Computer-Aided Tool Based on Solid Models for Wrapping Periodic Elements onto Doubly-Curved Surfaces

The modern battlefield contains first-world foes that possess more sophisticated electromagnetic capabilities. For this reason, the surfaces of next-generation airborne platforms will make extensive use of planar periodic electromagnetic structures to radiate, detect, and manipulate electromagnetic waves. In almost all cases, it is desired to wrap the periodic structures over complex, irregular, and doubly-curved surfaces of these air-vehicle platforms. However, conforming periodic structures over such surfaces causes the patterns to become deformed, which alters or erases the electromagnetic properties. This seemingly impossible geometry problem was solved and patented by researchers on the Kraetonics team. Dramatic results were obtained that show the arrays wrapped over doubly-curved surfaces performed on par with flat versions of the same design. Given that a doubly-curved pattern is able to preserve its electromagnetic properties, the geometry is called a preservational spatially-variant lattice (PSVL).The Phase II effort will develop OmniFSS™, a complete software product that others can use to wrap periodic structures over doubly-curved surfaces and manufacture the designs via hybrid AM. The effort will focus on FSSs, but the tool is applicable to many other things such as metasurfaces and phased array antennas.