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Viewing 9 posts - 1 through 9 (of 9 total)
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  • in reply to: Junk Messages #7626
    Enki
    Keymaster

    We are working on cleaning all the spam from the forum and we´ll try to delete the new unwanted post as soon they are published.

    in reply to: Temperature sweep! #7497
    Enki
    Keymaster

    Every component except for OP1 in your sch has a parameter called “Temp”. You can create a variable to change the operating temperature by tunig, sweep or optimization. I´ve never use it, so I don´t know which is the performance will be affected.

    in reply to: Need help with s-par simulation #7496
    Enki
    Keymaster

    Can you attach the project you are working on?

    in reply to: The forum is full of spam #7495
    Enki
    Keymaster

    I wouldn´t mind to collaborate.

    Which´s the software development stage? Normally in Open Sourse you can get an idea but in the case of QucsStudio is more difficult to know.  Please, don´t get me wrong, I like QucsStudio and I try to use it as an alternative to other commercial solutions but I´m willing to see which is the next step.

    in reply to: QucsStudio training? #6833
    Enki
    Keymaster

    Hi,

    I am an Ph.D. and RF engineer who is trying to move to open/free software for design and simulation. I find QucsStudio very interesting and I see it has potential. I would like to participate in teaching and problem solving to improve the software.

    Please, contact me if you are interested.

    in reply to: parameter sweep with >1 Parameters #6826
    Enki
    Keymaster

    Hi Carsten,

    There is an indirect way to do it with Matlab or octave. You can generate a netlist from your schematic with Simulation\Show Last Netlist or shift+F5, and save the file as a txt document.

    Then flowchart would be something like this:

    1. Load the file in Matlab or Octave
    2. Run the simulation with a for loop to go through the lookup table
    3. Modify the lines where the capacitor and resistor are to introduce the values you want in each step of the loop
    4. Read the ‘dat’ files with the S parameters from simulation
    5. Process data in a convenient way for you

    I’ve done it in the past for other circuits and it works well. Find attached the matlab functions that will help you to run QucsStudio and read the S-parameters. I built them from the information I gathered time ago in this forum so I am not the original author, I just put the information together for my needs.

    Remember to share the solution when you implement it 😀

     

    • This reply was modified 10 months ago by Enki.
    Enki
    Keymaster

    Hi,

    Try ‘lossy_inductor.sch’ from the Simulation_AC example project.  I ran it myself and it works but I can not make it run in your schematic.

    I hope it helps

     

    in reply to: parameter sweep with >1 Parameters #6810
    Enki
    Keymaster

    Hi Carsten,

    Is this what you want to achieve?

    Parameter sweep example

    • This reply was modified 10 months ago by Enki.
    in reply to: How can I run EM simulation from Matlab/Octave? #6808
    Enki
    Keymaster

    Hi Carsten,

    I wanted to try the QucsStudio EM capabilites with a simple design: end-coupled half-wavelength bandpass filter. One of the task I want to perform for the filter design is to model the gaps between the resonators to calculate their length and link it to the lowpass prototype.

    How? 

    I created a simple pcb layout with two copper strips and a gap separating both of them. After that, I need to change the gap width, take the s-parameters from the simulation, extract the capacitor pi-model and create a table that relates the lowpass admittance inverters with the EM simulation.

    I also need to do a de-embbeding for a more accurate modelling.

    By been able to manipulate the layout and run the EM simulation I could automate the process with a matlab/octave script.

    What did I get?

    I got it with the .sch and TL components but I want a more accurate simulations with the EM option.

    What I can’t do?

    • De-embedding
    • Run the netlist file from a pcb layout using a Matlab/octave script

    I’ve included the project with the schematic and layout. You can generate the netlist from both and see they have different formats. When I try to launch a simulation with qucssim.exe it does not work. I believe I could do it by calling qucsfdtd.exe but I don’t know how. I guess that the right person to answer that is Michael Margraf.

Viewing 9 posts - 1 through 9 (of 9 total)