Slashdot Mirror
Record High Frequency Achieved
eldavojohn writes "Researchers at UCLA Henry Samueli School of Engineering and Applied Science managed to push our control of frequencies to another level when they hit a submillimeter 324 gigahertz frequency. As any signal geek out there might tell you, this is a non-trivial task. 'With traditional 90-nanometer CMOS circuit approaches, it is virtually impossible to generate usable submillimeter signals with a frequency higher than about 190 GHz. That's because conventional oscillator circuits are nonlinear systems in which increases in frequency are accompanied by a corresponding loss in gain or efficiency and an increase in noise, making them unsuitable for practical applications.' The article also talks about the surprising applications this new technology may evolve into."
The article also talks about the surprising applications this new technology may evolve into
Like making your dog's head explode.
Think of the bees :p
Precision phase coherent control of lasers has become possible in the last ten years- Laser beams at frequencies exceeding 1 PHz (10^15 Hz) have been precisely controlled, phase locked, and tuned to have frequencies that are *exact multiples* of our best microwave frequency standards (e.g, cesium). It works the other way too-- our most precise microwave-frequency signals come from divided-down optical frequency references now! See also: 2005 nobel in physics.
More than 15 years ago, quite a few of the students at the physics lab I was teaching had their oscillating circuits reach 483 terahertz and more pretty easily. For a short amount of time that is.
This sounds a lot like a phased-lock loop. And yes, from the article, it appears as though this does have pretty good scalability. TFA said 600 GHz is achievable. 324 GHz a nice because fog is transparent at that frequency.
They found frequencies... they didn't even know existed?!
+1 funny
-8 bad movie
-9000 overrated
-- 'The' Lord and Master Bitman On High, Master Of All
"TFA said 600 GHz is achievable. 324 GHz a nice because fog is transparent at that frequency."
So in twenty years time cars will have an anti-fog display on the windscreen (which will have the ability to switch between transparent and display mode), which will make travelling through fog much safer at high speeds (let's just accept that cars will not have an auto-drive mode by then, eh?).
On the downside, many crashes will occur because pedestrians on the sidewalk will appear to be naked! Perverts will be making the school run even worse as they hang around outside schools. And we'll all accept it as the price to pay for safety and anti-terrorism requirements.
They got a Vista score of 5, so obviously it's running at 324GHz
[an error occurred while processing this directive]
This technology is another step along to road to widespread technology exploiting Terahertz radiation, which is the region of the EM-spectrum between IR and microwaves. Near the end of the article, they mention the possibility of creating imaging systems that can, for example, see through clothes. These applications of so-called T-rays have in fact already been demonstrated. For example, the image in this article shows a man concealing a knife, which is easily visible in the T-ray image. (See also some other pictures here.) T-rays reflect strongly off of metals but can penetrate to varying extents through things like clothing and tissue. The military and security applications are obvious. However it would also bring up new kinds of medical imaging, and has been investigated for quality control, too (for example, scanning the inside of foods in assembly lines, etc.). In the previous link I put, there is an example of scanning through a Hershey bar, where you can see the positions of the nuts.
Suffice it to say this is an area of active research that may have many, many applications.
People across the nation began shitting themselves for no apparent reason. Victims recall feeling an unusual vibration in their bowels before immediately discharging feces. Some believe an evil genius may have finally discovered the "brown note". For Action 11 news I'm....oh god.....>PPHHBBBBHHTTHHHHH!!!!!
Take that Mythbusters!!!
This post was clearly planted by the U.S. government.
"When the atomic bomb goes off there's devastation...but when the atomic bong goes off there's celebraaaaation!"
What they did sounds like an extension of the technique used in push-push oscillators to "double" the oscillation frequency.
The basic principle behind a push-push oscillator is that two out-of-phase signals of fundamental frequency f_o are combined such that the fundamental signal and the odd harmonics cancel, while the second harmonic at 2*f_o add constructively. In the case of a push-push oscillator, you only need two signals 180 degrees out of phase. This could be generated with a differential VCO.
Using a push-push oscillator is a well known technique for increasing the frequency of oscillation of a VCO beyond the fMAX of a transistors at a given process node.
The only disadvantage with push-push oscillators is that you end up losing a lot of power as the second harmonics's power will always be much smaller than the power in the fundamental frequency of the VCO.
I can create an even higher frequency for a fraction of the cost.
(Turns on flashlight)
I can even send information.
(Blinks flashlight)
I admit the data capactity needs work, though.
Aye, the heterodyne radio receiver. Yeah, I could see them using a mixer! That doesn't mesh with what's described, but, then, (unless I am missing something), what's described doesn't make a ton of sense:
How can any linear system create an output frequency unequal to one of the input frequencies? I could see rectification as providing a frequency doubling -- but that's old, old news, generates horrid output, and is probably not what's referenced here.From TFA:
So maybe the article gets it wrong, and you're right?
If somebody else could shed some light on this, that'd be cool.