Hello Ratchet man, Nice to hear from you. Hope you will be contributing to this group on regular basis. I took your class in Boston couple of years ago. Last week there was a discussion about guard traces and I remember you had a very strong opinion about them. Can you please share your thoughts about the guard traces with this group. Regards Ibrahim Khan -----Original Message----- From: Ritchey Lee [mailto:leeritchey@xxxxxxxxxxxxx]=20 Sent: Monday, July 29, 2002 11:07 AM To: jian@xxxxxxxxxx Cc: binchuan2000@xxxxxxxxxxxx; si-list@xxxxxxxxxxxxx Subject: [SI-LIST] Re: Remove Ground underneath Differential signal is deserved or not? Binchua, You don't ever want to remove the ground plane from underneath a differnetial pair. Many more negative side effects result than the alleged common mode energy might ever cause. Lee Jian X. Zheng wrote: > Hi, Binchuan: > > Removing the ground plane for differential pair will suppress the even > mode. Basically, the even mode will not be propagating. Its energy=20 > will not be transmitted. The even mode signal, which is considered as=20 > noise, will be reduced in your circuit. Thanks! > > Best regards, > > ---------------------------------------------------------------------- > - > Jian-X. Zheng, Ph.D > Zeland Software, Inc., 48890 Milmont Drive, 105D, Fremont, CA 94538, U.S.A. > Tel: 510-623-7162, Fax: 510-623-7135, Web: http://www.zeland.com > --------------------------------------------------------------------- > > > -----Original Message----- > > From: si-list-bounce@xxxxxxxxxxxxx=20 > > [mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of binchuan2000 > > Sent: Thursday, July 25, 2002 7:20 PM > > To: si-list@xxxxxxxxxxxxx > > Subject: [SI-LIST] Remove Ground underneath Differential signal is=20 > > deserved or not? > > > > > > > > I am confused that I read some book about remove Ground under=20 > > Differential could reduce the induced Current from Differential=20 > > pair, but the question is how we could control its=20 > > impedance(Differential > > impedance) although Differential doesn't reference to Ground. If I > > follow this content to REMOVE Ground under Differential pair how > > could I control its Zodd impedance and its Zdiff impedance. Does it > > will generate any other problem and if it does, why some textbook > > advise it? > > > > Remove Ground is worth or not for Differential signal ? > > > > > > > > Thanks, > > > > > > > > Binchuan.Wang > > > > ------------------------------------------------------------------ > > To unsubscribe from si-list: > > si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject=20 > > field > > > > or to administer your membership from a web page, go to:=20 > > //www.freelists.org/webpage/si-list > > > > For help: > > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > > > List archives are viewable at: > > //www.freelists.org/archives/si-list > > or at our remote archives: > > http://groups.yahoo.com/group/si-list/messages > > 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:=20 > //www.freelists.org/webpage/si-list > > For help: > si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field > > List archives are viewable at: > //www.freelists.org/archives/si-list > or at our remote archives: > http://groups.yahoo.com/group/si-list/messages > Old (prior to June 6, 2001) list archives are viewable at: > http://www.qsl.net/wb6tpu -- Binary/unsupported file stripped by Ecartis -- -- Type: text/x-vcard -- File: vcard.vcf -- Desc: Card for leeritchey@xxxxxxxxxxxxx ------------------------------------------------------------------ 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 archives are viewable at: =20 //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages=20 Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu =20 ------------------------------------------------------------------ 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 archives are viewable at: //www.freelists.org/archives/si-list or at our remote archives: http://groups.yahoo.com/group/si-list/messages Old (prior to June 6, 2001) list archives are viewable at: http://www.qsl.net/wb6tpu