Characteristic impedance from HFSS

hardyethan said:

hi all,

how can i get the characteristic impedance of a differential line/ differential via from HFSS. Z11 parameter gives you open circuit input impedance. Zot shows the port's terminal impedances.

Or should i have to run two simulations for two models (one with open circuited traces and other with both the traces shorted together) to get Zoc and Zsc. From that i can get Zo=sqrt(Zoc/Zsc). :?:

i did run these simulations and the differential characteristic impedances for differential traces were obtained correctly. But i know there should be some other method to obtain characteristic impedance from models easily.

Correct me if i am wrong! Not so conversant with impedances. :| Any books on this??

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