Is there any low budget alternative for Bode100?
Our Key purpose is to design EMI filters and analyze power supplies.
We are a start-up company and cannot afford to invest much as of now.
Bode100 is very good low frequency VNA with large bandwidth and dynamic range.
It also has many specialistic modes and measurements.
It is industry benchmark, and in a perfect world I would have one..
That being said, scope equipped with FRA option will do most of the work on PSU and filters (Picoscope with FRA4PicoScope can be used with more than 8 bit Picoscopes). They will not do impedance analysis and other stuff BODE100 can, but they will do Bode plots.
Keysight has good FRA on 3000T series, Siglent have very good one too, even on entry level scopes and generator combinations. SDS2000X+ is a combination of a good scope with built in AWG and FRA all in one.. Rigol also have FRA but that one is a bit unfinished.
I ran Keysight 3000T, Siglent and FRA4PicoScope with 3 different Picos and they all gave exactly the same results when measuring some DUTs. Speed was comparable too. It gets slowish if you pick too much points, but you can always start with less points per octave, do sanity check and if it looks good run a detailed plot for final result..
Mostly you will see less dynamic range (with 8 bit scopes) but that is mitigated with variable levels and autoranging on scopes. Mostly, biggest difference you will see is that these FRA on scopes are slower than BODE100. They take a bit more time to finish the plot. Most of the time plot will be as usable as one from Bode100, if frequency ranges are sufficient.
I did run FRA on scopes with more than 8 bit (12 and 16bit) and then results are very close to what Bode100 would provide.
One more thing is that you will need injection transformers and/or amplifiers/active injectors. Those you will need no matter what you choose to run the analysis with. Some of these can even be DIY(with good result, but with some effort) or even improvised in a pinch by using various signal/pulse transformers or even common mode chokes. There are several topics here where members demonstrated some very good designs...