This is an extension of this thread, so review first!!
https://www.eevblog.com/forum/testgear/bode-plot-computational-time-for-various-dsos/To add some additional information regarding the Bode Plotting capability we decided to conjure up an experiment to "see" just how good the frequency selectivity of the Bode implementation behaves with large interference sources. This was done with a simple RC LPF (1K and 0.01uF) as DUT.
We directly connected two separate AWGs (SDG2042X & SDG6022X) outputs relying on the 50 ohm output Z to create a summation signal, one AWG (2042X) is controlled by the DSO (SDS2104X+) by LAN and the other AWG (6022X) is Independent.
First off we set the Independent AWG as a Noise Source (PRNS) with Standard Deviation of 1V, and the Dependant AWG to 0.1Vrms.
The Bode Parameters were Decade Sweep from 100Hz to 100KHz, 20pts/dec, 0.1Vrms, with CH1 and CH2 using 10X DSO Probes and 20MHz BW DSO limitation.
First image shows the Bode result without any disturbance from the Noise Source.
Second Image shows result with Noise Source active.
Third shows Time Domain Plot, note the level of the Bode Signal to the Noise Signal (buried within the Noise)!!
Next we changed the Independent "Noise" AWG to 1KHz SineWave at 1Vrms, Bode signal still at 0.1Vrms.
Fourth shows with 1KHz "Noise" Source
Next shows Time Domain Plot, note the level of the Bode Signal (smaller signal) to the 1KHz "Noise" Signal!!
Anyway, this was quickly done just to "See" how things behave, and much more work/effort needs to be applied. Maybe some others might find this useful/interesting and post some results they've achieved.
Edit: Added:
6th with "Noise" source at 10KHz @ 1Vrms
7th with "Noise" source at 10KHz @ 5Vrms!!
8th Time Domain plot of 7th, note the small signal is the Bode signal of interest!!
Best,