Hi, Binchuan: Removing the ground plane for differential pair will suppress the even mode. Basically, the even mode will not be propagating. Its energy will not be transmitted. The even mode signal, which is considered as 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 > [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 > deserved or not? > > > > I am confused that I read some book about remove Ground under > Differential could reduce the induced Current from Differential pair, > but the question is how we could control its 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 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 > > ------------------------------------------------------------------ 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