Radar/Wireless Transmitter on a Chip 121
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."
Meaningless bullshit (Score:5, Funny)
How many Libraries of Congress is that?
Re:Meaningless bullshit (Score:1)
Re:Meaningless bullshit (Score:1)
Re:Meaningless bullshit (Score:5, Insightful)
Look how much trouble the teams are having putting together vehicles to race each other at 30 MPH on a closed course in the DARPA challenge. Many of them are using radar in conjunction with laser and visual systems in order to put together a world-view, and they are still having major problems running a course without other drivers.
Now add in all the erratic drivers, random animals, and kids running out into streets, and I don't think we are even close to having self-driving cars.
(two words) Collision Avoidance (Score:2)
This is just another component like those two innovations. It's not intended to drive around like George Jetson.
Radar on a car = Don't Be A Pedestrian! (Score:5, Interesting)
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
Re:Radar on a car = Don't Be A Pedestrian! (Score:3, Informative)
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 image.
At the bottom of the article he mentions that these things are used as a phased array. You don't have to mechanically scan the antenna. This allows you very rapid switching. As for rates, lets say that you want a 1k by 1k image at 10 Hz.
Re:Meaningless bullshit (Score:1)
Re:Meaningless bullshit (Score:1)
Re:Meaningless bullshit (Score:4, Informative)
radar clusters (Score:5, Funny)
Imagine a beowulf... oh nevermind. :)
Collision aviodance on cars at last (Score:5, Interesting)
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.
Re:Collision aviodance on cars at last (Score:5, Informative)
Check out the Cadillac XLR.
Re:Collision aviodance on cars at last (Score:1)
Re:Collision aviodance on cars at last (Score:1)
Re:Collision aviodance on cars at last (Score:2)
Only if the dumbass sitting on your tail also has radar braking...
Re:Collision aviodance on cars at last (Score:2)
My car had a bumper sticker: "Go ahead. Hit me. I need the money."
Re:Collision aviodance on cars at last (Score:2)
because braking is not always best (Score:4, Informative)
As someone who volunteers at his car club's high-speed driver education events and has attended one of the events as a student- um, no.
First, braking is NOT always the best choice. When you're doing 60 and a moose jumps out in front of you, you STEER, not BRAKE. Why? Because under about 200 feet, you're never going to stop in time but you probably can change lanes. Simple physics tell you why- it's a lot easier to accelerate a car enough to move 10 feet to the side than it is to bring the whole thing to a stop.
Second, when said moose jumps out in front of you, steering while braking is exactly what causes many accidents, because you unbalance the car, shift a huge amount of weight to one corner tire, which becomes drastically deformed under the weight and becomes nearly useless; meanwhile, there's next to no weight on any of the other tires, and they're useless too. Your tires have what is called a "friction circle"; draw an X-Y axis, now a circle centered. That describes how much acceleration your tire can accomplish in any one direction. Notice that there's less of any one particular axis when you're doing both? Your tires always stop better when you're not trying to steer, and vise-versa. Both controls should ALWAYS remain under control of the driver so the system doesn't try to do something while you're doing something else.
Third, proper driver education is a lot cheaper(just one $200-300 event, depending on the club, will teach you quite a bit about how to handle your car properly) in the long run.
Your friends who have been in accidents need to analyze WHY they got into the accidents they did. I'm guessing an automatic braking system would not have "fixed" any of this, but better attentiveness, good judgment, and proper knowledge of how to handle their car would have.
Re:because braking is not always best (Score:2)
Since then I don't so much as tap the breaks for anything weighing under 100 pounds. The lives of little crawly critters ar
Re:because braking is not always best (Score:1)
That sounds like good advice for race track conditions, but for some reason I think that on a two lane road, I would like to have the brakes on rather than swerving into oncoming traffic...
Re:because braking is not always best (Score:1)
As I said, I sometimes drive excessively fast, and occasionally I have gotten in wrec
24Ghz link/chip or core speed? (Score:5, Interesting)
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?
