How to determine the ADC Resolution for a particular FMCW Radar

[Amra1]

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?

 

[Andrew77]

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

 

[Georgy.Moshkin]

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.

 

[Georgy.Moshkin]

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

Math Notepad

Math Notepad is a web based editor to do mathematical calculations and plot graphs. It supports real and complex numbers, matrices, and units.

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