Slashdot Mirror
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."
(yes - of course we can disable it if we want to)
but wouldn't it be great to have the brakes applied if you lose attention for that one split second. Everyone I've known who has been in a car accident, (luckily they were minor) has said just that.
Unless you are James Bond, or just want to do some fancy driving a radar controlled braking system would be great.
You can't expect to wield supreme executive power, just because some watery tart threw a sword at you
Why can't I get my liquid nitrogen cooled 24 Ghz ahtlon64 then? I thought we weren't capable of making gates that would switch that fast?
Can someone clear up my confusion?
TODO: 753) write sig.
... and no I haven't read the article yet.
can an array of these be used to emulate a synthetic apreture radar, meaning that a flat panel gives you a 120 to 180 degree field of view from that panel?
Can the processing power of the chips be used to provide an improved image of what is reflecting in the spectrum the radar is working in? With a two dimensional array of 5 by 5 chips, distributed over a 1 foot by 1 foot surface, you could have a 3 dimensional "image" with a resolution similar to a human's 2 eyes. If the chips themselves can be programmed to do the interpolation, you could use a seprate computer to provide a opengl real time image of the world.
Perhaps I should read the article...
-Rusty
You never know...
This same technology could be used for low-cost RFID scanners. If manufacturers can bundle an entire RFID interrogator on a silicon chip, it would reduce scanner costs and accelerate RFID adoption. The low power of this silicon-based GHz RF would be acceptable in many RFID scanning applications.
Two wrongs don't make a right, but three lefts do.
... having radar in your car. Just don't be surprised one the police finds a way to screw you over for a few more bucks by using passive radar to determine your speed.
Hate me!
If my early morning math is right the wave length of 24Ghz is about half an inch. Does that mean that the chip could distinguish distances as small as half an inch?
That would be really cool for a small robot if it could.
Yes. See FCC ruling. One of such radars
I believe the issue of opening up this frequency for automotive use is currently being debated in Europe, too.
There are protected bands around 23.7 GHz for ammonia spectral lines.See this list.
Just guessing: The radar signal is generated by a microwave oscillator formed by some kind of folded structure on the silicon. The structure must be folded because it must be at least one wavelength of the generated frequency. The wavelength of a 24 GigaHertz signal is:
(300,000,000 meters/second [the speed of light, approx.]) / (24,000,000,000 cycles/second [24 GHz]) = 0.0125 meters, or a wavelength of 1.25 centimeters.
In photos, the radar chips are shown to be less than 1.25 centimeters in width and length. That makes me guess that there is some folded resonant structure.
Does anyone know if that assumption is correct? Is it possible to generate a signal from a structure smaller than one wavelength?
One of the articles says that the maximum transmission speed is 1 GHz, so that is the maximum speed of any digital or analog circuitry. The governmentally designated band is 22 to 29 GigaHertz, so the theoretical maximum speed of data transmission is 7 Gigahertz, the width of the frequency band.
This is a major breakthrough. A large number of these chips can be combined with digital signal processing to make a radar that has an effective antenna size much larger than each chip. Large effective antenna sizes are also great for reliable directed data transmission.
The chip is neat, but the article is very heavy on the hype. The only new thing here is putting everything including the antenna on one chip.
And conventional radars do not cost "millions of dollars".
Warning: this article may contain humor, sarcasm, parody, and perhaps even irony. Read at your own risk.
It really isn't that new or novel.. Just a PR Prof trying to toot his horn.
It could be a component, but only one piece. The really tough part if creating the software that intelligently drives. There are so many oddball cases you have to deal with in driving that it will be a very long time before this is possible.
I don't think the goal is that loft at this point - we're talking about an aid for the (human) driver to see through fog.
Quoted from the first line of the article:
Imagine driving down a twisty mountain road on a dark foggy night. Visibility is near-zero, yet you still can see clearly. Not through your windshield, but via an image on a screen in front of you.
This would be nearly impossible to implement by radar alone, but this is a step towards it.
