Recent Featured Articles
A Theory of Antenna Electromagnetic Near Field — Parts I and II
Said M. Mikki and Yahia M. Antar
Abstract: We present in this work a comprehensive theory of antenna near fields in two parts, highlighting in particular the engineering perspective.
Part I starts by providing a general conceptual framework for the more detailed spectral theory to be developed in Part II. The present paper proceeds by proposing a general spatial description for the electromagnetic field in the antenna exterior region based on an asymptotic interpretation of the Wilcox expansion. ...Full Feature Article
What is ‘Student-Centered’ Electromagnetic Instruction?
Krishnasamy T. Selvan
This article discusses the meaning of the term ‘student-centered teaching’ with reference to literature. A review of activities suggested in the literature for aiding electromagnetic education is also undertaken in this background...Full Feature Article
WHO WAS JAMES CLERK MAXWELL AND WHAT WAS/IS HIS ELECTROMAGNETIC THEORY
Tapan K. Sarkar*, Magdalena Salazar-Palma**, Dipak L. Sengupta
ABSTRACT - The Electromagnetic community make profuse utilization of Maxwell’s equations, his theory and their applications. It is arguable that very few of us have clear ideas about what exactly Maxwell did and what kind of scientist he was. In fact, he developed many of the fundamental ideas in electrical engineering and provided mathematical language for their exposition. His contributions to other branches of science are no less significant. He was not only one of the great scientists of the nineteenth century but also is great for all time. To this end, the present essay starts with a brief outline of his life; and then it provides a short but critical discussion of his original contributions in electromagnetics and their evolution as his electromagnetic theory. We also give a cursory review of his significant contributions in other areas of science. It is hoped that this will provide the electromagnetic community readers with better and more complete appreciation of James Clerk Maxwell as a scientist as well as of his electromagnetic theory as we know now it.... Full Feature Article
Antennas, How Many Do We Need?
Peter C.T. Song BEng(Hons) PhD CEng MIET SMIEE
David Barker BEng(Hons) MSc CEng MIET MIEEE
One of the key components interfacing between the radio hardware and the ‘Ether’, i.e. the air-interface for wireless communication is the antenna. With tremendous growth and demand for high speed high data rate wireless communication, more and more antennas, and antennas covering a multitude of frequency bands are required. This paper begins by giving an innovations overview of the evolution of the wireless standards and access technologies, driving antenna innovations from a conventional single narrow band component to today’s advances capable of multiple services, and cognitive capable antenna systems. The paper will focus on antenna developments in mobile communication systems, in particular cellular base station and cellular handset antennas. Key technological advancements will be presented. In conclusion, we will respond to the question of how many antennas do we really need...Full Feature Article
Solving the Generalized Poisson Equation Using the Finite-Difference Method (FDM)
James R. Nagel
The University of Utah
The Poisson equation is a very powerful tool for modeling the behavior of electrostatic systems, but unfortunately may only be solved analytically for very simplified models. Consequently, numerical simulation must be utilized in order to model the behavior of complex geometries with practical value. Although there are several competing algorithms for achieving this goal, one of the simplest and more straightforward of these is called the finite-difference method (FDM). At its core, FDM is nothing more than a direct conversion of the Poisson equation from continuous functions and operators into their discretely-sampled counterparts...Full Feature Article
Cognitive Radio: The New Frontier for Antenna Design?
Professor Christos G. Christodoulou
The University of New Mexico
Today, research in cognitive radio is aimed at developing efficient wireless communication strategies to make use of this unused spectrum. The idea is to make smart wireless devices that can observe their RF environment and detect unused frequency bands in real time. That way, we can operate more of wireless devices in the same frequency bands that are already in use. It is desirable to develop devices that can learn from their observations and make their own decisions about when and how to transmit without disrupting any existing wireless connections. Full feature article
How should we excite non-engineers about our professions as antenna engineers and researchers?
Professor Yahya Rahmat-Samii
In today’s society, we tend to size people up almost immediately. Among the most quintessential questions we ask in order to formulate our opinion is simply, “what do you do?” In our profession, this is a rather tough question to answer and several years ago, when I was the Department Chair at the Electrical Engineering Department at UCLA, I had to do just that. I was invited to give a luncheon talk at the Beverly Hills Rotary Club at the famous Beverly Hills Hotel. The luncheon guests were some of the top business professionals such as bank executives, hotel managers, doctors, lawyers, etc. After a delicious lunch in a beautiful setting, it was then my turn to talk for about forty five minutes about what I do as an electromagnetic/antenna scientist and engineer. You can probably imagine how unusual it is to excite this kind of audience about the nature of the work we do! Full feature article