[SI-LIST] Re: Lower epsilon achieves lower crosstalk
- From: Michael Greim <mgreim001@xxxxxxxxx>
- To: Young <long.0.yang@xxxxxxxxx>
- Date: Fri, 12 Nov 2010 08:45:03 -0500
simply put, homogeneous media
Google search "stripline crosstalk" and you will find a great powerpoint
presentation from Intel on the topic
titled "class19_crosstalk_overview.ppt"
Best Regards,
Michael C. Greim
And all this science they don't understand
Is just my job six days a week.....
We will either find a way or make one -Hannibal
In the middle of every difficulty lies opportunity -Al Einstein
On Thu, Nov 11, 2010 at 8:10 PM, Young <long.0.yang@xxxxxxxxx> wrote:
> Zhenggang
> Could you tell us why there is no FEXT in the case of stripline?
>
> On Fri, Nov 12, 2010 at 03:25, ZHENGGANG CHENG <zhenggang.cheng@xxxxxxxxx
> >wrote:
>
> > Hi Liu,
> > Xtalk analysis is very different for microstrip and stripline cases, and
> it
> > also depends what xtalk you are talking about such as FEXT or NEXT.
> >
> > For stripline, there is no FEXT, and NEXT proportional to Cm/C. So in
> this
> > case, lower Er, to keep the same impedance, H will be decreased, so Cm/C
> > will be smaller.
> >
> > For microstrip case, FEXT is proportional to Cm/C-Lm/L, and NEXT is
> > proportional to Cm/C+Lm/L. In your case, Lm/L is becoming larger (Lm is
> not
> > changing, L is decreased due to smaller H), Cm/C may be smaller, then
> FEXT
> > will become larger due to lower Er.
> >
> > Zhenggang CHENG
> >
> >
> > On Wed, Nov 10, 2010 at 10:46 PM, Liu Xike <xike.silist@xxxxxxxxx>
> wrote:
> >
> > > We could achieve lower crosstalk by using dielectric with lower
> > > permittivity, while keeping *Z0* as a constant.
> > >
> > >
> > > I'm new in SI, my understanding about this question is:
> > >
> > >
> > >
> > > If we use dielectric with lower permittivity while keeping *Z0* as a
> > > constant.
> > >
> > > We need to reduce *h *to maintain a constant *C*, because *C*>
> > *epsilon***w*
> > > /*h*, and *Z0*=1/*vp*/*C*.
> > >
> > >
> > >
> > > Since *Z0* = sqrt(*L/C*), to keep* Z0* as a constant, the stripe line
> > need
> > > to adjust it?s current distribution to maintain a constant *L*.
> > >
> > >
> > >
> > > Considering the loop area decrease because *h* is reduced, the current
> > > distribution should be more tighter to maintain a constant *L*.
> > >
> > >
> > >
> > > Finally the tighter current distribution on the returning pass results
> in
> > > the reduction of the cross talk.
> > >
> > >
> > >
> > > Are these correct? I will appreciate your help
> > >
> > >
> > >
> > > Best Regards
> > >
> > > ------------------------------------------------------------------
> > > 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
>
>
>
--
------------------------------------------------------------------
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
Other related posts:
