From: Teerada H. <tee...@gm...> - 2008-06-02 08:15:06
|
Hi, I have tried to simulate the circuit with frequency dependent component on QUCS. By passing the "acfrequency" parameter to a variable that represented the component value, the result of variable after AC simulation is ok. However, the analysis result of the circuit was incorrect. For example, with the simple AC voltage source connected with a frequency dependent resistor. I set the value of the resistor to Rv, while Rv = acfrequency in the equation. The Rv plot vs frequency was as expectation. However, the resulted current thru the resistor didn't vary. Seemingly, the resistor became short circuit point instead. Is there any way I can simulate the frequency dependent component with AC simulation on QUCS or this is not supported? I'm looking forward for your help. I've tried to post in the forum but it always shows an error. Best Regard, Teerada Huang |
From: Stefan J. <st...@gr...> - 2008-06-02 08:31:55
|
Am Mo, 2.06.2008, 10:14, schrieb Teerada Huang: > Hi, Hello! > I have tried to simulate the circuit with frequency dependent component on > QUCS. By passing the "acfrequency" parameter to a variable that > represented > the component value, the result of variable after AC simulation is ok. > However, the analysis result of the circuit was incorrect. > > For example, with the simple AC voltage source connected with a frequency > dependent resistor. I set the value of the resistor to Rv, while Rv = > acfrequency in the equation. The Rv plot vs frequency was as expectation. > However, the resulted current thru the resistor didn't vary. Seemingly, > the > resistor became short circuit point instead. > > Is there any way I can simulate the frequency dependent component with AC > simulation on QUCS or this is not supported? > > I'm looking forward for your help. I've tried to post in the forum but it > always shows an error. The component you are looking for is the RF-EDD (Equation Defined RF Device) under "lumped components". In the equations of this device you can use "f" as well as "s" (j*w) as frequency parameters. You cannot use "acfrequency" to vary component values. I hope this helps, Stefan. |
From: Stefan J. <st...@gr...> - 2008-06-03 07:49:20
|
Am Di, 3.06.2008, 09:27, schrieb Teerada Huang: > Hi Stefan, Hello! > Thank you for your prompted reply. I have followed your suggestion, > however, > when I run the simulation, it showed the error message "checker notice, > variable `f' in equation `Ra.Z11' not yet defined > > I've also tried on "s" in the device equation and got the same error in ac > simulation. > > Do I need to declare the "f" or "s" in anywhere to let the program know > that > I'd like to assign the component value dependent on AC sweep? Can you please send an example schematic? Then I can have a look... Cheers, Stefan. |
From: Stefan J. <st...@gr...> - 2008-06-03 08:46:09
|
Am Di, 3.06.2008, 10:25, schrieb Teerada Huang: > Hi Stefan, Hi! > I attach the simple schematic to try on the frequency dependent component. > I > made the RF-EDD as a frequency dependent resistor connected to AC voltage > source. > > The reason I need to simulate the frequency dependent component is that I > want to simulate the acoustic frequency response using lump element > circuit. > All the acoustic analogous circuit components are frequency dependent. > > Thank you for your time. I do very appreciate. The "f" and "s" can only be used inside the equations of the RF-EDD itself. Regards, Stefan. |
From: Stefan J. <st...@gr...> - 2008-06-03 09:05:06
|
Am Di, 3.06.2008, 10:55, schrieb Teerada Huang: > Hi Stefan, Sooooooooooooooorry! > I have tried that also. I put "f" in P11 and P22 inside the equations of > the > RF-EDD > itself. When I run the simulation, it showed > > checker notice, variable `f' in equation `R.Z22' not yet defined > checker notice, variable `f' in equation `R.Z11' not yet defined It is "F" and "S"!!!! Put these into the equations of the RF-EDD. Sorry for this, Stefan. |