Patrick, I'm sure we would too. Your constraints matched the problem description, mine did not. I guess I was thinking about the simplest and least expensive way to build it. Ken -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Zabinski, Patrick Sent: Thursday, August 05, 2010 11:36 AM To: Ken Cantrell; Zabinski, Patrick; Haller, Robert; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Insertion Loss, Return Loss, ILD, UNi versus Dual stripline > If you had equal dielectric thicknesses and constant permittivity as > suggested in my previous post, the dual-strip would have less > S21 wouldn't > it? ... Yes; we would. However, I considered Robert's statement that "... and they are the Same Copper Geometry (say 4 mil line/7 mil space) and have the same impedance, same DC resistance ...", which I took to imply that he changed the dielectric thicknesses to compensate for the constant line geometries. I believe the posed question led us to apply different interpretations/constraints, thus we ended up with different answers. If we assumed the same conditions, we probably would end up with the same result. Pat ------------------------------------------------------------------ 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