[Solved] Agilent ADS : determining impedance @ one point ??

[chromatik]

Hello all,

Maybe a quite stupid question, but... I'd like to know if it's possible to obtain impedance (A+jB) for a certain point in a simulated S-parameter circuit ?

I got the answer for the input, and the output of a circuit but... for any other point, is that possible ?

Thanks a lot for your help !

Regards

Edit: to be more precise, I would like to know the impedance seen by a component placed in the circuit...

I think I miss something but...
Any help will be appreciated

 

[mickey_melomane]

Agilent ADS : determining impedance @ one point ??

hmmm... why dont you place a port at the desired node, and measure the reflection coefficient. From that you can obtain your Impedance.

Sidharth

 

[chromatik]

Agilent ADS : determining impedance @ one point ??

That was my first approach, in fact.
But I noticed that the impedance depends on the value of the impedance of the port.
If I put a 50 ohms port, I got a value, and with a 10kohms port, another...

... maybe a denormalization problem I don't understand ?

Edit: I understand the reflexion coefficient depends on the source load, but I do not, when I'm looking in the Smith chart: if I understand well, the displayed value is normalized to the input port value, so it should not change ?

Where the hell am I wrong ??

Added after 4 hours 5 minutes:

... sometimes, searching worth the price you pay for

When you start the simulation, then obtain the Smith chart, then after mark for a certain frequency...

... then left double click on the info box (with frequency you picked up), goto Smith tab, and select which Z0 you're using !
By default, "normalized".

There was my problem !

Hope this could be useful for somebody else

 

[hop83]

Re: [Solved] Agilent ADS : determining impedance @ one point

Hi everybody, my question regarding the design of a matched network. It t is possible in ADS to design a network with a known value of gamma L and gamma S?
If not, at least how can I measure the value of source reflection coefficient and load reflection coefficient for a given network?