I want to know the characteristic impedance of differential line by ADS2011. But this has something wrong. I hope someone can help me.thanks

I set the parameter like the follow figures.

and I follow the example ( CPW_Diff_lines_Finite_Prj) of the ads2011. I tranfer the 8 ports into 4 ports, and then tranfer 4 ports into 2 ports, and then try to find the characteristic impedance by parameter sweep and optim

the result is 122Ω, but the impedence is 77Ω which is caculated by polar

I set the parameter like the follow figures.

and I follow the example ( CPW_Diff_lines_Finite_Prj) of the ads2011. I tranfer the 8 ports into 4 ports, and then tranfer 4 ports into 2 ports, and then try to find the characteristic impedance by parameter sweep and optim

the result is 122Ω, but the impedence is 77Ω which is caculated by polar

and I have see the example from the forum Microstrip trace Impedance with cross-hatched Ground plane

and I try to find the Zodd, and then find the Zdiff by the equation Zdiff=2* Zodd

but Z(1,1) Or Y(1,1) does not exist on the list of the variable o f S-parameter