Somewhere deep in America, scientists are developing a sophisticated defence system to protect their country from a repeat of September 11.

Never before has the world's biggest superpower felt so at risk to an act of terrorism.

And, for one cutting-edge Bradford company, it could bring about a dramatic boost in its economic fortunes.

Filtronic Plc, based in Saltaire, is anticipating huge growth in its electronic warfare sector in the next 12 months.

The firm, a world leader in microwave and millimetre-wave electronics, is best-known for designing antennas for mobile phone handsets.

But it has increasingly become responsible for some of the world's most advanced components for defence systems.

The firm has already secured a contract to supply the new generation European Fighter Aircraft with technology that can protect it from enemy missiles.

And now it is anticipating increasing demand from the US as its defence chiefs look to strengthen its protection system.

One possibility is that the country's landmark buildings could be fitted with similar high-tech anti-missile protection systems to those Filtronic supplies for fighter jets and warships.

Professor David Rhodes, pictured, chairman and chief executive of Filtronic, said the firm believed rapid technological advances driven by its world-leading engineers had sparked fresh interest in defence technology.

It is the kind of equipment which was used in the Gulf War to enable "smart" missiles to pinpoint targets with incredible accuracy from hundreds of miles away.

"We see defence as the future underpinning of the company," he said.

"We can see 25 to 30 per cent growth, and pretty profitable growth at that. It is the one area we can be absolutely sure of. Demand has gone up in the States recently, and that reflects the way it has tended to go in cycles. But we haven't suddenly got new technology just because of September 11.

"It is a much longer term effect. It has been ongoing for some time and it has been accelerated by the technological change which, in the last ten years, has been dramatic."

Prof Rhodes said the days of combating a nuclear threat with an equivalent nuclear threat had been succeeded by a fresh willingness to look at defence. And he said the US Government's examination about how it could best defend its country reflected the new thinking.

About 80 Filtronic employees are permanently stationed in the US working on projects for the American Government that are so top secret even Prof Rhodes is not allowed to know what they are up to.

And he expects other countries to follow the American lead.

"I would not be surprised if we did that in this country because all you have to get is one mad man in the world with the capability to do the damage and you have had it," he said.

And those countries are likely to look to Filtronic for the expert knowledge.

Prof Rhodes said the depth of knowledge at Filtronic was unrivaled, with the firm being the world's sole provider of much of the latest technology.

"We have some extremely talented people and we have 25 years' background in this field," he said.

"It's not the kind of thing you can acquire overnight. This knowledge is not freely available.

"I have never made money in defence until now because we have never had the production levels to make it profitable. Now that is changing and we have intellectual property that is pretty unique."