I may be wrong, but:
* is nanoVNA not derived from the EU1KY antenna analyzer?
No, EU1KY is quite a bit different
* in which case, mixers basically mix down to DC (no IF)
- bandwidth limited by RC networks into ADCs with 5.5 MHz gain bandwidth (at
100 kHz)
in any case, you have a limited resolution bandwidth even if it is not apparent as a physical filter circuit.
although I think there must be a lowpass filter after the mixer (zero IF)
The question is how wide/narrow is it?
On Wed, Jul 10, 2019 at 2:57 PM amirb <amir.borji@...> wrote:
certainly they are not implementing a narrow FFT bandwidth filter in the DSP
"DSP math libraries provided by ARM, with FFT code highly optimized for speed"
I didn't get where this quote is coming from but it does not mean the NanoVNA designer has
implemented a narrow band low pass filter (resolution BW) in DSP for small spans. Maybe he can explain it...
