GaN Advances Boost Raytheon’s RF Stature
Aviation Week & Space Technology

Decades of work on producing a new semiconductor is paying off for Raytheon

An edge in developing and producing gallium-nitride (GaN) semiconductor material is behind Raytheon's hard-fought win of the U.S. Navy's Next-Generation Jammer contract and could set a benchmark for competitors seeking to take on the company in future sensor competitions, Raytheon officials say.

GaN circuits, housed on “wafers,” can efficiently amplify high-power radio-frequency signals at microwave frequencies. “GaN emits five times the radio-frequency power of the previous [gallium-arsenide] technology, a property that results in smaller, more affordable, more powerful and efficient electronic circuits,” says Joe Smolko, manager of advanced technology programs at Raytheon.

The Next-Generation Jammer (NGJ) contract win over BAE Systems and a Northrop Grumman/Excelis team was the first major capture attributed to Raytheon's advances with GaN, he says. It is also underpinning the company's design for the Navy's Air and Missile Defense Radar to replace the sensors on the service's Aegis fleet; Raytheon won against Lockheed Martin and Northrop Grumman.

Raytheon produces GaN circuits at its foundry in Andover, Mass., the only facility to earn a manufacturing readiness level of eight by the Pentagon. “This is the highest level obtained by any organization in the defense industry for this technology,” Smolko says.

The GaN effectively allows for shrinking sensor components and decreasing weight, key factors in fabricating an airborne pod. “The power efficiency of GaN is key to NGJ, so you can go to higher power and get within the [size, weight and power]” constraints of the pod, says Travis Slocumb, vice president of electronic warfare systems at Raytheon. The company has been working with the semiconductor material for about 15 years.

The Navy plans to introduce its new NGJ into the fleet on the EA-18G in 2020, although development has slipped six months because of a bid protest.

The service cleared Raytheon, which originally won the work estimated to be worth $7 billion including development and production, to restart technology development last month. Last July, BAE protested Raytheon's win of the $279 million technology development project. After reevaluating bids, the Navy announced Jan. 24 it will stick with Raytheon. The NGJ will eventually replace the ALQ-99, which has been used on the EA-6B Prowler and EA-18G Growler.

The 22-month technology development phase will focus on maturing systems for Increment 1, which includes the electronic-warfare capability against mid-band radio frequencies. “Increment 1 is the only funded program and covers the most critical threats,” says Capt. John Bailey, the Navy's program manager for Airborne Electronic Attack Systems and the EA-6B Prowler.

Increments 2 and 3, notional follow-ons for jamming of low- and high-band systems, respectively, are not yet funded, Bailey says. While the mid-band jammer can focus on such missions as standoff jamming of integrated air defense radars, the future increments also could address a variety of communications links. Increments 2 and 3 would be ready for operational use in 2022 and 2024, respectively.

Once approved, however, the Navy intends to conduct a “full and open competition” for these future increments, he says.

Increment 1 development is slated to begin in the second quarter of fiscal 2016, Bailey says, with production to follow two years later. The Navy plans to buy 228 pods, two each for 114 EA-18Gs.

The NGJ will bring significant advances over the ALQ-99's 45-year-old technology relying on traveling-wave tube and solid-state technologies, Bailey says. The Increment 1 NGJ will employ active, electronically scanned array (AESA) capabilities, providing improved power, jamming and beam steering. It also allows the jammer to address a higher number of targets than the ALQ-99.

One benefit of the new technology is targeted jamming; today's systems cause interference, effectively producing radio-frequency collateral damage. NGJ is designed to be a more elegant capability that can enable use of friendly systems while offering jamming of specific portions of the spectrum for an adversary's sensors.

During the technology development phase, Raytheon will develop a pathfinder pod on its own funding and fly it on a company-owned test aircraft.

Each subsystem—power generation, AESA arrays, exciters, cooling systems and structural components—will be tested in a relevant environment in order to verify it is sufficient to achieve a technology readiness level of 6 during the technology development phase, Bailey says. The tech demo will culminate in a preliminary design review, and wind-tunnel test articles will be built to support aero performance, stability and control test requirements.

Full-scale pod tests would follow in the development phase.

Raytheon is working under a cost-plus, incentive-fee contract, the use of which underscores the complexity of the work being done in technology development. The Pentagon recently has embraced fixed-price deals in an effort to reduce its financial exposure to cost overruns, but such contract types are not employed for programs requiring higher levels of invention. The contract incentives are focused on performance with the effective isotropic radiated power, cost, schedule and weight of the system, Bailey says.

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