Low-profile military antennas could replace current models

Large antennas used by the military could be replaced with low-profile, broadband antennas.

‘One of the problems that many military communications systems have is that they use low frequencies — anywhere from 2MHz to less than 1GHz,’ said Nader Behdad, an assistant professor of electrical and computer engineering at the University of Wisconsin-Madison. ‘As a result, very often you see huge antennas sticking off of their vehicles.’

Behdad’s proposed approach to antenna design would see large dipole antennas replaced with a more compact and conformal multi-mode radiator.

He has been awarded a three-year, $510,000 (£325,000) research grant from the US Office of Naval Research to develop the next-generation antennas for its vehicles.

Behdad’s concept involves tuning multiple parts of the same antenna structure to radiate at different frequencies, using synthetic meta-materials to shape their radiation patterns so that they won’t interfere with one another.

Composed of metals, dielectrics and other materials, meta-materials react to electromagnetic waves differently, based on their index of refraction, making it possible to manipulate two competing radiation patterns and make them work in tandem within one antenna.

Behdad estimates that an antenna with dimensions of 20 x 20 x 3cm could operate anywhere between 200MHz and 40GHz in a design that could be flush with the vehicle’s surface.

Behdad believes that his project has broader commercial implications. ‘Any wireless application that uses different, widely varying frequency bands could potentially benefit from this technology,’ he said.