Hi Samuel, the way to define excitation in 2D extractor and in HFSS is quite different because the first use a quasi-static approach while the second use a full-wave method. In HFSS the user need to assign a port on which the propagating mode is calculated. (TEM in case of the microstrip) HFSS will also calculate port impedance, guided wavelenght and effective permittivity and will take automatically in account all the losses if present. As you know there are several way to calculate the impedance associated to a propagating mode: Zpi,Zpv,Zvi HFSS uses Zpi by default but for aTEM mode Zvi could be more natural choise. The user can ask HFSS to use any of the 3 impedance definition to calculate characteristic impedance; in any case for a 50 ohm line , just to make an example) all the 3 impedance will be really close to 50 ohm. I hope this help, in any case you may want contact an Ansoft AE of your area to get more detailed answer on your question Regards Giancarlo ----- Original Message ----- From: <yf_xie@xxxxxxxxxx> To: <si-list@xxxxxxxxxxxxx> Sent: Wednesday, July 14, 2004 3:01 AM Subject: [SI-LIST] A question in 2D Extractor & HFSS Hi All, I met a problem in HFSS. As before when using Maxwell 2D Extractor to simulate microstrips, I only care about the Characteristic Impedance > Lossy Z0. And it is easy to get this value. Now turns to HFSS, I cannot find Lossy/Lossless Z0 but found Zpi, Zpv, and Zvi impedance. How can I do? Samuel ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu ------------------------------------------------------------------ To unsubscribe from si-list: si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field or to administer your membership from a web page, go to: //www.freelists.org/webpage/si-list For help: si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field List FAQ wiki page is located at: http://si-list.org/wiki/wiki.pl?Si-List_FAQ List technical documents are available at: http://www.si-list.org List archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu