A technique for fabricating free standing electrically thick metallic mesh and parallel wire grids for use as submillimeter wavelength filters and polarizers

A method for fabricating thick metallic mesh with a grid constant as low as 0.0025 in. and wall-thickness-to-depth aspect ratios greater than 5:1 is described. The method can be used to produce sharp cutoff submillimeter-wave filters and polarizers previously realizable only in thin screen form or on a dielectric backing. The uniformity and flatness of the final grids are competitive with those of any current fabrication method, and the relative simplicity of fabrication makes them cost effective in small quantities. The transmission curve of the free-standing mesh at normal incidence agrees well with the approximate analysis of C.C. Chen (1973). The behavior at other incident angles will be measured for grids having square and rectangular holes. Other applications for the fabrication process include high-aspect-ratio screens containing any electroformable hole pattern or shape and three-dimensional cagelike structures which could be formed from silicon cubes.<>