The OP mentioned scope and DAQ front ends, which might imply high impedance. Here's where the DSO and AWG might be a better choice that a VNA, which usually are centered around low Z of 50 ohms.
Yes, I am thinking more of high impedance amplifiers, like this small design:
https://www.eevblog.com/forum/projects/measuring-switch-mode-supply-noise-hp461a-replacement-ada4895/msg4652395/#msg4652395But where do you see the problem with 50 ohms? High Z input can be terminated with 50 ohms (input noise changes of course, but that's not relevant here). Output needs to be capable of driving a 50 ohms load, which might be more of a problem. I had to include cable drivers in my "HP461A" LNA design.
I imagine beyond 120 MHz with a HiZ system good results might be difficult to obtain and much less so for a proper 50 Ohm impedance matched arrangement.
I agree, that's what I wrote "few 100 MHz", which I think should be achievable with proper layout.
Is 120 MHz enough ?
SDS2202X-E with SDG2122X.
To 1.5 GHz, SVA1015X Plus.
Interesting options. As I wrote I just bought my RTB2K and certainly will not replace that. SDG2122X: Nice, but a bit limited at 120 MHz.
What about the SDG6022X: Can it be "upgraded" to 350 or 500 MHz as well? EDIT answered by tautech
SVA1015X lists "discontinued" at Batronix. Tons of other options though:
https://www.batronix.com/shop/siglent/all-spectrumanalyzer.htmlHowever usable are VNA functions in these "classical" SA?
Also, I own already a HMS1000 spectrum analyzer (no TG) I purchased for EMC precompliance, would need to get rid of that first (market value probably near zero due to Chinese competition and lack of magic R&S label).