Ultra High Performance Radar Absorbing Material

ABSTRACT: Traditional anechoic chamber wall treatments have consisted of geometrically tapered carbon loaded foam, which provides good near-normal incidence absorption of specular energy. While this material has served the testing community well over the last few decades, it is fundamentally limited because of the high level of diffuse scatter (tip diffraction), that increases the overall noise level in a chamber. To reach the reduced noise levels necessary for modern aircraft avionics and antenna testing, a new paradigm in anechoic chamber absorber is needed. The research program outlined in this proposal addresses this need by applying recently developed computational tools and design methodologies for electromagnetic materials. Through full-wave computational design, the material performance will be optimized over the full range of angles and frequencies needed in this application. Unlike traditional pyramidal absorber, the proposed absorber concept has an inherently low amount of diffuse scatter while improving specular performance over the traditional materials. The proposed concept also leverages current materials technologies and manufacturing methods so that anticipated manufacturing costs should be in line with current pyramidal absorber materials. BENEFIT: While the BAF is the primary near-term customer for the proposed HEPA-RAM, there are numerous anechoic chambers at DoD facilities across the United States. Because the performance specifications are significantly beyond the existing state-of-the-art in pyramidal absorber, The HEPA-RAM promises to be a game-changer in terms of increased measurement capability at these ranges. Furthermore, the ubiquitousness of wireless consumer electronics has lead to a large demand for RF testing by commercial companies as well. Large corporations such as Motorola and Apple, operate numerous anechoic chambers for testing commercial products, and the HEPA-RAM concept is directly applicable for increasing their measurement capabilities as well.