The problem, of course, is clutter. Fog, snow and rain all obscure your view through radar because of clutter and attenuation. Even with a very intelligent algorithm combining the skills of hundreds of experienced mariners, finding the sweet spot on the clutter and gain controls is difficult.
Another issue is "obstructions" which won't cause an echo at all - like the very big fall waiting for you on the other side of the missing guardrail.
Let's consider a worst-case scenario. It's raining. The gain and clutter are configured to give you a clear view of cars in front of you, guardrails, concrete obstructions, rocks, etc despite the driving rain.
A few minutes ago, a truck drove down the road and a forklift pallet of toilet paper fell off the truck. Do you think your radar is going to show you its echo? I think its relatively weak echo will be filtered out as clutter...
How about something more substantial, a big square rooftop HVAC unit sitting on the road, one of its four corners pointed directly at you? Even under the best possible circumstances, it's going to be very hard to get an echo off that, since there isn't a surface normal to the RF energy leaving your car...
Or a kid, wandering around the road. Daddy had an accident because he trusted too much in his automotive radar system, and has been hurt. The clutter on your own radar system is set high enough to obsure the echoes from the water droplets of the driving rainstorm. Now, what kind of echo are we going to get off a human being, considering that we're mostly water?
I've seen people on radar systems. You really don't see much, and I don't care whether it's X-band or S-band, a crappy little Furuno bought at the yacht club or a $200,000 interswitched Lloyds type-approved Racal-Decca ARPA radar used on an aircraft carrier. You're still not gonna see much of a target.
While I was designing radar video systems for Litton (before the tech collapse), we had constant reports that bridge crews were using the radar for navigation, rather than properly sighting, having crew on watch, and bringing the ship to a slow speed with due consideration of conditions.
The ship's captain probably has 20 years experience at sea, and is now in charge of a multi-million dollar vehicle with many lives on board. These are responsible, intelligent and experienced people. And they often take their radar's accuracy for granted.
How, then, are we going to get Joe Sixpack who currently thinks nothing of driving around in his SUV, cellphone planted to his ear, to understand that the radar image presented to him is NOT infallible? That it is, despite its ability to "see" through fog, snow and rain, actually less accurate than the human eye?
Hell, how are we even going to teach him to read the display? With several years of experience reading PPI radar displays, there's no way in hell that I would ever try to use it (or just a quadrant sweep) to drive a car. It's just not as intuitive as it would seem, and I can't even begin to imagine what sort of work would be required to try to create something like a TV picture of the road ahead.
First off, to scan the image, the transceiver's antenna would have to be scanned - physically moved around - at the same speed as the desired refresh rate of the
Fire and Meat. Yummy.
Imagine placing these chips on top of light poles every 1/2 mile on big city highways. Now enable them to start photographing drivers and license plates whenever excess speeds are detected...
Caveat Emptor is not a business model.
I know everyone is excited about the chip that uses almost no power to act as a radar. However, unless they re-write a few laws of physics, I thought the range of a radio signal was dependent upon its power with a few other environmental factors thrown in. Did I miss something, or has no one stated the range of this device yet?
Well, in about 15 years at least...
...At least 15 years in the USA to get all the juristictions on the same page. The way most people drive, this is like money in any Goverments bank that posts a speed limit.
To get a licenced vehicle it will have to have a similar chip in it, pointing at the ground below the car 2 feet from the cars edge. The car will report the speed to you and the cops. No high speed chases, just a ticket or summons in your mail box, maybe it will even triggar an auto-funds-debit (no pun intended.) Forget self driving daydreams, the reason we like to drive is autonomy (again no pun.) Even futuristicly, self driving is a luxury add-on, that this chip might only make slightly less cost prohibitive for general production. As part of an Auto's BlackBox/Lojack system this would be a very, very ecconomical inclusion.
Hmmm, I wonder how many snapshots a digital camera (or bank of cameras) would take in focus with this chip by its side? Entry ways, crowd scaning; can this chip be used in high speed facial reccognition systems?