Newswise — Electronic devices have been communicating over the air with ever-increasing fluency, but the growth will top out soon unless engineers can lay hands on more bandwidth.
The problem stems from the growing craze for high-definition video. Already video constitutes a huge chunk of the data flowing on the Internet, and its share is rising by the day. Vendors look forward to products that will beam high-definition video straight from your camcorder to your wide-screen television set; movie distributors plan to funnel full-length feature movies through wireless networks. To do these jobs in minutes rather than hours requires download speeds in the range of 5 gigabits per second and enough bandwidth to ensure that one download doesn't step on another one down the hall.
We can find the needed bandwidth way, way above the frequencies commonly used today, in the unlicensed territory around 60 GHz, according to an article in the February issue of IEEE Spectrum. Behzad Razavi, a professor of electrical engineering at the University of California, Los Angeles, notes that until now engineers had to use relatively inexpensive and power-hungry gallium-arsenide semiconductors to make chips that receive and transmit at those frequencies. Now, he argues, breakthroughs in the lab suggest that silicon chips are ready to take over the job, at a fraction of the cost.
One breakthrough has to do with the way antennas are built. The frequencies around 60 GHz tend to be absorbed by the air, and therefore they need to be focused carefully, using arrays of radio emitters and receivers known as adaptive antennas. Researchers have now demonstrated that they can fashion such an array on a single chip, greatly reducing the cost and the power requirements. Another advance has to do with the design of circuitry that chops the high frequencies down to size--so they can be processing at slower speeds--and then builds the result up again for transmission.
Because all of these developments can be done using the standard design for today's silicon chips, known as CMOS, the devices can, in principle, be manufactured very cheaply. When hundreds of GHz-capable chips can be salted through the electronic devices in a household or office, the network cable will at last go the way of the buggy whip.
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