Calculation of Impedance

[alacrity]

Hello Everyone,

Can any one please help me to finding out the Impedance at any point in RF circuit. suppose i want to calculate this at the output port (or at the output of inductor) . and want to know it using ADS software.






THanks for help in advance

 

[c_mitra]

You need two points between which you want to calculate the Z. Use the conventional ideas for resistors and capacitors (and inductors) but use j (or -j; with omega as the case may be) for the reactive components. Once you get the final value, you simplify to Z=R+/- jX.

You always say Z between points A and B. Without this information, it is not possible to get the impedance value. In your case, I guess one point will be the ground. If you do stepwise, it is simple.

 

[pancho_hideboo]

suppose i want to calculate this at the output port

Simply do S-Parameter Analysis.
Input impedance can be evaluated by "zin()".
See **broken link removed**
https://www.edaboard.com/threads/352410/#2

(or at the output of inductor).

Place "Term" at output of inductor.
Then use "zin()".

If you can use following, you can evaluate interstage impedance.
**broken link removed**

 

[Terminator3]

Interesting, hope such useful thing like SP probe will be implemented in Qucs someday (or maybe it is already? did not found it). As i learned many matching examples from books, there is often Gout,Gin,Gs,Gload. Did not know it can be done without cutting in ADS.

 

[pancho_hideboo]

Interesting, hope such useful thing like SP probe will be implemented in Qucs someday (or maybe it is already? did not found it).

Concept of Interstage SP-Probe is very old.

https://www.designers-guide.org/Forum/YaBB.pl?num=1049348496/2#2

You can create your own Interstage SP-Probe easily in SP-Analysis of any simulator.

However you can get Interstage Impedances(Zleft and Zright) by AC-Analysis in any SPICE Type Simulator.

https://www.designers-guide.org/Forum/YaBB.pl?num=1221012939
https://www.designers-guide.org/Forum/YaBB.pl?num=1240334878/18#18
https://www.designers-guide.org/Forum/YaBB.pl?num=1240334878/25#25
https://www.designers-guide.org/Forum/YaBB.pl?num=1240334878/29#29

As i learned many matching examples from books, there is often Gout,Gin,Gs,Gload.
Did not know it can be done without cutting in ADS.

What do you want to mean ?
Such concepts are all very easy.
They are no more than easy linear algebra.
If you can understand back ground theory of them correctly, you can utilize them in any SPICE Type Simulator, even if it does not have SP-Analysis.

 

[alacrity]

Thanx pancho_hideboo.
i am just using term at that end and on smith chart when i am ploting s22, some value of impedance i am getting

Thanx C_mitra

- - - Updated - - -

thnx every one for reply