Supersonic air vehicles require nose radomes that can withstand high temperatures as well as have high RF transmission over wider radio frequency bandwidths. Typically nose radomes are built from monolithic, solid wall ceramic materials which inherently have a very narrow frequency band over which they are RF transparent. The proposed concept leverages a recently qualified ceramic matrix composite AS-N312 as the outer shell that will withstand the forces and environments. To achieve wider bandwidths, lower dielectric ceramic foam materials are added to the inner surface that act as impedance matching layers, enabling transmission of a broader range of wavelengths. The proposed designs avoid inclusion of an inner skin that would form a more traditional sandwich structure to prevent significant shear stresses from occurring in the ceramic foams. The study will: identify candidate foams, the methods by which they can be mechanically integrated to the radome shell, and provide test data on the RF transmission characteristics of candidate layered designs. Affordability is dramatically improved because AS-N312 is the lowest cost, qualified structural ceramic material available today, and the processes to achieve other attributes such as erosion protection and EMI filters are also fully developed and cost effective.
Benefit: A nose radome that can withstand the supersonic environment and have broader bandwidth inherently allows the sensor designer and the mission planner more flexibility in design of the antennas that can be included in the nose radome. A broader bandwidth radome also implies larger manufacturing tolerances, because it will still transmit efficiently even if the as-built product is slightly de-tuned with respect to the optimal design. Larger manufacturing tolerances mean better affordability. Additionally, by using a material (AS-N312) that the US Navy has already qualified for a production program (AARGM), the non-recurring development costs are kept to an absolute minimum. Inclusion of non-structural foams also means that their qualification criteria will be less stringent, also keeping development costs low.
Keywords: wide bandwidth radomes, wide bandwidth radomes, Supersonic radomes, ceramic radomes, broad bandwidth radomes, ceramic foam, High Temperature Radomes
