ANALYSIS AND DESIGN OF TRANSPARENT CONDUCTIVE COATINGS AND FILTERS

Four types of transparent electrically conductive filters commonly use d for a variety of applications are (1) a free-standing conducting ind uctive mesh, (2) a substrate coated with a conducting inductive mesh, (3) a conducting substrate, and (4) a substrate coated with a continuo us conducting coating. Each can be designed to provide high visible, n ear infrared, and/or far infrared transmittance and high radio frequen cy (rf) and/or microwave attenuation. Theoretical models developed at Itek to predict the optical, rf, and electrical properties of each typ e of filter as a function of conductivity, relaxation time, electronic mobility, thickness, mesh period, and mesh line width are described. The temperature and angle of incidence dependence are also discussed. Simple expressions for predicting the performance of these four types of filters at both optical and rf frequencies provide both insight and useful starting designs.