OBJECTIVE: The objective is to develop radar reduction technology for a panoramic imaging submarine mast that has multiple optical windows. DESCRIPTION: The Navy is developing a new panoramic imaging submarine mast which will be similar in size to existing submarine periscopes for which general information is widely available. (See Reference 1.) Current technology covers masts with radar absorbing material structure, allowing an unobstructed area for the optical window. The architecture of a panoramic mast is vastly different from the existing masts, and requires a new innovative approach to implement and improve this radar absorbing capability. There are two critical differences between the standard periscope mast and the new panoramic mast: (1) the panoramic mast has multiple windows, which will affect the structural integrity of the resulting radar absorbing material to be attached to the mast (with less surface area, it must be stronger than existing products which cover a whole mast), and (2) the panoramic mast has multiple windows which must have their individual signature contributions mitigated, providing a considerable challenge to develop a new capability over what is currently available. Existing state-of-the-art microwave absorbing technology includes various types of composites or coatings used for shielding against electromagnetic interference, antenna development and pattern shaping, and dielectrics. (See References 2, 3 & 4.) The Navy desires a solution that must provide radar vulnerability reduction for both the mast and the optical windows. It must remain attached while the mast is in the vertical position and raised above the submarine sail. It must be survivable while exposed to high pressure salt water for extended durations. Pieces mounted on the outside of the mast can be up to 3/4 inch thick, and pieces or coatings over the optical windows must be optically transparent. The product may be one physical piece, or multiple components (necessary, for example, if coatings on windows were used). The Phase I effort will not require access to classified information. If need be, data of the same level of complexity as secured data will be provided to support Phase I work. The Phase II effort will likely require secure access, and the contractor will need to be prepared for personnel and facility certification for secure access. PHASE I: The company will develop concepts for signature reduction technology that meet the requirements described above. The company will demonstrate the feasibility of the concepts in meeting Navy needs and will establish that the concepts can be feasibly developed into a useful product for the Navy. Feasibility will be established by material testing and analytical modeling. The small business will provide a Phase II development plan with performance goals and key technical milestones, and that will address technical risk reduction. PHASE II: Based on the results of Phase I and the Phase II development plan, the small business will develop a scaled prototype for evaluation as appropriate. The prototype will be evaluated to determine its capability in meeting the performance goals defined in Phase II development plan and the Navy requirements for signature requirements. System performance will be demonstrated through prototype evaluation and modeling or analytical methods over the required range of parameters including numerous deployment cycles. Evaluation results will be used to refine the prototype into an initial design that will meet Navy requirements. The company will prepare a Phase III development plan to transition the technology to Navy use. PHASE III: If Phase II is successful, the company will be expected to support the Navy in transitioning the technology for Navy use. The company will develop signature reduction technology for evaluation to determine its effectiveness in an operationally relevant environment. The company will support the Navy for test and validation to certify and qualify the system for Navy use. PRIVATE SECTOR COMMERCIAL POTENTIAL/DUAL-USE APPLICATIONS: Commercial use of this technology includes electromagnetic interference reduction in electronic devices, particularly mobile devices which have microwave transmitters. In addition, absorbing materials can be used to control antenna patterns in radar detectors or microwave communications devices (cellular or satellite). REFERENCES: 1. Kollmorgan Optronic Products, 2012,
2."Absorbing Materials", Microwaves101.com, 2012. . 3. Micheli, Davide; Apollo, Carmelo; Pastore, Roberto; Morles, Ramon Bueno; Marchetti, Mario; Gradoni, Gabriele,"Electromagnetic Characterization of Composite Materials and Microwave Absorbing Modeling", University of Rome, April, 2011. . 4. Stephan, Scott, Laird Technologies,"Microwave Absorbers: Common Uses and a Comparison", December 2008. .