Fabrizio Zanella
EMC, Hardware Engineering
171 South Street
Hopkinton MA 01748
[email protected]
508-435-2075, x4645
FAX 508-497-8741
-------------
Original Text
From: "Syed Huq" <[email protected]>, on 6/24/99 5:21 AM:
To: smtp@Eng@EMCHOP1[<[email protected]>]
Cc: smtp@Eng@EMCHOP1[<[email protected]>]
John,
You may not be able to define a circular shape but a diamond shape is
possible.
I will try to send you an example. XFX models the hatched ground quite
accurately.
Regards,
Syed.
>
> Syed,
>
> I use XFX to model the cross hatch also. However I realize that the
meshed
> ground defined in the XFX is only good for rectangle.
> It is quite limited. I asked viewlogic's FAE about diamind or circular
> shapes but got not answer.
>
> How do you deal with this problem with XFX ? Is XFX accurate enough for
> hatch ground?
>
> Best Regards,
>
> John Lin
> CAE Engineer
> Quanta Computer Inc.
>
>
>
> -----Original Message-----
> From: Syed Huq [mailto:[email protected]]
> Sent: Saturday, June 19, 1999 5:09 AM
> To: [email protected]
> Cc: [email protected]
> Subject: Re: [SI-LIST] : Cross hatched planes
>
>
> Hello,
>
> If you are using XFX(2-D from Quad), you can model the cross hatch using
> MESHED_GROUND. For example:
>
> MESHED_GROUND HORIZ_PLANE y: 27.80 29.20 P_X: 15.0 A_X: 10.0 P_Z: 15.0
A_Z:
> 10.0
> MESHED_GROUND HORIZ_PLANE y: 0.000 1.400 P_X: 15.0 A_X: 10.0 P_Z: 15.0
A_Z:
> 10.0
>
> Impedance becomes a function of your cross hatch geometry plus more..
>
> We have done this sort of study.
> Regards,
> Syed.
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Syed B. Huq [email protected] ~
> Signal Integrity Engineer(ELB) ~
> Cisco Systems, Inc. ~
> Ph:(408)525-3399 Fax:(408)526-5504 ~
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> >
> > I have a question regarding high frequency (over 500MHz) signals
running
> > over ground planes that are cross hatched, which is commonly done on
flex
> > circuits. The issue is how to accurately model the characteristic and
> > differential impedance for the flex circuit traces. If, for example, I
> use
> > a 2D field solver (where I assume an ideal ground plane) and am
designing
> > for 100 ohms differential impedance, what percent increase in impedance
> > should I expect if the ground plane will actually be cross hatched?
>
>
>
>
> **** To unsubscribe from si-list: send e-mail to
> [email protected]. In the BODY of message put: UNSUBSCRIBE
> si-list, for more help, put HELP. si-list archives are accessible at
> http://www.qsl.net/wb6tpu/si-list ****
**** To unsubscribe from si-list: send e-mail to
[email protected]. In the BODY of message put: UNSUBSCRIBE
si-list, for more help, put HELP. si-list archives are accessible at
http://www.qsl.net/wb6tpu/si-list ****
**** To unsubscribe from si-list: send e-mail to [email protected]. In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP. si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list ****