Question about S-parameter simulation in ADS

In a two-port network simulation, we add term1 at port 1,term2 at port 2. What is the impedance of term1 in the S-parameter simulation? Is it the characteristic impedance or the source impedence?

may be you can edit the port to change the impedence ,and the defauht is 50ohm

I know the impedance can be changed, but what is the meaning of the impedance, is the incident wave's character impedance or the source impedance?

It is the source impedance. Think of it as the 50 ohm (or other) source (and load for reflected waves) impedance that resides within a network analyzer.

It is basically a termination hence the term "term1" etc.. But like was said in the sicussion, it can be considered as the source impedance as well.

Ananth.