Month: December 2012

A new silicon microchip can do what no other silicon microchip could before, generating and transmitting radio waves in the terahertz range. The tiny chip operates at 300 times the speed of the CMOS chip in your smartphone, and could someday be used to peer through walls, inside containers and into the food supply.

It can see a knife hidden inside a teddy bear, like the image above. It can even determine the fat content of a piece of chicken, apparently.

Terahertz scanners have long been touted as the future of security–electromagnetic waves in that frequency range can penetrate where other forms of radiation cannot, but they don’t produce the damaging ionizing radiation of X-rays. T-rays can sense every molecule, so they could theoretically detect illicit drugs or explosives, or even hunt for cancer cells. They can see through walls and inside objects, so they would be useful security screeners. The problem has been that the scanners are huge, requiring lasers and many lenses to focus light, not to mention cooling equipment to keep everything at operating temperatures.

For that reason, electrical engineers have been trying to build terahertz scanners using common and cheap manufacturing processes, especially the complementary metal-oxide semiconductors that power most consumer devices. Earlier this year, researchers at the University of Texas at Dallas figured out how to build a special type of high-speed diode in CMOS, producing T-rays on a small scale. Now some researchers at Caltech have done one better, producing the world’s first integrated T-ray arrays.

The mere fact that it operates at terahertz frequencies is a breakthrough. No standard transistors can amplify a radio signal in that range. Silicon chips aren’t designed to operate in it. To get around those limitations, electrical engineering professor Ali Hajimiri and postdoc Kaushik Sengupta combined several transistors on one array, all operating in unison. When operating at the right frequencies, the transistors’ collective power can be combined, boosting the signal’s strength. In a Caltech news release, Hajimiri compared it to an army of ants hefting the same load as one elephant. “Nowadays we can make a very large number of transistors that individually are not very powerful, but when combined and working in unison, can do a lot more,” he said.

What’s more, they figured out how to get the entire chip to operate as an antenna, incorporating several pieces of metal instead of a single wire. (A wire wouldn’t work at terahertz frequencies.) The result is a chip-scale scanner that can produce and distribute T-rays. IBM helped produce the chip, according to Caltech. Hajimiri and Sengupta describe their new chip in the December issue of IEEE Journal of Solid-State Circuits.

[Caltech]

No related posts.

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Linus Torvalds has officially announced that version 3.7 of the Linux kernel has gone stable, and that means good news for developers who work with ARM-based CPUs: among its other changes, Linux 3.7 is the first Linux kernel to include generic support for multiple ARM CPU architectures, reducing the amount of effort required to get Linux-based operating systems running on phones, tablets, and ARM-licensed developer boards like the Raspberry Pi.

At present, every time a developer wants to port a Linux system to an ARM system-on-a-chip, they have to build a new kernel to support that processor’s particular architecture. Additionally, differences between ARM chips from different companies means that porting that same Linux-based OS to another ARM processor—for example, taking code running on a Samsung SoC and making it run on a Qualcomm SoC—requires another kernel. The work required to maintain these separate kernels for each ARM SoC is a major roadblock for the architecture compared to x86 chips traditionally used in desktops and laptops, and overcoming this issue will be a major step forward for Linux and its forks, including Android.

This work mirrors the effort that Microsoft also exerted for Windows RT, which likewise supports many different ARM architectures with the same kernel.

Sure, you can run Speedtest.net or max out your BitTorrent download, but as we found out last month, it’s hard to get a good gauge of how fast and consistent an ISP is using real-world, high-bandwidth applications.

But Netflix, as one of those high-bandwidth services, is taking matters into its own hands and has published its first monthly ranking of major ISPs, “based upon their actual performance across all Netflix streams.”

On Tuesday, Netflix wrote that Google Fiber, which is limited to a few hundred users in Kansas City (Kansas), “is now the most consistently fast ISP in America.”

Enlarge / Administration panel for Dexter, a malicious application that steals credit card data from point-of-sale systems. The malware was recently found on hundreds of computers around the world.

Seculert

A researcher has uncovered new malware that steals payment card data from point-of-sale terminals used by stores, hotels, and other businesses.

Dexter, as the malware is called, has infected hundreds of point-of-sale computers at big-name retailers, hotels, restaurants, and other businesses, according to a report issued by Aviv Raff, chief technology officer of Israel-based security firm Seculert. Businesses infected in the past three months are located in 40 different countries, with 30 percent of those compromised located in the US, 19 percent in the UK, and nine percent in Canada. Malware that infects point-of-sale terminals can be one of the most efficient ways to carry out payment card fraud because it targets machines with access to large amounts of the required data.

“Instead of going through the trouble of infecting tens of thousands of PCs or physically installing a skimmer, an attacker can achieve the same results by targeting just a few POS systems with specially crafted malware,” Raff wrote. “Dexter is one example of such malware.”