Radio Frequency Transparent Thermal Protection System Materials

The exterior surfaces of high speed missiles and other air structures experience high temperatures. These structures often include antennas that must transmit and receive through these surfaces, thereby requiring the skins to be transparent to RF energy. Sometimes it is beneficial for the surfaces to include the ability to reflect, or appear to be conductive to, radio frequencies outside the band of the antenna. This can be accomplished through frequency selective surfaces. This project will design and develop a novel integrated structure using production proven materials that: can withstand high temperatures, insulate antennas and associated electronics from the heat, is transparent to specific radio frequencies, and reflects RF energy outside the antenna band by combining multiple materials and technologies developed under previous SBIR programs. Our design leverages the dielectric properties of the low density thermal insulation to enhance RF transmission characteristics. The design also addresses the attachment of these integrated structures to the vehicle by leveraging the capability of our proposed ceramic material to include drilled holes for high temperature fasteners that achieve load transfer, minimize heat transfer, and accommodate differential coefficients of thermal expansion. Approved for Public Release | 19-MDA-9932 (21 Feb 19)