Sub-structure characteristic mode computation utilising field-based MM/GTD hybrid methods

Abstract

It is pointed out how the (sub-structure) characteristic modes of a perfect electrically conducting (PEC) object, in the presence of an electrically very large second PEC object, can be computed using a field-based hybrid method that combines the method of moments (MM) and the geometrical theory of diffraction (GTD). An example is provided to demonstrate this. This possibility has not yet been explicitly stated elsewhere (and so perhaps not realised), nor example computations provided. We believe this realisation might widen the scope of application of characteristic mode analysis.

KEYWORDS:

• Characteristic modes
• sub-structure
• field-based hybrid method

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

A. Alakhras

Anas Alahkras received the B.Sc. degree in 2001 from Princess Sumaya University for Technology (Jordan), the M.Sc. degree from the Carleton University (Canada) in 2013, and the Ph.D. degree from the University of Ottawa (Canada) in 2019, all in electrical engineering. He worked as a research assistant in the Microwave Laboratory at Carleton University, and then in the Antenna Group at the University of Ottawa. Prior to his research work in radio-frequency (RF) engineering he had ten years of experience in industry in Canada, and elsewhere, in the software/computer engineering field working on software/database engineering tools, software testing, and FGPAs. His current research interests include electrically small and non-planar antennas, applied electromagnetic field theory, and microwave engineering.

D. A. McNamara

Derek A. McNamara received the B.Sc. degree, with honours, from the University of Cape Town (UCT) in 1976, the M.Sc. degree from the Ohio State University in 1980, and the Ph.D. degree from UCT in 1986, all in electrical engineering. During the periods 1977 to 1979, and 1981 to 1985, he was employed as a Senior Research Engineer at the Council for Scientific & Industrial Research (CSIR), Pretoria, South Africa. He was a professor in the Department of Electrical and Electronic Engineering of the University of Pretoria from 1985 to 1994 (Grinaker Chair in Electromagnetics from 1991–1994), and in 1992 was a Visiting Scientist at the Institut für Höchstfrequenztechnik und Elektronik (IHE) at the University of Karlsruhe, Germany. He was a Principal Member of Technical Staff with the COM DEV Space Group, Ontario, Canada from 1994 through 2000, where he worked on satellite antenna design and development. Since 2000 he has been a professor of electrical engineering in the School of Electrical Engineering & Computer Science (EECS), University of Ottawa, Canada. He is a co-author of the text Introduction to the Uniform Geometrical Theory of Diffraction (Artech House, USA, 1990). He received the John V. Marsh Award for Excellence in Teaching from the University of Ottawa in 2008. He was a Specialist Editor (1990–2000) for Electromagnetics of Computer Physics Communications (published by Elsevier), and an Associate Editor (2010-2014) of the IEEE Transactions on Antennas & Propagation. He is an IEEE Fellow and a Licensed Professional Engineer in the Province of Ontario.