# Why is there no variation caused by this swept parameter?

I quite like Qucs now that I more or less have the hang of it. Unfortunately, I can't figure out how to get a parametric sweep working.

I'm running an AC simulation on this circuit:

For now I'm not asking on how to improve or fix this circuit; solely on how to fix parametric sweep simulation.

The output of the simulation is shown in this table:

The gain is not being affected by the inductor sweep when it most certainly should be. How do I fix the sweep?

• You need to set the inductance of one of your inductors to have the value Lant. (And probably make a variable definition so the model will still be valid when you aren't running the sweep) – The Photon Jun 5 '18 at 18:20
• Meaning, you have an inductor with designator Lant, but its inductance is 10.042 uH. You probably should change its inductance to be Lant instead. – The Photon Jun 5 '18 at 18:21
• Caveat: I don't use Qucs, but I do use ADS, which is the commercial tool that Qucs seems to be trying to copy. – The Photon Jun 5 '18 at 18:22
• @ThePhoton OK. I'm unable to see where I make a variable definition? – Reinderien Jun 5 '18 at 18:22
• In ADS, there's a "variable definition" object you add to the schematic, similar to the equation object in your design where you define G. – The Photon Jun 5 '18 at 18:23

As @ThePhoton indicated, the proper way to use a parametric variable is to write a variable name in the Parameter Sweep param and to write the same variable name instead of a constant value in the component field that you want to sweep; i.e.: