I am performing some simulations for FMCW radar for target detection. I am working with a dechirp on receive system. Therefore, the target distance can be determined from the Intermediate Frequency or beat frequency.

Fbeat = Chirp_Rate x 2 x Target_Dist / c

I realised that the maximum theoretical distance that can be detected by the radar is determined by Fs (sampling frequency). What is the relationship between the two? Is there a particular formula or concept that links both parameters?