I'm designing an homebrew RF spectrum analyzer.
Controlling the analyzer will be done using USB which is converted to UART using an FTDI chip.
My concern is that noise (probably common-mode) will be injected from the PC (USB/UART) and affect the SNR of my spectrum analyzer. I know that PCs are very noisy.
My idea was to use some separation(probably an optocoupler) to completely separate the PC from the spectrum analyzer.
Does anybody know whether this is necessary or not?