GaAs And GaN Capabilities On Display At Farnborough

By Asif Anwar

The UK was host to air shows recently with the annual Royal International Air Tattoo (RIAT) and the biennial Farnborough International AirShow (FIA) 2014. I had the opportunity to attend a Lockheed Martin F-35/F-16 preview day held at RAF Fairford, the venue for RIAT, as well as taking a few days to attend FIA 2014.

At Farnborough 2014, there were long security lines to get in initially, but it was worth the wait as the show provided an interesting insight into the GaAs and GaN capabilities being offered — especially from a European perspective.

Finmeccanica

As an example, Finmeccanica’s group of companies were showcasing capabilities ranging from platforms to enabling semiconductor technologies.

• Thales Alenia Space had a display showing X-Band T/R modules (Figure 1) used on the SAR antenna of COSMO-Skymed satellite constellation. The T/R modules use both GaAs and GaN devices, produced at the units’ internal foundry.

X-Band T/R module

• Selex EW also has its own GaAs capabilities using an internal foundry based in Rome. These form the basis for radar systems such as the Kronos C-band Grand Mobile AESA radar, which combines a GaAs-based AESA radar with mechanical rotation (typically around 1 rpm), and is available in versions targeting naval and land applications. A company representative indicated that GaAs remains the primary technology of choice, though there is a roadmap towards using GaN technology.
• Also on display was the Selex ES Raven ES-05 GaAs-based AESA radar (Figure 2) used on the Saab Gripen NG. To increase the field of regard beyond the conventional capabilities typically offered by an AESA radar, the radar is positioned at a cant angle using a swash plate that allows the radar to rotate and provide a wider field of regard. According to a company representative, Selex ES uses a former RFMD/Filtronic facility, now owned by Compound Photonics (ex-Filtronic), as a foundry for its GaAs requirements.

Raven ES-05 GaAs-based AESA radar

• Another system enabled through solid state technology is the Seer (radar warning receiver) RWR which has been down-selected for Puma and Chinook helicopter platforms and is also suitable for use on fixed wing platforms such as fast-jets and UAS.
• Finmeccanica’s outdoor exhibition featured platforms such as the Falco UAS, which uses the the AESA PicoSar radar that features SAR imagery as well as GMTI capabilities. The Falco Evo, meanwhile, uses a mechanically scanned radar for maritime SAR use.

W. L. Gore

W. L. Gore has developed a simulator to help engineers address potential problems related to stress prior to installation. The Cable Installation Simulator is designed to evaluate the stress of installation on microwave airframe assemblies. New cable assemblies are tested to verify the insertion loss and VSWR over a given frequency range and serve as a baseline before being stressed by the simulator and re-measured to make sure they will continue to operate to specifications.

At Farnborough 2014, W. L. Gore announced the release of the company’s new GORE-FLIGHT Microwave Assemblies, 6 Series. Key characteristics include:

• The ability to maintain a consistent impedance of 50 ± 1 ohms
• Provide excellent VSWR characteristics
• Maintain insertion losses at the same level once assemblies have been cascaded or routed through airframe bulkheads

This is designed to reduce total ownership costs as the microwave assemblies are able to withstand problems during installation that can cause costly production delays. They can also lower the frequency for field servicing and reduce the need for purchasing replacement assemblies.

The 6 Series has been qualified to the stringent specifications required for airframe assemblies, with proven compliance with MIL-T-81490 requirements. Typical applications for the GORE-FLIGHT Microwave Assemblies, 6 Series include:

• Airborne electronic surveillance/counter measures
• Radar warning (electronic defense) systems
• Missile approach warning systems
• Radar interconnects
• Electronic/signal intelligence
• Navigation/communication systems

Gore’s microwave assemblies take advantage of the company’s in-house vertical manufacturing capabilities from purchasing raw materials, creating and applying the proprietary dielectric material, and then testing and shipping the final cable assembly. Interestingly, the view from the floor was that W. L. Gore solutions are not necessarily more expensive than other solutions but are on par with the upper echelon of cable providers, so emphasizing total cost of ownership advantages will help the company differentiate itself from competitors.

