GREAT-Terry, this is Sam Weinstein of Analog Devices, one of the authors of the article. You are correct that the user can achieve a sample rate of ~13MHz per channel with the AD8283 (or higher if less than 6 channels are used). Radar systems work by sending out a frequency sweep and “listening” for the echo. Minimum ADC sample rate is dictated by the baseband signal frequency content, which is the echo signal mixed with the transmit signal. Received baseband signal bandwidth depends on sweep rate, sweep frequency content, and maximum target distance (range). For example, a sweep rate of 50us, sweep frequency content of 100MHz, and a range of 150m corresponds to a 2MHz BW. You want the sample rate per channel to be about 3x or 4x the frequency of this, or about 6 to 8 Msps. Regarding your other question, SNR of the AD8283 is one of many factors that affect the overall system accuracy. SNR, among many other specifications, were closely worked out with our customers who are building automotive radar systems.
Can anyone tell why 12 bit 80Msps ADC with mux (so ~13Msps per channel - assuming no latency) is a good solution to the radar? I mean what factor dictates the sampling rate of the ADC? Is 67dB SNR good enough? Again, what is the baseline performance requirement that let ADI to make such product?
The matter for this auto safety is very much depending on other driver. Driving is not a safe task, although I am doing all the best to prevent an accident from happening. Like two hand on wheel, look front, don’t talk, don’t eat, don’t drink, don’t sleep can not prevent it many accidents. It is because other driver made mistakes. All of those safety devices are sensing a very near range, like side, front, and back. The defensive driving is the best way a diver can do. If this kind of technology can help or warn a lack of attention on detail it will be super.