# How can an SDR recover a high-frequency signal?

How can software-defined radios operate at high frequency?

The Nyquist rate dictates that you need to sample at twice the frequency to fully recover the signal. If my signal of interest is modulated at $$2.5 \,\rm{GHz}$$, doesn't my SDR need to sample at $$5 \,\rm{GHz}$$ to fully recover and demodulate the signal of interest?

• Bandwidth and frequency are not the same thing in this case – Stanley Pawlukiewicz May 15 at 18:20
• Nyquist does not dictate 5 GHz. Your bandwidth is not 2.5 GHz, it is much smaller. What is the bandwidth of your signal of interest? Read this article wescottdesign.com/articles/Sampling/sampling.pdf – Ben May 15 at 18:38