Frequency. (Score:3, Informative)
Re:Frequency. (Score:2)
I think that the article writers don't understand technology well enough, and the 24Ghz is the radio frequency only. I would bet that the processing center is much slower.
Re:24Ghz link/chip or core speed? (Score:5, Interesting)
Re:24Ghz link/chip or core speed? (Score:1, Insightful)
With the phases array, they should be able to measure the side of the object. Of course you are right that a cloud of pebbles could cause braking, but that might be ok.
Re:24Ghz link/chip or core speed? (Score:1)
If a car started braking over a cloud of pebbles, no one would use the features.
Current radar-based cruise-control technologies have to do things like measure the targets, determine the speed (and direction) of the targets, and determine if the target is legitimate. Then, the system must determine when/how to throttle the engine and when/how to apply the brakes.
Basically, the radar's the easy part.
And it's not something that costs millions of dollars, eithe
Re:24Ghz link/chip or core speed? (Score:4, Informative)
1 GHz is the maximum speed of the circuitry. (Score:3, Interesting)
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
please mod this down (Score:2)
- The system here can be easily accomplished with two or three chips today.
- The interesting thing here is a single CMOS chip implementation.
- The VCO is probably a DVCO (distributed voltage-controlled oscillator) [this aspect of the design might be considered a design major breakthrough].
- Things don't have to be "at least one wavelength".. In MMIC design you might care about 1/2 a wavelength... but regardless the antennas are off-chip anyways. And this
Re:please mod this down (Score:2)
brActually, they used a SiGe BiCMOS process from IBM
Re:please mod this down (Score:2)
They used a 16-phase 19GHz VCO made up of 8 tuned CNOS differential amplifiers
Re:1 GHz is the maximum speed of the circuitry. (Score:4, Informative)
Frequencies can theorectically be generated with any size circuitry. Im pretty sure this circuit does so using the so called Phase Locked Loop (PLL) circuit, possibly mixing 2 or more together to get the very very very very high frequency by addition. This circuit does not require wire coils (often of relatively large size) to resonate at these "really" high frequencies. There would need to be a filtering step (or two or three) and I can see how this circuit would be hard to miniturize, but I guess they have done it!
Typically for a radio signal to be radiated you need at least a half wavelength antenna but even this can be cheated at. In the microwave region where this device is working at, signals are best radiated using a "dish" type antenna. This chip no doubt does not come with this dish. It simply generates the rf at 24 GHz.
ZBeat
Re:1 GHz is the maximum speed of the circuitry. (Score:3, Informative)
The article specifically states that the chip implements a phased-array of antennas. And that those antennas are actually physically on the chip itself.
This is one reason why this solution will be cheap to implement - it does ALL the RF work for you, you simply connect "a computer" to the resultant datastream and interpret it how you like.
Re:1 GHz is the maximum speed of the circuitry. (Score:2)
What is the tuned circuit on the output? (Score:2)
Okay, but what is the tuned circuit on the output? There are no "LC tanks" at 24 GHz, right?
Radar chip is 24GHz (Score:5, Informative)
CMOS is getting fast enough (could be SiGe BiCMOS chip but probably CMOS) to allow for amplifiers and ADC (analog-to-digital) that work in the radar (~25GHz on up) range & also allows for million gate DSPs and digital logic on the same chip. The analog front-end is running around 24GHz which gives a 1/4 wavelength around 3mm (antennas are implemented as PCB traces off-chip). This is an analog GHz signal where the transistors are amplifying a tiny GHz signal using analog amplifiers. Digital clock speeds are completely different. Digital is like switching completely from off to on (ie. 0 to 5V -- in reality try 2V or 3.3V). This is like a uV signal being amplified to be later converted to a digital signal with a more reasonable bandwidth that a digital CPU could handle (like your overclocked Pentium).
