Arbitrary load in ADS

[cnm]

Help needed to create an arbitrary load in ADS that has a reflection coefficient magnitude =1, so I can sweep the phase.

In other words, the normalized load is on the rim of the unit Smith chart.

Thank you!

 

[pancho_hideboo]

Use "S1P_Eqn", "Z1P_Eqn" or "Y1P_Eqn" with equation describing impedance you want.
S1P Eqn to S6P Eqn (1- to 6-Port S-parameters, Equation-Based) - ADS 2009 -*Agilent EEsof Documentation Center
Z1P Eqn to Z6P Eqn (1- to 6-Port Z-parameters, Equation-Based) - ADS 2009 -*Agilent EEsof Documentation Center
Y1P Eqn to Y6P Eqn (1- to 6-Port Y-parameters, Equation-Based) - ADS 2009 -*Agilent EEsof Documentation Center

If you never run transient analysis, you can use "Term" with equation describing impedance you want instead of "S1P_Eqn", "Z1P_Eqn" or "Y1P_Eqn".
Term (Port Impedance for S-parameters) - ADS 2009 - Agilent EEsof Documentation Center

For example,
if you use "Z1P_Eqn" or "Term", set Z[1,1] or Z like following.
Gamma=polar(rho, phase_deg)
Z0=50
Z[1,1]=Z0*(1+Gamma)/(1-Gamma)

if you use "S1P_Eqn", set S[1,1]=polar(rho, phase_deg) and Z[1]=50.

 

[cnm]

Thank you Pancho for the wonderful tips. It is indeed very helpful.

For Z1P_Eqn, I have to sweep from a small non-zero value to a number slightly less than 360 to get around the "divide by zero" error.

 

[pancho_hideboo]

For Z1P_Eqn, I have to sweep from a small non-zero value to a number slightly less than 360 to get around the "divide by zero" error.

It is very natural since you set rho=1.0.

Why don't you use "S1P_Eqn" ?

BTW, if you use "S1P_Eqn" or "Z1P_Eqn" in Transient Analysis, you have to pay attention to a causality of your impedance expression.
See The Designer's Guide Community Forum - usage *of "port" from analogLib

 

[cnm]

I did try all the options you suggested.

The impedance causality is very interesting...Do you have more background or basic info on the causality?

 

[pancho_hideboo]

The impedance causality is very interesting...
Do you have more background or basic info on the causality?

See "Dealing with Noncausal Frequency Responses" in Troubleshooting a Transient-Convolution Simulation - ADS 2009 - Agilent EEsof Documentation Center

 

[cnm]

Thank you so much for the very cool stuff, Pancho! learned something new today.

 

[michele.kozlovic]

Touchstone File Format Specification Rev 1.1

Hi I suggest follow this link:

**broken link removed**


Have a nice day