DAIMLER-BENZ Aerospace (DASA) has overcome persistent problems with the Eurofighter EF2000's ECR90 radar by modifying the antenna design.
According to DASA airborne-systems division vice-president Manfred Jacobsen, the radar suffered radome-compatibility problems, leading to "backflash".
The high-energy emissions from the antenna were being partially reflected into the ground by the inside wall of the radome, and were echoing back up to the aircraft. This "-destroyed the pulse-Doppler performance [of the radar]", says Jacobsen. The company has solved the problem by redesigning the antenna, changing the earlier, vertical polarisation to horizontal, he adds.
The situation was made more critical by an 18-month delay - caused by management and technical errors - in the delivery of the EF2000's glassfibre-reinforced-plastic radome. The problem was therefore identified late and, when initial tests showed that the radome could not be improved further, it was decided to modify the radar.
DASA intends to fly the ECR90 in the fifth EF2000 development aircraft on 5 November. Flight tests for the past three years have been carried out with the radar mounted on a BAC One-Eleven testbed.
The company will now concentrate on certificating the most important of the radar's 31 operational modes, to meet necessary maturity criteria before the Eurofighter production-investment decision, due at the end of this year. Development of the radar is expected to be completed in 1999.
The EF2000 radome was designed by British Aerospace, with elements of production and test work scattered among AEG in Germany, Alenia in Italy and CASA in Spain. Jacobsen says that pulse-Doppler technology has made the radome a critical item in radar procurement, concluding that "-it would be advisable in future to place both [radar and radome] contracts with one company".
DASA is part of the GEC-Marconi Avionics-led Euroradar consortium which developing the ECR90 with Italy's Fiar and Spain's Enosa. Senior design responsibility for the radar, which initially lay with DASA, was handed over to BAe this year. The ECR90 is an X-band radar, with multi-mode look-up/look-down and multiple-target-tracking capabilities.