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DDC Receiver sensitivity

Question asked by Alex_777 on May 27, 2016
Latest reply on Jun 9, 2016 by David.Buchanan


We are designing DDC receiver (decided to use AD9461) .

We must provide sensitivity above -120dBm  (10 dB SNR / bandwidth  12kHz). To simplify  the  calculations I  take unmodulated carrier.


My preliminary calculations are:

AD9461 SNR = 77 dBFS


After digital down conversion:

SNR Improvement (dB) = 10 x log (Sampling Rate/2x Signal Bandwidth)

SNR Improvement (dB) = 10 x log (122.880e6 / 2x 12e3) = 37dB


SNR summary = AD9461 SNR +  SNR Improvement= 77 + 37 = 114dB


But for sensitivity -120dBm we must have  SNR= 120dB + 10dB= 130dB


1) Tell me please, my calculates is correct?

2) If I can't provide the sensitivity -120dBm on AD9461, what can I do in this case?