The parallel analog antennas & blocks which allows for parallel ADC of 8 channels.. 8 parallel radar antennas. By using parallel processing you can use the information gained by the other channels to improve your ADC or have each channel only need to work at 1/8 of the total speed. Also, having 8 antennas allows phased arrays where you can control the beam and allows you to scan the beam or block out other signals (much like cell towers can focus in on one cell signal, and why your 802.11 router has two antennas). So, depending on how much bandwidth the ADCs need & how fast the DSP is running is really the 'digital' GHz part of the chip. So the digital processing is probably a more reasonable 100's of MHz (though hard to compare DSP speed to CPU speed). The processed digital waveform can be sent high-speed off chip, or to on-chip CPU to be used to disable your cruise-control and hit the brakes for you.
Why do you care? Well by using straight CMOS the radar system can be made on one chip and not need 'exotic' GaAs/SiGe/InP (BJTs of traditional radar systems) and when the automotive chips get down to sub-$5 they will show up in every car. Also doing it this way, much smaller power is involved and you don't need circuits that look like your microwave oven waveguides.
Re:Radar chip is 24GHz (Score:2)
They used an IBM SiGe proces according to my ISSCC digest
Re:24Ghz link/chip or core speed? (Score:2, Insightful)
Unless someone's at least ten years ahead in tech out there?
Re:24Ghz link/chip or core speed? (Score:2)
They use a Sige process from IBM, from which it is possiible to make a 24 GHz mixer and divder.
Re:24Ghz link/chip or core speed? (Score:1)
Re:24Ghz link/chip or core speed? (Score:2)
Your CPU has paths more than one gate long that have to switch each cycle. Even if you DID design a processor with 1 gate per pipeline stage, you'd still need more than 41ps just for the clock-to-q (time it takes the data to come out of a flip flop) and setup of the next flop (time before the clock arrives that the data needs to be valid).
A couple of questions come to mind... (Score:5, Interesting)
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
Yes Indeed.. Read the article. (Score:1, Informative)
ONE Of these chips can. It's a phased array (aka synthetic aperature) radar on a single chip.
Probably. Researchers were doing this with hydrophones picking up background noise 5 years ago (sorry, I don't have a link, I read it in Scientific American)
Re:A couple of questions come to mind... (Score:1)
Low cost RFID scanners (Score:5, Interesting)
Re:Low cost RFID scanners (Score:1)
Re:Low cost RFID scanners (Score:3, Insightful)
I don't see what having a strong RF field generator on chip does? See, how they work is low/no power needed on-chip which is then excited by RF field and the chip replies with a signal which identifies it. What good does an on-chip "interrogator" do? And how exactly does help this adoption along?
Sounds like fun... (Score:5, Interesting)
... 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.
Re:Sounds like fun... (Score:1, Informative)
Re:Sounds like fun... (Score:1, Insightful)
That's because you're probably not staying to the right. Quit shitting your pants because of what the other drivers think. If you're on the right lane, they have plenty of other lanes to drive like a dumbass.
Complaint about traffic ticket (Score:2)
I am about to send a letter to the court about a ticket I received 2 weeks ago, and have already paid.
I believe that the primary purpose of our traffic laws is to make every driver into a criminal. The officer wrote me a "Disregarding the Signs" ticket which costs money, but does not affect my license. If he felt I was a dangerous driver, he should have written the ticket to reduce my ability to drive, or to force me to take driving classes. His pe
Re:Sounds like fun... (Score:3, Insightful)
Good point, but over here you get screwed over if you even go 4 kmh ( roughly 2,5 mph ) over the limit. They don't care if you're overtaking at the moment or not. Besides, the police are supposed to keep speeding under control where relevant, not where it is most profitable.
It's quite a riot over here in the NL, where our goverment and police ( on all levels ) are practically conspiring against people with cars. Instead of maintaining control at essential points where people might actually be in danger fr
Re:Sounds like fun... (Score:3, Funny)
Which reminds me of little story:
A man was driving pretty fast over a bridge when he was stopped by a cop.
What's the hurry?
I'm late for work.
What kind of work do you do?
I'm a doctor. I stretch assholes.
Say what??
Yes, I stretch assholes out to about 6 feet.
What do you do with a 6 foot asshole?
