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The manual shows the Hybrid’s ports 1-4. The schematic symbol has no numbering. Port 4 is the In/Sum port.
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I cannot say why there is different data with some files that had ac power source Z= “50 Ohm” vs “50” or “50 Ω”. It’s possible I had converted a Qucs file to QucsStudio using a text editor and a character was corrupted. This is something I have done many times before without issue. I can only assume there is a hidden character I cannot see or QucsStudio is treating Z= “50 Ohm” vs “50” or “50 Ω” differently.
Be aware the QucsStudio Hybrid does not indicate what port in the In/Sum port. Look at the amplitude/phase data for the three “identical” schematics. S31 and S41 are different.
Hybrid 180
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SM6PGP
Michael says the 7.05e-31 is “0”. It seems any small number is considered as a “0”. 90 or 180 get calculated as whole numbers however.
It seems the “ideal” Hybrid is not a “symmetrical” model. There is only one port that can be used as the Input or Sum. I can only get your data if I place the Hybrid as shown in your schematic. It would be useful to identify this port on the schematic symbol. I assume this is why you had problems making your amplifier to work.
Attached is two alternate schematics using Hybrid 90/180 where the data is wrong.
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The data for coupled_lines_cpl seems wrong. The phase (S41) is 7.05e-31. The phase difference between the two outputs ports should be 90 deg. Am I to assume 7.05e-31 means 0?
I sent a long winded email about this and included my test files.
I ‘m unsure how to use and phi in the ideal coupler. The default is k=0.7071 and phi=90. When I try to use phi=180, I cannot get any value of k to work.
In addition when testing the ideal coupler, loss and phase data are wrong for 3dB 90deg.
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I only mention the issue because I put the identical circuit into Qucs-S, 5Spice and LTSpice and they ran the circuit. I realize the circuit is not a realistic one but I also tried the usual trick’s of adding series/parallel resistors and still couldn’t get it to run.
I do wonder why Qucs has 4 components in the Ideal Library that don’t work.
Additionally I cannot get Coupler or Hybrid to work properly. I can’t get a simple circuit power combining 2 of the Gain blocks with 2 Couplers or Hybrids to work properly.
They don’t work 100% in Qucs either. In the case of Qucs, ports are swapped in the Hybrid. I also get some odd data power combining 2 of the Gain blocks with the Coupler.
I think some of your models have errors. QucsStudio 3.3.2 generates slightly different models than 2.5.7. For example the BFP420 Spice model uses a transistor with a substrate connection. QucsStudio 3.3.2 has it but 2.5.7 doesn’t.
Follow up:
Edited S_diverse.lib to have two identical components the original Qcoil and a renamed copy Qcoil2. Qcoil2 give an error while Qcoil works.
Why is QucsStudio not allowing me to make user libraries or modify any of the original” libraries to add components?
