Robust Conformal RF Sensors

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Hypersonics OBJECTIVE: Design and demonstrate innovative RF conformal sensors utilizing advances in high-temperature materials and additive manufacturing capable of surviving and operating throughout exposure to the extreme temperatures and environments generated during hypersonic flight. DESCRIPTION: The government is seeking innovative solutions to enable the adoption of conformal, forward-looking sensors on high-speed platforms for a variety of capabilities. The challenging flight environment of hypersonic vehicles leads to conflicting requirements between maintaining mechanical and thermal survivability and ensuring effective RF functionality. This conflict results in either sub-optimal sensor performance or constraints on vehicle trajectories to protect the sensor. To overcome this conflict, advances in high-temperature materials and, especially, additive manufacturing seek to decouple mechanical and RF disciplines thus removing conflicting design requirements. Air Force is looking for breakthrough advancements in additively manufactured sensor technology to enable inclusion of robust, high-performance RF sensors on hypersonic vehicles. The selected approach will allow for sensors to be mounted directly on the outer surface of the vehicle minimizing Size, Weight, Power, and Cost (SWaP-C). The sensors must provide high-directivity radiation patterns and appropriate Field-Of-View (FOV) and Field-Of-Regard (FOR) to support a variety of sensing scenarios, while enabling all day, adverse weather, and high-resolution capability. Due to the wide variety of potential platforms, the proposed solution must also be compatible with integration into a variety of surface skin materials (alloys, carbon-carbon composites, etc.) and compatible with extreme surface temperatures (1000 C+). PHASE I: This topic is soliciting Direct to Phase II (DP2) proposals only. Therefore, Phase I proposals will not be accepted or reviewed. The offeror is required to provide detail and documentation in the Direct-to-Phase II proposal which demonstrates accomplishments commensurate of a Phase I-like effort, including at minimum, a feasibility study and preferably validation through an antenna prototype. This includes a review of the scientific and technical merit and feasibility of proposed ideas. The offeror should be able to show performance of a conformal sensor utilizing advance manufacturing techniques to achieve desired decouple of RF and mechanical requirements. Successful offerors will demonstrate a plan for the design, construction, and assembly of a robust sensor compatible with high-temperature materials and the extreme environments of hypersonic flight. For detailed information on DP2 requirements and eligibility, please refer to the DoD BAA and the AFRL Instructions for this topic. PHASE II: Actively demonstrate the innovative sensor approach by manufacturing prototype designs for laboratory and environmental testing. Evaluate the mechanical and thermal robustness of the design to representative thermal/mechanical loads. RF design tasks shall include: modeling and simulation of the sensor detailing RF performance (e.g. frequency band, bandwidth, directivity, efficiency, FOV, FOR, cross polarization isolation, sidelobe levels, etc.) within the SWAP constraints of the vehicle concept. Mechanical design tasks shall include: thermostructural analysis of sensor solutions for representative environments and design of a robust mechanical assembly with the ability to integrate into a variety of platform materials and geometries. Offeror shall work with the government to develop a concept of operations for various supported sensor modes as well as collaborate with platform integrators to facilitate the development of realistic sensor installation concepts. Technology maturation tasks shall include: fabrication and characterization of a conformal, sensor prototype using actual or surrogate materials. Fabricated prototype will be subjected to RF and environmental testing to validate sensor robustness and ability to maintain operation throughout exposure to representative flight conditions. PHASE III DUAL USE APPLICATIONS: Fabricate, characterize, and deliver working, high-temperature prototypes for integration into prospective flight vehicles and field demonstrations. REFERENCES: 1. Jenkel K-D, S nchez-Pastor J, Baloochian MM, Jakoby R, Sakaki M, Jim nez-S ez A, et al. Effect of sintering temperature on the dielectric properties of 3D-printed alumina (Al2O3) in the W-band. J Am Ceram Soc. 2024; 107: 2494 2503. https://doi.org/10.1111/jace.19597 2. Y. Lakhdar, C. Tuck, J. Binner, A. Terry, R. Goodridge, Additive manufacturing of advanced ceramic materials, Progress in Materials Science, Volume 116, 2021, 100736, ISSN 0079-6425, https://doi.org/10.1016/j.pmatsci.2020.100736. 3. Josefsson, Lars, and Patrik Persson. Conformal array antenna theory and design. Vol. 29. John wiley & sons, 2006. KEYWORDS: Sensor; conformal; additive manufacturing; advanced materials; hypersonic; high temperature