Embedded Avionics, Military

Jammer Next

By By Bill Carey | September 1, 2010
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With the award of technology maturation contracts to four industry teams in July, the U.S. Navy NextGen Jammer (NGJ) program within two years will advance from competing concepts to prototypes of the electronic warfare sensor of the future.

ITT Electronic Systems in Clifton, N.J.; Raytheon Space and Airborne Systems in Goleta, Calif.; Northrop Grumman Integrated Systems in Bethpage, N.Y., and BAE Systems Information and Electronic Systems Integration in Nashua, N.H., each received $42 million contracts for the technology maturation phase, due to be completed in April 2012.

The same four contractors and industry partners participated in technology maturation trade studies awarded by the Navy in January 2009.

The NGJ is intended to counter advanced, integrated air defenses, communications systems, datalinks and non-traditional threats. “Pretty much any electronic or RF system, any antenna is a potential target,” said one program participant. The NGJ will replace the long-serving and continuously updated ALQ-99 Tactical Jamming System on the Navy’s EA-6B Prowler and EA-18G Growler electronic warfare aircraft. The Growler jams threat systems with up to five ALQ-99 pods mixed on underwing pylons to cover different frequency bands.

With the EA-6B being retired by 2012, the modular NGJ will enter service on the Growler first, the F-35 Joint Strike Fighter eventually and possibly a future unmanned aircraft platform.

The competition to build the NGJ is spirited. Northrop Grumman upgrades Prowlers with the Improved Capability (ICAP) III jamming system, and served to integrate the airborne electronic attack subsystem of the EA-18G.

“From a corporate perspective, we have been in the airborne electronic attack business for over 40 years. So Northrop Grumman and prior to that, Grumman, has a legacy in this mission area,” said Maris Lapins, the company’s NGJ program director.

“So if you ask the question, how important is it to us? It’s very important. It’s not something that we would readily give away to someone else. We’re going to compete aggressively to maintain our position in this mission area.”

On Growler, the NGJ transmitter will work in concert with the two primary receive functions on the platform: the Northrop Grumman ALQ-218 wideband Tactical Jamming Receiver, which geolocates emitters to cue jammers; and the Raytheon ALQ-227 Communications Countermeasures Set, a digital receiver/exciter that uses the ALQ-99 pod Low-Band Transmitter for communications jamming. Other components of the electronic attack suite include an ITT-produced Interference Cancellation System (INCANS) that provides UHF communications capability during low-frequency jamming.

The aircraft can be variously armed with the air-to-surface AGM-88 High-speed Anti-Radiation Missile (HARM) and AIM-120 Advanced Medium Range Air-to-Air Missile (AMRAAM).

Flyoff Follows

The NGJ program’s technology maturation phase will be followed by technology development, a competitive prototyping phase or fly-off involving just two contractors. After this phase, the Navy will choose a single vendor for engineering and manufacturing development and, eventually, low-rate initial production. The NGJ is expected to begin operations with the EA-18G fleet in fiscal 2018. While part of the ICAP III jamming system flying on the latest EA-6Bs, the legacy ALQ-99 first entered service in 1971, based on 1960s technology. Capt. John Green (left), commander of the Naval Air Systems Command (NAVAIR) PMA-234 Airborne Electronic Attack and EA-6B Program Office, explained the rationale for the new jammer.

“The ALQ-99 debuted just about 40 years ago, about the same time as the Prowler,” Green noted. “It has grown immensely over the years; we’ve upgraded virtually every component inside this podded system, the part that you see hanging on the wing stations of the aircraft. … Traditionally, we were always an IADS (Integrated Air Defense System) jammer. It was built to do that; it was very capable of that, but over the years we needed to jam other things like communications systems and datalinks and some non-traditional threats that we go after today. Where we have run into trouble is with some of the newer SAM systems. They have become much more capable in this age of networked systems and very fast electronics. They have a lot of counter countermeasures now on these radars and other system components that are beginning to exceed the capability of the ALQ-99.”

The podded NGJ system is expected to employ multiple electronically scanned arrays, consisting of thousands of transmit/receive modules, that combined will provide a wider field of regard than currently available on F/A-18E/F Super Hornets, EA-18G Growlers and Air Force F-22 Raptors equipped with active, electronically scanned array (AESA) radars. Electronically scanned radars have an effective field of regard of about 120 degrees for each planar array.

“The bringing of a broadband, electronically steerable antenna set is really the tipping point within this picture,” said Eduardo Palacio, ITT Electronic Systems vice president of programs. “[It] provides the agility in (radar) beam, not only in steering but in beam shaping and the number of beams that makes this a truly capable system over many, many years to come.”

The competing industry teams have been reserved in discussing their antenna concepts for the NGJ. However, Palacio added, “It’s safe to say that there’s no such thing in today’s technology as a single array that can cover the totality of frequency spectrum that needs to be covered, so everyone will build multiple arrays to fulfill the mission.”

