Ceramic Composite Windows and Radomes for Hypersonic Vehicles Navy SBIR FY2007.1 Sol No.: Navy SBIR FY2007.1 Topic No.: N07-094 Topic Title: Ceramic Composite Windows and Radomes for Hypersonic Vehicles Proposal No.: N071-094-0319 Firm: Sienna Technologies, Inc. 19501 144th Avenue NE Suite F-500 Woodinville, Washington 98072-4423 Contact: Ender Savrun Phone: (425) 485-7272 Web Site: www.siennatech.com Abstract: Conventional dielectric materials for hypersonic radome and window applications exhibit a number of performance limitations including inadequate thermal shock resistance, variations in electrical (dielectric constant and loss) and structural performance (mechanical strength) with temperature, and difficulty in fabrication to the desired shape. We propose to develop high strength, high toughness, high temperature stable, low dielectric constant continuous fiber-reinforced ceramic composites with wide band-pass in the L band (1-2 GHz) for GPS navigation and guidance, S-Ku (2-18 GHz) band for wrap-around antenna, and W band (94 GHz) for terminal homing for hypersonic window and radome applications. The Phase I program will fabricate a fiber-reinforced ceramic composite with the required electrical and mechanical properties for hypersonic windows and radomes. Equibiaxial flexural strength and thermal shock resistance of the composite disks will be measured up to 1500�C, and Weibull parameters will be calculated to determine their reliability. Free-space microwave dielectric properties, dielectric constant and loss tangent, between 75 GHz and 100 GHz will be measured up to 1500�C. Benefits: The proposed ceramic composite radomes and windows will be capable of protecting sensors at speeds of 4 Mach to 6 Mach at altitudes greater than 40k ft at cruise for at least 15 minutes over a wide frequency band from 1 GHz to 94 GHz. Damage tolerant, durable, multi-spectral, wide band windows would find a wide range of applications in both military and civilian applications. Military land, sea, and airborne vehicles that need GPS guidance and/or radio frequency altimetry, and commercial aircraft and high end automobiles that need collision avoidance systems would benefit from the new low cost, durable mullite composite windows. Commercial applications include the high temperature insulators such as ion plates for semiconductor process equipment where both mechanical strength and dielectric strength at high temperatures (>1000�C) are important. Return