Radar/Wireless Transmitter on a Chip

dganapa writes "Researchers at the California Institute of Technology, headed by Dr. Ali Hajimiri, have developed a low-cost radar system on a silicon chip. The entire system has been designed from the ground up on silicon, thus leading to reduced cost as well as robustness in response to design variations and changes in environment. The chip runs at a staggering speed of24 GHz (enabling it to transfer data as fast as the main network of the Internet) and can soon lift wireless, high-frequency communication to a whole new level. The radar as such is not as powerful as a conventional radar but because of its cost-effectiveness, a number of them can be coupled together to perform really well. A related NY Times article is here. A recent article from Slashdot shows that radar technology is increasingly being implemented in the automobile industry. This current chip is sure to be much more successful than its predecessors as far as the automobile industry is concerned, but whether or not its processing speed will become important in the computer industry remains to be seen."

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for the lazy

[frazzydee]

for those too lazy to register an account- here's the new york times article:
RADAR technology was once synonymous with the big and the bulky - for instance, the heavy, rotating antennas at the airport, scanning skies and runways. But lately radar, like so many other technologies, has been slimming down. Now a team of electrical engineers at the California Institute of Technology has shrunk the functions of a radar system into one tiny, intricately designed silicon chip and eight minuscule antennas. The basic building blocks of the radar system are all fully integrated on the chip, including power generation, signal processing, and dozens of other functions. The intricate parallel circuitry is designed so that the eight antennas can work together to focus and steer a beam of microwaves. Although the circuit design is highly complex, the silicon chip can be made in bulk using inexpensive lithographic methods, said Ali Hajimiri, an associate professor of electrical engineering who leads the group on high-speed integrated circuits that created the chip. "It should cost no more than a few dollars," he said. The high-frequency beams that the system generates and receives may one day handle many functions, including the usual radar jobs of ranging and location. In cars, for example, the chip might be used to detect other vehicles looming in the fog. The chip may also be used for wireless communications, since it has a broad bandwidth or range of frequencies at which it communicates. And it produces a bit stream at roughly the rate of fiber optics, more than enough for quick downloads of movies and other digital data. "D.S.L. can go to several hundred kilobits, and fiber can go to several gigabits per second," Dr. Hajimiri said. The radar chip can achieve bit rates up to a gigabit per second, partly because of the concentrated nature of the beam, he said. "The beam created by the chip is highly focused," he said. The chip could combine the functions of sensing and communication, say, for a group of army tanks that needs to stay in touch in the field. "Using these extremely high frequencies, you can first capture location, sending out pulses and scanning the area like a bat," said Volkan Ozguz, chief scientist at Irvine Sensors in Costa Mesa, Calif. Irvine Sensors makes miniature electronic systems, including sensors. "Then, using the same chipset, you can start communicating at high frequency," exchanging information without switching to different equipment, he said. The new radar chips do not create pulses as powerful as those now used in aviation systems, but they could be used in arrays to multiply their power, Dr. Hajimiri said. The eight antennas on the new chip are not the sort that protrude from old-fashioned rotating radar shells. Instead, the antennas - actually traces of metal on a PC board - do not move at all: their bearings are adjusted not mechanically but electrically by circuits that imitate the behavior of rotating antennas, focusing and steering the beam of radio signals in the right direction. Usually the radiated signals arrive at the separate antennas at different times. But electronic devices called phase shifters compensate for these delays, in effect combining and enhancing the collective power of the signal for a desired direction, and rejecting emissions from other directions. "It's neat because you can get the eight antennas to work together so that you can transmit in a narrow beam," said David B. Rutledge, a professor of electrical engineering at Caltech and a colleague of Dr. Hajimiri. "Then you transmit with eight times as much power." The phased array antennas can be made insensitive to unwanted signals, limiting interference. "In cellphones, when you add people, there's interference," he said. "But these circuits can figure out how to reduce power from a direction they don't want." Dr. Hajimiri used a comparison between a light bulb and a laser pointer to explain how the chip could make the best use of its power. Light bulbs illuminate the whole space, he said, but a laser c