Progress towards reconfigurable electromagnetic structures

This paper reviews progress in the design, realisation and application of large-area, reconfigurable electromagnetic structures (RES) based on polymer composite materials having dynamically controllable resistance and/or capacitance. So far, much of the work of Chambers et. al. (see Proc. 17th AMTA Symposium, Williamsburg, VA, USA, p.318-22) has been concerned with radar absorbing materials, but some of the polymer systems currently under investigation are intended for use in electromagnetic windows. Historically, windows, reflectors and absorbers have always been considered as quite separate entities. With the advent of "electromagnetically smart" materials and structures, however, this distinction is no longer clear-cut since, in principle, one may be reconfigured to behave as another. This realisation is leading to a fruitful interchange of ideas and techniques between previously disparate but mature areas of expertise. Radome structures, reflector antennas and radar absorbing materials are also examined.