Give him a radar gun and put him on the end of a bridge.
anti-Fuzz Buster (Score:2)
Application Errors in the Article (Score:5, Informative)
Not really. The radar might reflect off the cat or your leg, but would pass right through wooden furniture and walls. A radar-equipped vacuum cleaner would still bump into stuff.
* A chip the size of a thumbnail could be placed on the roof of your house, replacing the bulky satellite dish or the cable connections for your DSL. Your picture could be sharper, and your downloads lightning fast.
Wrong on size. Satellite dishes are big to both help collect enough RF energy to get a clean signal and to pinpoint on a single satellite. Without the needed collecting area and beam-forming span of the antenna, the signal would be weak and overlaid with signals from other satellites in orbit.
Re:Application Errors in the Article (Score:5, Informative)
Hajimiri's chip runs at 24 GHz (24 billion cycles in one second), an extremely high speed, which makes it possible to transfer data wirelessly at speeds available only to the backbone of the Internet (the main network of connections that carry most of the traffic on the Internet
24GHz is just the operating frequency not the bandwidth. You do have alot of free bandwidth, free is in not sold already, but your still not going to get close to OC-192 speeds. The most rf bandwidth your going to get is maybe 500 Mhz and with 802.11g tech your getting around 20mbit of useable bandwidth out of 6Mhz. So (500/6)*20 = 1666, thats 1.67 gbit, not bad, but nowhere close to backbone speeds of 12gbit.
This technology could replace the dish, but it won't be the size of your thumbnail. A phased array could be used to obtain a fare amount of gain with a 12x12" panel.
Reaching for my tin foil hat... (Score:2)
It's not that I'm concerned so much about one or two of these things. It's the c
Frequency allocation for 24 GHz? (Score:5, Informative)
According to this press release [bmwnation.com] it's not licensed in parts of Europe.
And in the US, there is only a temporary license.
I haven't found an unbiased summary yet - the referenced press release is from a working group of companies in the automotive industry.
This summary [etsi.org] says that the frequence is reserved for radio astronomy and similar users.
Re:Frequency allocation for 24 GHz? (Score:5, Informative)
Re:Frequency allocation for 24 GHz? (Score:1)
Re:Frequency allocation for 24 GHz? (Score:2)
Also, I wouldn't be surprised if the FCC allows use of that band by unliscensed Part 15 users on a non-interference basis (ex: The 2.4GHz band your Wi-Fi network runs on is also allocated to the Amateur service, but you can use it anyway as long as you don't cause me interference). If a spread spectrum mode or similar
Re:Frequency allocation for 24 GHz? (Score:3, Interesting)
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 [astron.nl].
Radar Detectors will become useless (Score:5, Funny)
Maybe they can be replaced with very sensitive tri-sensor devices that test for a specific combination of: doughnuts, coffee, and bacon.
Re:Radar Detectors will become useless (Score:5, Informative)
X Band operates on ~10.5Ghz
K Band operates on ~22.4Ghz
Ka Band operates on ~34-35Ghz
(source: http://www.snooper-uk.com/radar_laser_speedtrap_b
The article states the frequency being used of is 24Ghz, so the only possibly problem might be with K band detectors.
I dont think they would put both in the same band anyway.. wouldn't that interfere with the radar guns themselves?
Re:Radar Detectors will become useless (Score:2)
I'm pretty sure it was a cadillac of some sort with a old couple in it, but i've never seen that problem at any other time.
Of course driving past supermarkets with automatic doors causes problems..
Re:Radar Detectors will become useless (Score:2)
The policeman's triathalon...tri altholan...triatholan...oh, whatever.
Resolution (Score:5, Interesting)
That would be really cool for a small robot if it could.
Re:Resolution (Score:4, Informative)
Re:Resolution (Score:2, Interesting)
For the first you are just measuring time of flight and can look at the phase of the return signal to really pin things down. For the second, if it's too small, the radar doesn't even bounce off.
Re:Resolution (Score:1)
Hype (Score:5, Interesting)
And conventional radars do not cost "millions of dollars".