In addition to the Navy work, ITT has received more than $50 million in Air Force funding to develop phased arrays, and has been working the issue for several years, he said.

While contractors were still working on draft requirements for the NGJ, “what we’re talking about here is basically a continuous wave kind of duty cycle, AESA array that’s not typically radar. We are adapting radar technology to a jammer,” said Chris Falco, Northrop Grumman chief engineer.

“When you integrate this into a platform like an -18G or even an F-35, the concept would be to also augment the system with the radar that’s on that platform. Obviously, that radar will have some limitations in terms of field of regard and transmitter duty cycle, but there are some radars it could be effective against. We’re definitely exploring AESA technology.”

In an email response, Steve Morais, BAE Systems director of attack solutions, said the “NGJ’s requirements call for antenna concepts which differ from conventional AESAs. We are advancing low-profile, electronically steered arrays which support wide bandwidth, high duty cycle operation and are compatible with SWAP (size, weight and power) constrained pod installations.”

Raytheon sees competitive advantage in that it already supplies the APG-79 AESA radar for the F/A-18E/F Super Hornet and Growler, as well as AESA radar solutions for the F-15 and F-16. It has a tradition of supplying jamming transmitters used in the ALQ-99 pod, having manufactured 1,200 used in the EA-6B and Air Force EF-111 Raven, which was retired in the late 1990s.

“This is an intensely competitive program with four very capable companies,” said Jim Bailey, Raytheon NGJ capture director. “The difference is that Raytheon has a 40-year legacy in making active arrays, and we have an extensive production facility. We’ve probably made more transmit/receive modules than any other company. We’ve fielded high-power active arrays that are operational, and that are operational in the maritime environment of an aircraft carrier. That puts us in a (good) position to be able to implement an active array for NextGen Jammer.”

Technology ‘Enablers’

Along with electronic scanning arrays, other critical technology areas or “enablers” identified for the NGJ are exciters, which optimize jamming signals, beam formers, high-power amplifiers and power generation, said NAVAIR’s Capt. Green. Power for the ALQ-99 jamming system is provided by a Ram Air Turbo-Generator (RAT) signified by four blades at the front of the pod.

“That’s been a very low-tech solution to providing power in the past,” Green said. “As we transition to arrays, we really need to be able to look out the front and sides of that pod, and we’d rather not have that view hindered by a RAT. We are looking at some advanced RATs that would be internal to the pod itself, with air scoops and the ability to remove some of the heat.”

Green added, “We’re looking at other, internal-to-the-pod types of things like exciters and beam formers and high-power amplifiers. Some of the big challenges that we’ve got with all three of those components are really speed and power. We know that in order to be effective against a lot of these, not only current high-power radars but also future radars, we need to be very quick and we need to handle a lot of power. That is an area where we are spending a lot of time focusing, and we’ll be asking industry to focus during technology maturation, on how do we make these things faster, how do we hook them up end-to-end and ensure that we remove heat efficiently, that we handle a lot of power. When you’re generating a powerful jammer that’s got to jam long distances and really be able to focus power very intensely, it’s all the more important that you be able to handle large amounts of power and heat.”

Similarly, industry teams cite the challenges of power generation, thermal management and packaging density in building the NGJ.

“The ultimate limiter to the system is going to be thermal management. We generate all this power, and things get hot,” said Raytheon’s Bailey.

“The current (ALQ-99) pod has a number of different transmitters fore and aft. We’re going to increase the level of capability of this pod to address many of those subsystems all at once.”

BAE Systems’ Morais said his company is addressing technology maturation “through our team composition,” bringing together partner companies with capabilities matched to critical technology areas. GE Aviation, supplier of the Growler’s twin F414-GE-400 turbofans “presently generates every watt of energy on the EA-18G and brings mature capabilities to power generation and cooling challenges,” he wrote.

“Cobham brings significant experience and capabilities in high-power transmitters, while Harris is contributing with expertise in electronically steered arrays. BAE Systems has relevant mission systems development and integration experience from our key programs, such as the (Air Force EC-130H) Compass Call and the Joint Strike Fighter. We are starting with a strong technology baseline across all technology areas and are maturing these concepts through the recently awarded NGJ Technology Maturation program,” Morais said.

Northrop Grumman is performing independent research and development on digital exciters and beam formers in Bethpage, and it produces high-power, broadband amplifiers based on gallium nitride (GaN) semiconductor technology at its Space Park facility in Redondo Beach, Calif. Among other companies, it is working with Mainstream Engineering, of Rockledge, Fla., on power generation and airborne system testing with Scaled Composites of Mojave, Calif.

