How to change the impedance of a lumped port in IE3D?

Hi, everyone.

I want to know difine lumped port in IE3D.
Is Basic port impedance 50Ω in IE3D?
How can i change the impedance of port?
I want to match the antenna impedance to the chip impedance(6.7Ω-197Ω).

thank you..

The s-parameters are always normalized to 50-ohms in simulation because we want to make the s-parameter file to be compatible with Touchstone. However, you can re-normalize it to other ohms when you display teh s-parameters. When you do optimization, you can optimize s-parameters normalized to other ohms.

Thanks Jian

I tried to renormalize the characteristic impedance in IE3D, but i couldn't renormalize a part of imaginary.
I want to match between an antenna and a chip.
the chip's impedance is 6.7-j*197 ohm.

so i tried to renormalize the result of IE3D in ADS(by agilent).
I used the term which has 6.7-j*197 ohm.
Is method correct?

Complex normalizaiton impedance (Zc) is not good. There are many issues involved. We know that Gamma = ( Z - Zc ) / ( Z + Zc ). When Z = Zc and Zc is real, we get Gamma = 0 meaning no reflection. However, if Zc is a complex value, the formula for Gamma is doubtful. You can not expect Gamma = 0 with Z = Zc. I know ADS uses some revised formula on the Gamma when complex Zc. Similar formula is implemented in the MODUA 11 on IE3D 11. However, it is hard to say the revised formula can yield better result. Basically, when complex Zc is involved, waveguide theory is no longer rigorous. Basically, the waves inside a waveguide can no longer be separated into incident and reflected waves when complex Zc is involved. If you want to use complex Zc, you need to use it with care. I don't think any software can guaranteee you accuracy with complex Zc because the theory underneath complex Zc already can not guarantee preciseness.