Ohio State University researchers have developed technology to embed high-performance antennas directly into clothing. The OSU Research News acknowledges that fabric antenna are not new, but says the Ohio State system takes elements from this previous research and uses a computer control device that allows multiple antennas to work together in a single piece of clothing.
One of the problems that the OSU technology alleviates is the effect of the body on the antenna. The antennas are built on FR-4 plastic film which is sewn into fabric. For the tests, researchers placed the antennas at four locations on a vest: the chest, the back, and both shoulders. The computer-controlled combiner is a small metal box a bit smaller than a credit card and about an inch that's thick worn on the belt. In laboratory tests, the experimental antenna system provided significantly greater field strength as compared to a conventional military whip antenna. Researchers claim the system will provide four times the communications range achievable with the whip.
Some of that advantage comes from the omnidirectional coverage of the antenna vest. A key element of this technology was the engineers' development of network communications coding to coordinate the signals among antennas. Doctoral student Gil-Young Lee developed the computer module to automate the antenna control.
John Volakis, the Roy & Lois Chope Chair Professor and Director of the ElectroScience Laboratory at Ohio State compared their design with that in cell phones. "In a way, we're doing what's already been done on a cell phone. You don't see cell phones with external antennas anymore, because the antenna is part of the body of the phone."
Chi-Chih Chen, a research associate professor of electrical and computer engineering at Ohio State said, "Our primary goal is to improve communications reliability and the mobility of the soldiers. But the same technology could work for police officers, fire fighters, astronauts--anybody who needs to keep their hands free for important work."
Chen estimated a system similar to the vest antenna demonstrated would cost about $200 per person and mass production would make the cost significantly lower. Current research includes printing the antennas directly onto clothing and embroidering antennas into clothing using metallic threads. This could make it useful for the general public as well. Perhaps embroidered vest antennas will be next fashion accessory for smartphone and tablet users! Volakis sees this as a possibility. While scrunching a sample of embroidered taffeta in his hand he said, "Imagine a vest or shirt, or even a fancy ball gown made with this technology. The antennas would be inconspicuous, and even attractive. People would want to wear them."
The larger antennas would also improve reception of VHF mobile DTV stations!
The research is described in detail in an article by Lee, Chen, Volakis and Dimitrios Psychoudakis, senior research associate at the OSU ElectroScience Lab, in the current issue of IEEE Antennas and Wireless Propagation Letters.
