Hi Luciano, Here are a couple of introductory articles that Fangyi Rao and I wrote on S-parameter causality and Kramers-Kronig relation that might be of interest: http://www.rfdesignline.com/howto/222400306 http://cp.literature.agilent.com/litweb/pdf/5990-5266EN.pdf hth -- Colin Warwick Marketing Lead, High Speed Digital Design Flow, Agilent EEsof EDA Blog http://signal-integrity.tm.agilent.com Information Exchange for IBIS Model Users http://www.ibis-user.org ; -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of Luciano Boglione Sent: Saturday, August 21, 2010 7:06 PM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Causality test Hi folks, Is there a "test" that can be executed directly on a given S parameter set that can confirm causality of the network? Put yourself in the best possible conditions (e.g. off the top of my head, frequency ranges from DC to infinity continuously). I'm asking for something similar to a passivity test in the frequency domain. Thanks, Luciano . Sent via BlackBerry from T-Mobile ------------------------------------------------------------------ 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 ------------------------------------------------------------------ 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