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That sounds tough. I didn’t had similar problems. Probably only Michael can help.
What windows version are you using? e.g. win10 Pro ?H? Maybe that’s a useful info for Michael.
Could you try to move the complete qs program folder to another pc and try it there?
You could also try it with an “empty” .qucs folder (just rename .qucs into .qucs_old and create a new empty .qucs folder)
If that helps, you can populate the .qucs folder with the stuff from .qucs_old step by step and see when it failsCould you provide one of the “evil” 😉 schematics?
If you start qs from the command line, is there a message after the crash?
i wanted to convert the schematic that was posted here just for fuN.
h t t p s ://sourceforge. <remove blanks> net/p/qucs/discussion/311050/thread/8e840b8f96/
tbh, it looks quite insane and I wanted to check if QS could do it.
Conversion seemd fine, but QS cannot open it, claiming “Wrong property format”
Is your converter still working for the newest QS version?
I just noted, my variable abs_s11_min is negativ!
It seems to be the real value of S[1,1] at the minimum of abs(S[1,1])
> Concerning the “Save as…” action, the file appears in the “Content” view, but at the end of the list. So, I will change this and sort it to the correct position.
I just checked. It does not in my case.
– project opend
– content tab selected.
– open a schematic (already part of project) and “save as..” -> not in content tag anywhere
– save a new schematic -> not in content tag anywhere
– double click project in project tab again -> all are now visible in content tab.>Concerning the “Projects” tab, I think it would be better to allow project folders being drag’n’dropped into the list directly. A external file explorer won’t be needed anymore.
Well, one would still need a file explorer to drag-n-drop from.Merry Christmas!
>I do not know what is the correct behavior, but can I assume that QUCSSTUDIO is correct?
I don’t know. You could post this in one of these forums:
https://www.edaboard.com/#analog-design.10
I asked an rf question some while ago and got some very knowledgeable answers.FYI The repetetive “dips”in the S11-shape – I think – originate from fractional reflections at discontinuities (e.g. change from port to microstrip). If the discontinuities are n * lambda/2 apart, they cancel each other out and you get a perfect match (very negative S11 value)
your formula must be wrong. At resonance frequency (e.g. 25pF / 67 nH at 123MHz), Z is a very high ohmic (real) value. I don’t see that in your plot.
compare with figure (2): L at resonance should be 1/(omega^2*C). This corresponds nicely with the chain of peaks.
> When port impedance and line impedance match.
This sentence makes no sense. Maybe your text is mis-formatted?I am curious: The differences seem marginal (on S11 levels of ~-70 dB). What kind of a circuit do you have where this is relevant?
Maybe its an effect of higher order modes in the microstrip: https://www.microwaves101.com/encyclopedias/microstrip
I think they should not be present with your freq/substrate spec, but maybe the onset of them is visible on these tiny power levels. And maybe the software packages use different models that include these modes or not.You could 3DEM-model it. Check the EM simulation examples on the qucsstudio website.
.. on the other hand, the optimizer algos are not limited in resolution and there should be a clear gradient towards the maximum inductance value.🤔
indeed, if the parameter space is sampled too sparse, a lot of local maxima appear
Attachments:
CST agrees more or less w/ qucs.
maybe sonnet ist buggy 🙂 ?
