I'm working on a frequency mixer project in which two analog voltage signals at two different frequencies (each <5 kHz) are considered. I'd like to add the two fundamental frequencies and return an analog output in real time. Can I do this digitally and how difficult it is compared to an analog approach?

My idea so far includes an ADC with a fast enough sampling rate, Python scipy (for filtering), and DAC for output.

I'm trying to go low cost (<100 bucks). As far as I'm concerned, I don't see a potential problem in this idea as an ADC with Msps can be obtained, the math process is fast enough, and the DAC can also have Msps sampling rate.

But as a chemistry student, I'm no professional at DSP, so please point out some of the potential flaws/drawbacks of this method and tell me if you'd recommend doing this in analog?

Thanks in advance.

  • $\begingroup$ what'sa "DAQ"? $\endgroup$ Jul 3, 2017 at 16:36
  • $\begingroup$ Thanks. I added the clarification. It's an analog to digital converter. $\endgroup$
    – Huy Nguyen
    Jul 3, 2017 at 16:51

1 Answer 1


To answer my own question here for anyone who would like to do something similar, I ended up designing an analog circuit instead of DSP. I used a signal multiplier chip called AD633 to multiply the two frequencies. Then I use a bandpass filter to extract the sum frequency.


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