Re:Hype (Score:2, Informative)
Funny. The article I read says the antennas are on the PCB. What's new is they used Si, instead of more exotic materials.
nothing new (Score:1, Interesting)
Traffic monitors (Score:3, Insightful)
In your car have a GPS map that has wireless capability to these units. You can get a real-time traffic density map of the city and decide if you want to take the freeway home or take another route...
Seems like a pretty easy app to set up also.
Re:Traffic monitors (Score:3, Interesting)
Robotics (Score:2, Informative)
This is interesting (Score:2)
What makes you think they are hi-po? (Score:2, Insightful)
And the beam-focusing aspect means that 100 mW can go a long way.
I was thinking that the communications aspect may be the big payoff, think what this would do
Too late for Intel and AMD... (Score:2)
This would be the perfect reason to boost clockspeed - if this chip is cheap, fast, and has low power consumption, it would be perfect for wireless networks. In fact, if this chip is as commodized as the article tends to imply, then depending on range it could make ad-hoc networks simple and easy.
But since it runs at 24 Ghz, even one stream would be too much for a standard server or one
Radar on a Chip (Score:1)
Re:Radar on a Chip (Score:1)
Basically, it was a CMOS "Linear Feedback Shift Register", aka "PseudRandom Sequence Generator" (PSRG) which generated a predictable stream of 1 and 0. The output signal went to both a "D" type flip-flop and the class-C buffer amp which fed the transmit antenna. The idea was not to transmit the levels of the PRSG, but just the edges. Those edges are sharp and transmit well... ( eh, ANY digital edges are sharp and transmit well, and we jump through all sorts of hoops
range anyone? (Score:2, Interesting)
Harmonics (Score:2)
Re:Harmonics (Score:3, Informative)
Transmit; listen; figure out the difference between what you heard and what you should have heard if it went on indefinitely (ie no relfection). Repeat, very quickly.
The listen
Re:Harmonics (Score:2)
When I started DSP progra
Re:Harmonics (Score:2)
Semantics indeed. Of course I do know you can synthesize a subharmonic by studying the upper harmonics (lots of relatively inexpensive products do it now and have for a while); it certainly seems to be valuable as an error-correction mechanism.
I see now you were referring to a system that involves receivers that listen at higher than the fundamental (many times higher, to work right) and then reconstruct what must have been below. For some reason I though your original post wa
Re:Harmonics (Score:2)
Smart Wheels (Score:1)
Body Aura-mour (Score:1, Insightful)
I think I coined this first: Body Aura-Mour...
Imagine this being used on soldiers' ensembles... you could wear a weapons system that tags friends' IFF transponders to reduce fratricided (accidental or intentional, to prevend fragging the 2/LT);
It could be used to locate and link up with allies, or to sneak up on unsuspecting targets in almost any kind of weather.
Moreover, it could help police and firefighters. Ever more frightening, school kids could me made to rent them and affix them to
No more speed traps... (Score:2, Interesting)
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
Re:No more speed ... (handing out reality checks) (Score:2)
RADAR doesn't track "the speed" of an object, but actually only measures its distance (and we get the {relative} speed by calculating change in distance over time).
RADAR is probably going to have a hard time giving you the speed of what amounts to an infinitely large something which is a constant distance from you.
And while we're at it, because it's only tracking distance, and you're looking "at the ground,
It's not the proceessing speed that matters. (Score:2)
24GHz is an FCC assigned band for automoive radar. The processing speed isn't the issue since the radar signal is mixed down to extract the basesband info, which is processed at a much slower rate. 24 GHz is significant since phased array antennas at this frequency are getting sm
operation clarification (Score:2)
24GHz is the carrier frequency of the radar. The amount of information in a signal is related to the bandwidth of the signal, as well as linearity and noise. This design was done in SIGe BiCMOS, which is more than capable of designing a wireless tranceiver at 24Ghz RF frequency. The phased-array signals are mi
I am not smart enough (Score:2)
I'm