High-Strength and High-Durability Radio Frequency (RF) Transparent Structures

CLAS Structures reduce the weight of conventional antenna systems by embedding the antennas into the load bearing composite structures. The Northrop LOBSTAR program is developing this technology for potential use on Global Hawk.This program proposes the use of a new core material developed by Aztex - K-CorT to provide a superior structural solution. CLAS structures require the use of less structurally efficient materials such as Nomex and lower modulus facesheet materials such as Astroquartz. Edge ramps and local densified areas require non-RF transparent potting compounds that degrade antenna performance. This results in lower structural efficiency and retains the inherent poor damage tolerance and environmental knockdowns associated with honeycomb. K-CorT consists of a structural array of pultruded rods in closed-cell foam. Core strength is based on the number and stiffness of the pins in the array. Properties are tailored locally to match the requirements. No potting compounds are required, truss pins extend throughout ramp transitions, local densification consists of higher density vertical pin arrays. Strength retention of impacted K-CorT is high and hot/wet properties are 92-100% of RTD. The K-CorT advantage is excellent damage tolerance, superior hot/wet capabilities, easily thermoformed and properties tailored to the requirements of the application.