Low Cost Durable EMI Screen for Aircraft Infrared Sensors

In certain aircraft, sensor apertures are too large to cover with an infra-red (IR) transparent window and these apertures are covered with an electro-magnetic interference (EMI) screen. The F-117 Stealth Fighter is an example of an aircraft with such a screen. This screen is prone to damage by rain erosion and environmental loads during flight. It consists of highly tensioned, hand woven stainless steel wires mounted on a rigid frame. Under environmental loads, wires in this screen have a tendency to break. Once a wire is broken, other wires in its vicinity loose tension and the screen begins to unravel under aerodynamic loading. During the Phase I program, Surmet demonstrated a mesh which is etched from a single sheet of steel. This etched mesh is more durable than its woven counterpart, and will not unravel if it is damaged. During the proposed Phase II program, the etched mesh will be transitioned from the laboratory onto the flight line. Working closely with Lockheed Martin, Surmet will test and evaluate etched mesh samples for mechanical, optical and RF performance. The program will culminate with the delivery of full scale hardware for flight test evaluation.