Thanks, Hermann! Yes, we introduced a multi-level (little hemispheres on bigger hemispheres) conductor surface roughness model in ADS 2011. You can use it for transmission lines such as Multi-layer Models library or in Momentum. There's a joint Agilent-Cisco MTT MicroApps presentation about it here: http://www.home.agilent.com/upload/cmc_upload/All/MicroAppsRoughness.pdf Best regards, -- Colin Warwick Product Manager for High Speed Digital Agilent EEsof EDA Blog: http://Signal-Integrity.TM.Agilent.com ------------------------------------------------------------------ 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