Hello all, I have a question on how the SDD and SCD series of measurements are made. Never having actually performed these measurements I did a bit of reading and am unclear on the process. What I understand is (at least from one manufacturer of test equipment) that the 4 x 4 single-ended S-parameters (S11 to S44) are measured. A built-in function then converts them to the mixed mode S-parameters. My question: For SDD11 are the trace pairs driven with a differential signal (in the software?). By the same token for the SDC measurements are the traces driven with a common signal? Thanks! Best Regards Charles Grasso Compliance Engineer Echostar Communications (w) 303-706-5467 (c) 303-204-2974 (t) 3032042974@xxxxxxxxx<mailto:3032042974@xxxxxxxxx> (e) charles.grasso@xxxxxxxxxxxx<mailto:charles.grasso@xxxxxxxxxxxx> (e2) chasgrasso@xxxxxxxxx<mailto:chasgrasso@xxxxxxxxx> ------------------------------------------------------------------ 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 Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu