Radio revolution

In an effort to improve the speed and quality of two-way radio communication,

researchers have developed a self-adapting antenna for cognitive radio. This is a form of wireless communication in which a transceiver detects which channels are in use and which are not.

Dr Peter Gardner said the team is one of the first to try advances in the area by changing a radio's antenna, rather than modifying the signal processing methods of cognitive radio.

'The concepts behind cognitive radio are so far coming from the world of software and electronics, and some of the assumptions that have been made about the way that antennae operate are perhaps not entirely correct.

'For example, you need a single, very broad band antenna that will cover a very wide frequency range. But if you have got a broad bandwidth, there are important trade-offs between bandwidth, size and efficiency,' said Gardner.

Signals in old-fashioned radios are tuned, modulating the frequency or amplitude so that the receiver can extract the information, using fixed analogue circuits.