Northrop Grumman Corp. will help the US Air Force enhance the surveillance capabilities of aerial vehicles by embedding antennas in the primary load-bearing structures of composite aircraft wings. The new approach could lead to antennas as large as the surface area of a wing with enough sensitivity to simultaneously detect ground-moving targets through dense foliage and track air-to-air missile threats.

Northrop Grumman and the Air Force Research Laboratory will share the costs of maturing the antenna integration technology under a five-year, $12 M effort called the Low-band Structural Array (LOBSTAR) program. The effort could benefit unmanned aerial reconnaissance systems such as the Air Force’s Global Hawk, the Defense Advance Research Agency’s Joint Unmanned Combat Air System and the Air Force Research Laboratory’s future Sensor Craft concept. “Conformal load-bearing antenna structure (CLAS) technology converts otherwise passive structures, such as a wing, into a system element that increases avionic performance and reduces airframe weight and cost,” said Allen Lockyer, Northrop Grumman’s LOBSTAR program manager. “It also allows us to implement mission functionality that simply would not be possible using conventional antenna technologies.” Northrop Grumman has previously used CLAS technology to increase the functionality of other passive aircraft structures such as the tail and the fuselage, he added.

The LOBSTAR program represents the first government-funded application of CLAS to low frequency radar and large primary wing structures. The large surface area dedicated to the antenna provides the needed gain and coverage to detect slow moving targets masked by heavy jungle foliage, a task that has been previously deemed impossible with conventional antennas. Northrop Grumman’s LOBSTAR contract includes a scale-up phase that will test the limits of a five-element-by-five-element structural antenna subarray developed during the company’s S-CLAS program, a precursor program to LOBSTAR, and a flight test phase to evaluate the performance of that array in a BAC 1-11 test bed aircraft against real targets. To date, the company has demonstrated that the S-CLAS test array can sustain peak loads of 10,000 pounds per inch. Northrop Grumman’s Integrated Systems sector will lead the LOBSTAR effort with overall program structural design and material manufacturing responsibilities.