Hi Jun, You can verify it by translating your data into time domain and you may find something. Thanks and Regards, Leon From: jun li [mailto:lijun_hit@xxxxxxxxx] Sent: Thursday, June 24, 2010 11:31 PM To: si-list@xxxxxxxxxxxxx; Leon Wu Subject: Re: [SI-LIST] Re: Port extension with VNA Leon, Thanks for patient clarification. My question is to port extension which calibration is a better way. TRL calibration is more accurate for removing fixture from measurement, but I can't verify this from our skew measurement. Because the skew value got from TRL calibration is too big to be true. Thanks Jun --- On Wed, 6/23/10, Leon Wu <Leon.Wu@xxxxxxxxxx> wrote: From: Leon Wu <Leon.Wu@xxxxxxxxxx> Subject: [SI-LIST] Re: Port extension with VNA To: "jun li" <lijun_hit@xxxxxxxxx>, si-list@xxxxxxxxxxxxx Date: Wednesday, June 23, 2010, 11:52 PM Hi Jun, Some papers demonstrate the TRL cal is more accurate than SOLT cal in IEEE but it still depends on how the fixture was designed. Maybe you can search the IEEE web site to get the papers. You can search the application notes in Agilent web site as well. They have some paper available in the web site. I ever seen a comparison table which Agilent released before. Thanks and Regards, Leon From: jun li [mailto:lijun_hit@xxxxxxxxx] Sent: Thursday, June 24, 2010 12:28 PM To: si-list@xxxxxxxxxxxxx; Leon Wu Subject: RE: [SI-LIST] Port extension with VNA Leon, Many thanks for your reply. Since you mentioned there is much difference for long fixture with these two calibration methods, which one is more accurate? Is there any paper talking about this? Thanks Jun --- On Wed, 6/23/10, Leon Wu <Leon.Wu@xxxxxxxxxx> wrote: From: Leon Wu <Leon.Wu@xxxxxxxxxx> Subject: RE: [SI-LIST] Port extension with VNA To: "jun li" <lijun_hit@xxxxxxxxx>, si-list@xxxxxxxxxxxxx Date: Wednesday, June 23, 2010, 7:02 PM Hi Jun, Based on my experience, 'port extension' function is just for the phase but not for the magnitude. And if your fixture is long enough or have large discontinuities, the difference becomes large. Thanks and Regards, Leon -----Original Message----- From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On Behalf Of jun li Sent: Thursday, June 24, 2010 9:34 AM To: si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Port extension with VNA Hi, allIs it necessary to use SOLT calibration for port extension? In theory, TRL calibration should work, too. But we got far different value with these two different calibration method. ThanksJun ------------------------------------------------------------------ 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 ------------------------------------------------------------------ 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