Mitsubishi Electric

The Japanese Aerospace Industry Pavilion featured a number of companies, including Mitsubishi Electric, showing systems as well as the company’s GaN device capabilities which range from VHF to Ku band application requirements.

Some examples included:

• A GaN-based C-band SSPA, designed to be a replacement for TWTAs
• GaN-based T/R modules and high power modules
• A SSPA targeting use in space

Unlike some of the company’s other Japanese competitors, e.g. Fujitsu (who were not exhibiting at Farnborough 2014), the feedback from the company’s representatives on the stand was that while the company will continue to be involved with Japanese  defense programs, the company has no intentions of targeting international defense opportunities.

Elettronica

The use of phased array technology extends beyond radar, and Italian company Elettronica was highlighting the company’s GaAs-based Virgilius active passed array system, which offers both ESM and ECM capabilities. The system has been selected for use on the Eurofighter and the company is also developing an EH-101 version for the Italian air force.

L3 Communications

At the L3 Communications chalet, there was a number of business groups represented.

• L3 TRL was demonstrating network security capabilities with the Catapan series of devices that leverage over a decade of experience in developing and supporting IP encryption. The mini-Catapan was on display, which enables encryption to “top secret” while offering 100 Mbps data rates. Cheaper, “loseable” export versions are also being introduced, offering AES 256 encryption, as well as offering commercial variants that focus on delivering up time.
• L3 Wescam was highlighting increasing focal lengths (to 300 mm) of its camera solutions with live feeds being demonstrated from a 10 inch turret. Other features include an internal IMU to ensure stability when installed on airborne platforms. Support products include simulator/emulator capabilities to support training. While competitors have brought other capabilities into their product portfolio, e.g. radar, L3 Wescam has the luxury of relying on other groups within the L3 family for other technologies, so they can maintain a focus on leveraging a strong market share position in its existing market.
• On the platform front, L3 was highlighting the King Air 350-based SPYDER II designed to leverage the company’s Rapid Aircraft Payload Deployment System (RAPDS) modular payload system. RAPDS includes a universal bus, cabling and adapters/connections to allow sensors, and antennas and mission systems to be swapped between combat sorties in a matter of hours, allowing users to execute a wide range of missions with a single platform. Naturally, the platform features a high L3 content, including data links, cameras, and data management systems.
• Also highlighted was the Bombardier Dash 8 Q400-based solution featuring auxiliary fuel tanks and a multi-mission reconfigurable payload system sitting underneath the aircraft. The platform will feature a high UK industrial content with sensors from companies such as Selex (e.g. the Selex ES Seaspray 7500E maritime surveillance radar) and Ultra Electronics as well as the L-3 Wescam MX-20 EO/IR turret, and a wide area airborne surveillance (WAAS) sensor. The platform is designed to provide high capability coupled with low whole life costs and could be used to fulfill maritime patrol requirements. The development aircraft has gone through flight testing and is working towards integration of fuel tanks and payloads. The company expects the STC (supplemental type certificate) process to be completed in 2015, which will clear the aircraft’s major modifications for use in civilian airspace.

International Rectifier

Other technologies being showcased at Farnborough included International Rectifier’s Hi-Rel battery storage technology. Designed to support military ground vehicles and UAS, the lithium ion batteries incorporate a management system that makes sure cells discharge equally. The solution is being used by the U.S. military and are also offered to international customers.

Saab

Finally, Saab stole a lead on U.S. competitors with the Saab Gripen (Figure 3) which was on display. As highlighted above, the Gripen NG features a Selex ES GaAs-based AESA radar as well as GaN technology built into jammers and EW passive warning systems built into the wing tips. The Saab Gripen NG is expected to enter service in 2018.

Saab Gripen