. He is actually an Associate Professor at the Université Paris Nanterre. His current research interests are in the areas of microwave and applications of periodic structures, complex media, metamaterials and metasurfaces, in the analysis of integrated planar and conformal circuits and antennas. He is also involved in the design of electromagnetic devices based on the powerful concept of transformation optics. He has published 5 book chapters and more than 60 papers in scientific journals and holds 1 patent on a metamaterial-based antenna. On a national level in France, he is the coordinator of a think tank on new antenna concepts involving metamaterials and metasurfaces.
Transformation Optics (TO) is a powerful tool that enables to control EM fields in unprecedented and unbelievable ways through the use of judiciously engineered materials with parameters that vary spatially [1, 2]. The TO formalism is based on the invariance of Maxwell's equations over space-time coordinate transformations. Such flexibility in controlling EM waves appears to be convenient in the design of innovative devices with performances or special properties difficult to achieve from classical methods and has therefore inspired considerable research interests in wave propagation. The latter concept has led to the design of the now well-known electromagnetic cloak in 2006, and has resulted in the development of conceptual and functional waveguiding and illusion devices. In the field of lenses and antennas, focusing devices, directive antennas, multibeam and isotropic emissions have been proposed.
Here, we propose to design antennas and lenses based on the use of metamaterials materialized from TO concept. Two different formulations are introduced; coordinate transformation and space transformation. While the first one generates anisotropic parameters, the second one allows to have quasi-isotropic material parameters. In this way, broadband performances can be achieved.