Dispersion of dielectric composites: quasi-dynamic characterizations and applications

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Jiaran Qi Name of the doctoral dissertation Dispersion of dielectric composites: quasi-dynamic characterizations and applications Publisher School of Electrical Engineering Unit Department of Radio Science and Engineering Series Aalto University publication series DOCTORAL DISSERTATIONS 61/2011 Field of research Electromagnetics Manuscript submitted 7 April 2011 Manuscript revised 13 June 2011 Date of the defence 14 September 2011 Language English Monograph Article dissertation (summary + original articles) Abstract Characterization of the dispersion of macroscopic electromagnetic properties of composite materials is a challenging task, but it offers an efficient and effective path to interpret features or phenomena, and to design artificial structures with desired properties. In this thesis, the quasi-dynamic homogenization is performed to characterize the dispersive electric properties of a class of dielectric composites. Although their geometry configurations are very simple, many fundamental yet significant features as well as problems appear during the quasidynamic homogenization process, and are thus studied in detail. The quasi-dynamic region is defined to include the quasi-static one and the frequency range close to the quasi-static limit. This thesis focuses on various homogenization models and techniques. In addition, the homogenization results by the proposed techniques are applied to explore several significant homogenization-related problems, such as quantification of the quasi-static limit, evaluation of a homogenization model, as well as the temporal pulse dynamics in dielectric (composite) materials.Characterization of the dispersion of macroscopic electromagnetic properties of composite materials is a challenging task, but it offers an efficient and effective path to interpret features or phenomena, and to design artificial structures with desired properties. In this thesis, the quasi-dynamic homogenization is performed to characterize the dispersive electric properties of a class of dielectric composites. Although their geometry configurations are very simple, many fundamental yet significant features as well as problems appear during the quasidynamic homogenization process, and are thus studied in detail. The quasi-dynamic region is defined to include the quasi-static one and the frequency range close to the quasi-static limit. This thesis focuses on various homogenization models and techniques. In addition, the homogenization results by the proposed techniques are applied to explore several significant homogenization-related problems, such as quantification of the quasi-static limit, evaluation of a homogenization model, as well as the temporal pulse dynamics in dielectric (composite) materials.