Boeing, prime contractor in building airborne electronic attack capability into the two-seat F/A-18F Super Hornet, spawning the Growler, has teamed with ITT in pursuing the NGJ program. ITT will provide the phased array antennas, exciter and other electronic warfare components; Boeing is responsible for power generation, cooling, the pod structure and weapons system integration.

“For us, the meat-and-potatoes challenges are getting a lot of power and a lot of cooling in a very small package that is also light weight and low drag, so it integrates well with the platform,” said Rick Martin, director of Electronic Warfare Solutions with Boeing Phantom Works, based in St. Louis. “You’ve got to get the form factor down, you’ve got to make sure it integrates aerodynamically, structurally, that it integrates into the weapons system, [the] data fusion and crew vehicle interfaces — everything that takes you from a pod sitting on the shelf to a full-up electronic attack weapons system. All of those things need to be worked. This pod is new, different, more capable.”

Having successfully converted the Super Hornet into the EA-18G Growler, now the Navy’s premier electronic warfare aircraft, Boeing is well positioned for the NGJ selection, Martin said.

“We know what it took to take a proven Block II Super Hornet and what was at the time a developed electronic attack suite and put those two pieces together into a new system,” Martin said. “It took over a billion dollars and six years to get that job done. Even then, we had (the Department of Defense) telling us this was high-risk. For another (aircraft) program to come along and attempt to fill that role, it’s going to take billions of dollars, and I would argue many more years because the stage will be less than we were with the Block II Super Hornet.”

Program Manager: Navy’s Long-Term Future Includes Super Hornet, Growler

Initial operating capability of the F-35C naval variant of the Joint Strike Fighter in 2016 will not hasten retirement of the U.S. Navy’s F/A-18E/F Super Hornets and EA-18G Growlers, according to the service’s program manager. The Marine Corps plans to begin operations with the F-35B short takeoff, vertical landing variant of the JSF in 2012, retiring older F/A-18 Hornets and AV-8B Harriers.

But the Navy’s larger, more capable F/A-18E/F Super Hornets and EA-18G Growlers will complement the F-35 well into the future, said Capt. Mark Darrah, NAVAIR F/A-18 and Growler program manager.

“A lot of times we get questions about — what’s going to happen when the Joint Strike Fighter gets introduced to the fleet? The bottom line is, the Joint Strike Fighter is a legacy Hornet replacement,” Darrah said July 20, during a Farnborough Airshow briefing. “The Block II Super Hornet and the EA-18G are going to be in the fleet well into the (2030s) and we expect that those aircraft will be flying side by side.”

The program of record for the Super Hornet calls for 515 aircraft, Darrah said. The requirement for the Growler is 114 aircraft, which has grown from 88 two years ago to cover the expeditionary warfare requirement being filled by the EA-6B fleet, Darrah said. The Navy and Marine Corps have 620 legacy A through D-model Hornets in the fleet. The Royal Australian Air Force has taken delivery of 11 F/A-18F Super Hornets, with 13 more to be delivered by the end of 2011. There are more than 400 legacy F-18s operated by allied nations.

Darrah said more than 30 EA-18Gs have been delivered to the U.S. Navy fleet, and three squadrons have transitioned to the new aircraft, including a training squadron. The Growler achieved initial operational capability in September 2009; its first deployment will be this year. “The EA-18G took the very capable electronic attack, receiving system that was on the ICAP III Prowler, integrated that onto the wingtips; took the gun out of the fore-bay and replaced that with the avionics, and then integrated the ALQ-99 tactical jamming system pods, the pods that hang off the wings,” Darrah said.

Among other enhancements, he cited the ITT-made INCANS system. “The interference cancellation system we’re very excited about,” he said. “Something that was a very significant limitation to the EA-6B Prowler was that when you turned on your low-frequency jammers, you self-jammed yourself. You could not communicate, either transmit or receive. What we were asked to do was to find a way to isolate the frequencies we were communicating on. … This is a huge situational awareness tool for us, so that (pilots) can hear what’s going on (during) the jamming mission.”

Both the Super Hornet and the Growler are enabled by the APG-79 AESA radar. Raytheon recently delivered the 200th radar to the fleet, and the Navy has logged 150,000 flight hours with the APG-79, Darrah said. “As a radar, it’s a force multiplier,” he said. “What we’re able to do is use the AESA radar to designate, via SAR (synthetic aperture radar) map, precision coordinates that are then passed through Link 16 to non AESA-equipped aircraft.

“So what we’re doing is flying mixed sections,” Darrah explained. “I can have one AESA-equipped Super Hornet in a section of six aircraft, five of which can be legacy airplanes. I can use the precision capability of the AESA radar and Link 16 to send data offboard to the non AESA-equipped aircraft, and they’re able to deliver Joint Direct Attack Munitions or precision weapons to those targets without ever having to use their radars. They can be radar silent during this whole time.” —Bill Carey

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