The F117 and B2 stealth aircraft provide some of the most widely recognised iconic shapes of the late 20th century. It is less well known, however, that these aircraft have ancestors which date back to the early days of flight prior to the first world war. In the first part of my talk, therefore, I will briefly review some of this early history before concentrating on some aspects of stealth for the 21st century.

The work of the Active Stealth Group at Sheffield is divided into two parts. The first of these is concerned with what might be termed “conventional” or passive, radar absorbing materials. Although examples of these have been under development and in use since the middle 1930’s, there are still areas in which advances can be made. In particular, I will discuss recent work at Sheffield on lightweight very low frequency absorbers which are meant for use in EMC test facilities.

The second part of our work is concerned with active radar absorbing materials and how they might be used as a part of a complete system to enable dynamic control of a scatterer’s radar signature. Collaborative work with colleagues in our Department of Engineering Materials has lead to new active composite materials incorporating doped conducting polymer inclusions. These enable thin layers to be fabricated whose electrical properties can be changed dynamically using a suitable control stimulus. Other work has concentrated on producing layered materials incorporating active meta surfaces which enable dynamic control of radar scattering using a combination of temporal, spectral and spatial techniques. These have resulted in the concept of the phase modulated surface. My talk will review the theory behind this concept and show some examples of its application to the control of scattering from antennas and wind farms.

About our speaker:

Barry Chambers received the Ph.D. degree in electrical engineering in 1968 and the D.Eng. degree (higher doctorate) in 2002, both from the University of Sheffield. In 1968, he joined UBC as a Postdoctoral Teaching Fellow in the Electrical Engineering department, working with Professor Mos Kharadly on surface waveguides. Between 1969 and 1971 he was an assistant professor at UBC. In 1971, he rejoined the University of Sheffield as a Lecturer in the Antennas Group of the Electronic and Electrical Engineering department. He is now Professor of Electromagnetic Engineering at Sheffield and leader of the Active Stealth Group.

His research interests include electromagnetic wave propagation and scattering, automated microwave materials metrology and novel microwave materials and techniques for reducing the radar cross-section of man-made scatterers. His work has influenced the design of a number of current and future military platforms as well as civilian structures such as space-frame radomes, airport buildings and wind farms.

He has acted as a consultant to many companies and organisations including IBM, Shell, UK Ministry of Defence, BAE Systems, UK National Air Traffic Services, Emerson & Cuming and the Royal Swedish and Australian Navies. He is a Chartered Engineer and a Fellow of both the IEEE and the IET (formerly IEE).