Re: impedance across ground plane

Nirmal Jain (nirmal@ansoft.com)
Fri, 16 Feb 96 11:34:56 EST

Hi Joe,

The impedance across the gnd plane in high speed design
is due to the inductances and the resistances offered to different
current paths in the plane.

To figure out this impedance you can model your plane
using modeling tools. To effectively model your pcb plane you might
need switching and some placement information.

You can find more information on plane modeling in papers by davidson
(from ibm) I think or in any paper disucssing ground bounce or ssn.

Hope it helps.

Nirmal

>
>Can anyone help this fellow?
>
>----- Begin Included Message -----
>
>To: technet@ipc.org
>Subject: impedance across ground plane
>
>fellow technetters,
>
>We are searching for information on the impedance across the ground
>plane on a pcb. We have some harmonics near 3 Ghz, and would like to
>see if we can reduce the impedance to earth ground through our pcbs,
>and backplanes.
>
>If anyone knows of some sources where we can look up information
>please forward.
>
>thanks in advance
>joez
>
>-----------------------------------------------------------------------------
>Joe Zdybowicz
>CAD Engineer
>FORE Systems
>174 Thorn Hill Road
>Warrendale PA 15086
>email: joez@fore.com
>
>
>
>----- End Included Message -----
>
>

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