varactor model

Hello,
I have made a varactor model in ADS like the one in this tutorial:
http://www.odyseus.nildram.co.uk/RFM...r_Colpitts.pdf
the problem is that when i put this subnetwork into the original design and simulates it ,two errors occur "Undefined parameter used by '.X1.V1'" the other one is "Unresolved references:X1.V1" , i use "parameter sweep" and "transient" analysis where X1 is the varactor name and V1 is the parameter that i change in the varactor which has a value "vcntrl" and vcntrl is the variable that i sweep.

Regards,
redhat

Not that familiar with ADS, but make sure you do something to model the storage capaciatance of the bulk diode. You might have a 0.2 pF diode, but under some large signal conditions it could act 20X bigger capacitance than that.

First open the varztor.dsn. then, go to file menu and select "Design parameter" in the drop down list.

hello boy,
i have done that , V1 is defined as a parameter and its default value is "vcntrl" which is changed from outside the model using parameter sweep, i don't know what is wrong.

hi, redhat
is your set up work ok with HB simulation? i just doubt that transient simulation will not work in some cases. I am used to out an inductor with Q in the transient simulation, it does not work while it work ok in HB simulation.

i don't know, i am not familiar with ADS. what could make such an error?

You might try to test it by changing "transient" analysis to "harmonic balance" analysis. you need to put "osc port" in the harmanic balance analysis, dont forget.

Basically its just a simple S-parameter simulation with parameter sweep option, didnt need HB.

for debuging, you can refer my project file created by ADS 1.5

thanks for your help, the error was because i haven't initialized the "Vcntrl" variable.

Thank for your referance!

Hey Guys
I downloaded the project provided by Sunn. However, I was not able to simulate it . Please help

Which is the error? Do you have problems opening the circuit or just simulating?

Hi
Here are some introductory tutorials on ADS:

http://www.eas.uccs.edu/wickert/ece5...S_session1.pdf
http://www.eas.uccs.edu/wickert/ece5...S_session2.pdf
http://www.eas.uccs.edu/wickert/ece5...S_session3.pdf
http://www.eas.uccs.edu/wickert/ece5...S_session4.pdf

regards

Hi amihomo

Do you have the access to the rest of the course material on the website? please do tell.

Thanks.

Leo

this is the link :
ECE5250 Microwave Circuit Design

hi neo617,

i meant the link :

http://www.eas.uccs.edu/wickert/ece5...s/N5250_15.pdf
some of the useful docs on the website are restricted. It will be great if you have the access.

Does anyone have the password for Mark Wickert's lecture notes? I've been looking for them for years but couldnt view his lecture notes