Durable & Removable Mast Appliqus for Tunable Radio Frequency Absorption

US Navy submarines use metallic masts such as Lockheeds OE-538/BRC Multifunction Communication Mast Antenna System to communicate. Although these are highly effective, a main drawback to their use is that they can be detected by enemy radar. A prospective solution would be the application of material over existing masts that can be tuned to keep any desired band open for communication while maximally absorbing all other frequencies. This material must be environmentally stable to temperature/pressure changes, salt corrosion, and humidity. Additionally, since the mast assembly cannot be removed, the coating/material must be applied on the submarine. Luna proposes a multilayer adhesive appliqu, with different sheets tuned to specific open frequency bands. The individual layers will contain tunable fillers and/or structures to maximally absorb unwanted frequencies while retaining the desired frequency band open. With slight modification to the formulation, the appliqu can be tuned to different open frequency bands. Protective coatings will be applied to the sheets to achieve desired marine environmental protection. For the Phase I program Luna will combine experimental simulations, material synthesis, and radar cross-section/absorption testing, with the primary goal of demonstrating feasibility of tuning performance to the open frequency bands.