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Port ground reference in EMPOWER

Question asked by JERRY_MARKETOS on Nov 17, 2004
Port ground reference in EMPOWER

The following information applies to "normal" ports placed at the Empower analysis box walls.

Normal EM ports typically need the ability to reference some ground plane either above or below.
If appropriate ground plane does not exist, the result can be warnings or errors such as
"too thick media layer above / below...." or other messages.

Conditions that can bring this about include:
>Having both the top cover and bottom cover defined as open (Electrical, with surface Z of 377).
>Having a metal layer of ground plane, in which a polygon "pour" has been made
(sometimes the edges of the pour may not register as grounded planar entity which touches the box wall)

Often this condition can be addressed without much effort by simply drawing a metal rectangle on a metal
layer directly below the EM port(s).  (Of course there needs to be a dielectric layer between the EM port metal
layer and the "ground" metal layer.  The rectangle should touch the analysis box wall (so it is registered as
being grounded) and should occupy the area directly beneath the port, extending out at least two grid
cells into the analysis box.  If the layer directly below the EM port happens to be a poured polygon, you
can do the exact same thing described above, just place the new metal rectangle directly on the poured polygon.

This next note isn't a requirement, but describes a very common instance:
Often, the EM ports exist on the right and left (vertical) walls of the EM analysis box.
What's commonly done is to draw a thin vertical strip of metal that occupies approximately two
grid squares wide, and draw the strip along the left/right box wall, extending the entire way
from top box edge to bottom box edge.  (This strip of metal exists on the next metal layer below
the EM port layer, with dielectric in between).

The text above mentions drawing the "strips" on the next metal layer BELOW merely out of
convention, since that's how it's done in the vast majority of instances.  The approach should
also work if the metal strip is placed on the next metal layer ABOVE as well.

Empower warnings or problems can seem complex at first, but often
have very simple solutions.  Read the Empower documentation within
Genesys HELP, and also there is an excellent application note I often
recommend at  http://www.eagleware.com/pdf/apps/0011_EmpowerGrid.pdf

If you have looked through the HELP items and you're still stuck,
don't struggle to the point of frustration;  send the workspace file
to support@eagleware.com with a description of what you're trying
to do and what's happening.  We'll gladly review it & offer comments.
(If you send email, please also be sure to state what hardware key
you're using and what version software you're using [available in
Genesys from main menu HELP, ABOUT...]  and also state the operating
system on your computer)  

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