Carrying around a heavy, bulky and conspicuous antenna backpack physically exhausts military radio operators while also making them obvious targets for the enemy. A new kind of antenna sown directly into clothing could reduce the burden and the danger for military radiomen, and eventually even provide enhanced connectivity for civilian wearable computers.
The antenna clothing uses light plastic film and metallic thread to enable radio communication up to four times farther than the military's existing antennas. That may not only lighten the load for U.S. soldiers, but could also free up the hands of astronauts, police officers or fire fighters, said Chi-Chih Chen, a research associate professor of electrical and computer engineering at Ohio State University.
Such a subtle device might even find its way into fashionable threads that integrate computers, or even one day transform a suit jacket or dress into a mobile Wi-Fi hotspot. Researchers have printing the antennas directly onto clothing, as well as embroidering them with metallic threads.
"Imagine a vest or shirt, or even a fancy ball gown made with this technology," said John Volakis, director of the ElectroScience Laboratory at Ohio State University. "The antennas would be inconspicuous, and even attractive. People would want to wear them."
The antenna clothing can send and receive signals in all directions without the need for an unwieldy external antenna. It can even send signals through walls and from inside a building.
"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," Volakis said.
But the Ohio State team first had to overcome problems posed by the human body's tendency to absorb radio signals and short circuit them. An improperly placed antenna might end up being blocked by the person's body if he or she moves against a wall.
The researchers embedded several antennas in different parts of a vest — chest, back, and both shoulders — so that the antennas can work together to transmit or receive signals no matter which way a person faces.
A computer control senses body movement and automatically switches between antennas to find the best signal performance. The computer device, no bigger than a credit card, is worn on the belt.
The prototype antenna technology may cost $200 per person, but the researchers expect that price tag to drop with mass production. They have partnered with an antenna design company, Applied EM of Hampton, VA, to commercialize the device.