ADC – Nyquist Zone and Sub Sampling

adcnyquist plot

I am trying to design a system to sample an RF signal using a 10MSPS 12 bit ADC (ADC12010CIVYX/NOPB). During frequency planning I observed that, to get a proper sample with out aliasing the input frequency should be at 9Mhz (or 19,29,39 etc) i.e. in the second (or even) Nyquist zone. My problem is that the RF signal is at UHF (409 MHz, so it would fall in the 82 nd Nyquist zone) and I would to know if there is an upper limit for the Nyquist zone that can be safely under sampled by the ADC.

Any help is greatly appreciated.

Thanks.

Best Answer

Take a look at the datasheet:

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So about 100 MHz, give or take depending on how much SNR you want to give up. For 450 MHz, you probably want to buy the faster (pin compatible) version of the chip here:

https://www.ti.com/product/ADC12L066

Which lists:

enter image description here

So that would enable you to subsample 409 MHz with nearly full sensitivity.

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