The strategic importance of active array airborne radar technology in Europe cannot be understated, according to EADS Defence Electronics (Hall 2 Stand A151). The company has invested heavily in advanced transmit/receive (T/R) modules that have a variety of applications. The advantages of using T/R modules for airborne fire control, as well as airborne and ground-based surveillance are well recognized.

But according to Dr. Elmar Compans, the European group’s senior vice president sensors, more exotic applications, including conformal antennas, communications and electronic warfare could follow in the near term.

EADS first began working on e-scan radars in the late 1980s and continues today sustained since 1993 by funding from the tri-national airborne multirole solid-state active array radar (AMSAR) technology development program. EADS also set up a joint venture with Thales and United Monolithic Semiconductors (UMS) to develop transistors, diodes and integrated circuits using gallium arsenide (GaA). UMS now produces high-performance GaA semiconductors on a large scale for various defense and  telecommunications applications.     

Meanwhile, EADS made an independent investment in microwave technology, alongside the UMS facility in Ulm, Germany. In a 15,000-sq-ft “clean room” there EADS can manufacture up to 100,000 T/R modules per annum–enough for 60 to 70 radars. According to Compans, this is a strategic capability for Europe, since the U.S. will not export this technology.

These T/R modules produced in Ulm have already flown on a prototype E-scan version of the Captor radar for the Eurofighter Typhoon. They were also flown on the SOSTAR surveillance radar demonstration in 2006-07 and have gone into space on the EADS TerraSAR earth observation satellite that was launched in June 2007. The new truck-mounted tactical ground-surveillance radar also uses this technology. The German army is trialing it and EADS is offering it for export. The anti-ballistic missile radars for the medium extended air defence system will  include the T/R modules.

In the past two years, EADS has been developing the first semiconductors using gallium nitrate (GaN), a material that delivers much greater bandwidth and power output than GaA. When used in T/R modules on an active radar array, it allows for multiple applications. A frequency range from 1 to 20 GHz is achievable, so that the radar can also be used for communications, IFF and ESM (for example, electronic intelligence).

The power output (100w per module) is up to 10 times greater than that available from GaA, so the radar can be used for electronic warfare. Compans believes Europe is not far behind the U.S. in GaN technology.

EADS is also working on conformal antennas. In this application, the usual linear structure of the T/R modules is changed into a cube configuration, so they can fit on a curved surface. Compans said EADS has already produced conformal antennas for communications. This technology has obvious advantages in the design of low-observable air vehicles.

Compans also said that EADS Defence Electronics is well positioned as a leading supplier of active array radars. Unfortunately, some of the advances described here have not yet been approved for series production for an airborne application.

While Thales has received French government funding to develop an active array version of the RBE2 radar for the Rafale, NETMA has not approved funds for a production Captor E-scan radar for the Typhoon. And despite the successful SOSTAR demonstration, NATO opted to buy the American MP-RTIP radar off-the-shelf for the alliance ground surveillance system.