SAMTEC had a really good paper about taking measurements of non 50Ohm devices. Ther used minimum loss pads as well as gating. Both has advantages and disadvatanges, depending on the bandwidth and application. http://www.samtec.com/Technical_Library/reference/articles/pdfs/DesignCon2009_Non-Standard_Impedance.pdf BR Gert -------------------------------------------------------------------------- Absender ist HARTING Electronics GmbH & Co. KG; Sitz der Gesellschaft: Espelkamp; Registergericht: Bad Oeynhausen; Register-Nr.: HRA 5596; persönlich haftende Gesellschafterin: HARTING Electronics Management GmbH; Sitz der Komplementär-GmbH: Espelkamp; Registergericht der Komplementär-GmbH: Bad Oeynhausen; Register-Nr. der Komplementär-GmbH: HRB 8808; Geschäftsführer: Torsten Ratzmann -----Ursprüngliche Nachricht----- Von: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] Im Auftrag von ji-fong_lim@xxxxxxxxxxx Gesendet: Dienstag, 24. Februar 2009 08:05 An: si-list@xxxxxxxxxxxxx Cc: ji-fong_lim@xxxxxxxxxxx Betreff: [SI-LIST] How to obtain accurate S11 for 75ohm Zo DUT using Network Analyzer? Hey SI/MW Expert, How to obtain accurate S11 for 75ohm Zo using Network Analyzer? Currently, I have a 75ohm characteristic impedance DUT which need to perform S11 measurement using network analyzer which have 50ohm impedance internally. From my basic understanding of network analyzer measurement technique, the DUT has to match its respective termination. For my case here which is 75 ohm DUT, it should interconnect to another 75 ohm termination of network analyzer in order to obtain S11. I have perform such configuration inside ADS simulation model setup by having 75ohm termination at the front and back portion respectively towards 75ohm DUT characteristic impedance. Is this S11 simulation result considered appropriate to emulate a 75ohm termination at network analyzer? Cheers, Ji Fong ------------------------------------------------------------------ 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 technical documents are available at: http://www.si-list.net 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 technical documents are available at: http://www.si-list.net 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