From: Dan Swanson (email@example.com)
Date: Fri Mar 31 2000 - 04:38:43 PST
I believe a true stripline mode must have equal return currents
in both planes.
You can set up a simple experiment on a field-solver. Build
a microstrip to stripline transition and look at the currents in
the ground planes. With no vias connecting the ground planes,
the currents are clearly not balanced. You also launch a parallel
plate waveguide mode at the transitions.
If you put several gnd vias around the signal via and connect the
two planes together, the ground plane currents are balanced and
the parallel plate mode is greatly reduced.
You have to be carefull how you set this up in some field-solvers,
if you allow currents to flow in the box walls of the simulator, it
can mask some of these effects.
Dan Swanson EMAIL: firstname.lastname@example.org
Bartley R.F. Systems TEL: (978) 241-1091
38 Water Street FAX: (978) 388-7077
Amesbury, MA 01913
From: =?BIG5?B?Sm9obiBMaW4gKKpMtMK31yk=?= [SMTP:John@quantatw.com]
Sent: Thursday, March 30, 2000 8:00 PM
Cc: 'Kai, Francis'
Subject: [SI-LIST] : Return path for stripline, two ground planes or one power and one ground?
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