Research may yield more compact antennas for military use

Dec 12, 2011 By Mark Riechers

(PhysOrg.com) -- While tall, bulky antennas seem like relics in an era of sleek, modern smartphones, they're still an unfortunate necessity for American soldiers.

"One of the problems that many military have is that they use low frequencies — anywhere from 2 MHz to below 1 GHz," says 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 thinks that those enormous antennas could be scrapped for low-profile, broadband antennas — thanks to a different approach to antenna design that replaces large dipole antennas with a more compact and conformal multi-mode radiator.

The Office of Naval Research agreed, giving Behdad a three-year, $510,000 research award through its young-investigator program, allowing him to develop the next generation of antennas for its vehicles.

With traditional dipole antennas, the lower the operating frequency of an antenna, the larger it needs to be. Rather than fighting the laws of physics and trying to lower the operating frequency of a single antenna, Behdad's concept involves tuning multiple parts of the same antenna structure to radiate at different frequencies, using synthetic "metamaterials" to shape their radiation patterns so that they won't interfere with one another. Composed of metals, dielectrics and other materials, metamaterials 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-by-20-by-3 centimeters could operate anywhere between 200MHz and 40GHz in a design that could be flush with the vehicle's surface. That combination of small size and a wide band of available frequencies makes Behdad's antenna design ideal for future military communications platforms, which will involve small and large devices operating over a wide range of frequencies.

But the implications for the military are even more important than preparing for a more connected future: Eliminating the large antennas from their communications equipment could also make U.S. soldiers safer.

"If you have something like a huge antenna sticking out of a soldier, it paints a pretty big target on them as they walk in the street," says Behdad.

Despite its very specific end goal, Behdad's project has much broader commercial implications. "Any wireless application that uses different, widely varying frequency bands could potentially benefit from this technology," he says.

Ultra-wideband wireless technology — which could power the next generation of wireless video and data connections for personal computers — could benefit greatly from the technology, as could telecommunications companies that will be looking for ways to best use the low-frequency bands that were vacated in the changeover to digital television.

Giving up those tiny, sleek smartphones for bulky UWB antennas isn't especially palatable for consumers, and Behdad's concept could be the answer to a coming design problem in the cellphone industry. "

"If you want to have a cell phone that works in these frequencies of 600 MHz or 300MHz, having compact antennas that are broadband would be useful," he says.

Explore further: Greater safety and security at Europe's train stations

add to favorites email to friend print save as pdf

Related Stories

Insect hearing inspires new approach to small antennas

Feb 28, 2011

(PhysOrg.com) -- Ormia ochracea is a small parasitic fly best known for its strong sense of directional hearing. A female fly tracks a male cricket by its chirps and then deposits her eggs on the unfortunate ...

NIST antenna calibrations extended to 60-110 GHz

May 25, 2007

The National Institute of Standards and Technology (NIST) has developed a new "tabletop" sized facility to improve characterization of antennas operating in the 60 to 110 gigahertz (GHz) frequency range. This extended frequency ...

Recommended for you

Greater safety and security at Europe's train stations

Sep 01, 2014

When a suspicious individual fleas on a bus or by train, then things usually get tough for the police. This is because the security systems of the various transportation companies and security services are ...

Fingerprints for freight items

Sep 01, 2014

Security is a top priority in air freight logistics but screening procedures can be very time consuming and costly. Fraunhofer researchers intend to boost efficiency with a new approach to digital logistics, ...

On the way to a safe and secure smart home

Sep 01, 2014

A growing number of household operations can be managed via the Internet. Today's "Smart Home" promises efficient building management. But often the systems are not secure and can only be retrofitted at great ...

DIY glove-based tutor indicates muscle-memory potential

Aug 31, 2014

A senior editor at IEEE Spectrum worked on a DIY project that enabled his 11-year-old son to improve his touch typing by use of a vibrating glove. His son was already "pretty quick on the keyboard," said ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Isaacsname
not rated yet Dec 12, 2011
What about printed thin film fractal antennas ?

http://en.wikiped...antennas