Artificial Dielectrics for High Power Microwave Applications

"The objective of this proposal is to demonstrate the feasibility of producing lightweight artificial dielectric materials for High Power Microwave (HPM) source lens designs. Conventional HPM lenses are usually machined from a dense material exhibiting thedesired electrical characteristics, such as polyethylene, and are inherently heavy. Heavy lenses are undesirable for handheld, mobile, aircraft, and especially spacecraft applications.There is an alternative approach to source lens design. Lightweight artificial dielectrics can be constructed of a composite material. One element of the composite is a low loss background (or substrate) dielectric and the other is an additive consistingof metallic particles, metallic flakes, or conducting spheres. The additive acts to increase the dielectric constant of the substrate material and a wide range of values are theoretically possible. Additionally, if the substrate is made of plastic,manufacturing of components can be greatly simplified by using injection molding techniques and the weight can be significantly reduced by introducing voids into the material. Other more complicated alternatives exist for manufacturing compositedielectrics for use in narrow band applications. In this case, resonant structures are used in a periodic array and theoretically any value of permittivity and permeability, even negative, can be achieved. Any application suffering a penalty for theweight of conv