Tuesday, Feb. 17, 2009 | A University of California, San Diego researcher last week unveiled an invention that he hopes will bring the world another step closer to a level of wireless communication that is still more prevalent in fiction than real life.
James Buckwalter, an assistant professor of electrical and computer engineering at UCSD’s Jacobs School of Engineering, has developed a new signal amplifier for the silicon chips imbedded in cell phones and other devices that will allow them to handle 10 to 100 times the bandwidth and signals on much higher frequencies.
The invention means that dramatically higher quality video on demand, video conferencing and other data-intensive wireless applications might be commercially available much sooner than previously thought. So instead of a grainy picture, the screen freezing up and delayed audio, “instantaneous remote visual interactions (teleconferencing) will be movie quality,” Buckwalter said.
“It is a big step,” said Larry Larson, chairman of the Jacobs School’s electrical and computer engineering department. “I would have to say that in the history of this field there have been four or five innovations, and this may be the sixth.”
Buckwalter presented the invention, which he named the “cascaded constructive wave amplifier,” Wednesday at the International Solid-State Circuits Conference in San Francisco, the largest and most prestigious annual event for chipmakers like Qualcomm and Intel. “It took awhile to believe it,” Buckwalter said of his breakthrough. “There is a rush of emotion — that this is something no one has done — and it works.”
The underlying conundrum that spurred Buckwalter’s invention is that all wireless networks — from cell phone networks to the network you log your computer onto at the coffee shop — were designed to handle small bandwidth data that can be transmitted across the electromagnetic spectrum at a low, so-called radio frequency level.
But today’s cell phones, computers and televisions are transmitting video and other data that is overwhelming these low frequencies now being used on the spectrum. So the networks — such as Verizon’s or AT&T’s — will have to move to a higher, or millimeter wave, frequency on the spectrum where data transfer rates are many times faster.
“Think (in terms of bandwidth) of radio frequencies being Connecticut, and microwave frequencies being Montana — we need to be in Montana,” Buckwalter said.
The problem is silicon chips in cell phone handsets and laptops have a difficult time generating any power at very high frequencies. So they need to be beefed up with an amplifier — like a guitar needs to be beefed up if it is going to be played in a large arena. But developing a so-called millimeter wave amplifier that is both reliable and cost-effective has, until now, vexed researchers. Many of the existing millimeter wave amplifiers require exotic and expensive semiconductor materials.
Buckwalter’s amplifier can be put on a silicon chip, and amplify the wave as it travels through the chip without limiting bandwidth. The goal, he said, is to manipulate the electromagnetic wave so it behaves like a wave in the ocean, gradually growing larger as it travels across the surface.
The device is still at least five to 10 years away from being a commercial application, Buckwalter said. And like any invention in a fast-changing industry, it could be rendered obsolete before it sees the light of day commercially. “I will have to wait and see if time respects this idea,” Buckwalter said. “It’s about seeing where your idea is after many years.”
Buckwalter said the work he and other researchers are doing to make wireless networks more robust is crucial as remote visual interactions become more prevalent and key to doing business on a global scale.
“In my vision people will be very comfortable collaborating, solving problems not just face-to-face, but using networking tools,” he said. “But unless you can really interact with someone’s facial gestures, it is hard to have a comfortable remote interaction.”
Larson reiterated Buckwalter’s caution about the years between a presentation at a conference and a commercial product, but said that the invention generated “quite a stir” at the San Francisco conference.
He said it was the latest in a string of breakthroughs by the school of engineering. Stojan Radic recently set the world record for sending optical signals down a fiber optic cable. And within the last year and a half, Gabriel Rebeiz developed a radar technology that will allow low-cost radar systems such as collision warning systems in cars.
“We are reaping the benefits of an investment that was made many years ago by the state of California in Calit2 (California in Institute for Telecommunications and Information Technology),” he said.
This article relates to: Science