How to determine the ADC Resolution for a particular FMCW Radar

Amra1

Newbie
Joined
Dec 29, 2022
Messages
3
Helped
0
Reputation
0
Reaction score
1
Trophy points
11
Activity points
33
Hey!

As for an FMCW radar, the sampling frequency of the ADC should be twice the maximum beat frequency of the signal. but when it comes to ADC size or resolution, how to determine that? Is there any relationship that can help in finding that?
 
Hey!

As for an FMCW radar, the sampling frequency of the ADC should be twice the maximum beat frequency of the signal. but when it comes to ADC size or resolution, how to determine that? Is there any relationship that can help in finding that?
You should know noise floor, bandwidth, SNR of your adc and sampling, after that compute what you need
 

here is an example, assume we connected 12 bit adc to some fmcw radar module. If digitized amplitude saturates at 1 meter distance, then it fall to noise level when distance reaches 20 meters (received amplitude falls by 12 for each distance doubling). Then you csn add radar equation and some formulas link budged calculations. Noise level in this example is dB level of digitized noise signal when there is no target present. For nonquadrature signal probably need highen sampling rate by some amount to make sampling correct amplitude.
 

Attachments

  • IMG_20230516_232307.jpg
    84.7 KB · Views: 103

here is additional example, you can change values in browser:
 

Attachments

  • IMG_20230518_231849.jpg
    140 KB · Views: 89

Cookies are required to use this site. You must accept them to continue using the site. Learn more…