[SI-LIST] : Dual Stripline impedance

Magnus Homann (homann@erv.ericsson.se)
Wed, 15 Apr 1998 16:45:26 +0200

Hi all,

We're thinking about using a dual stripline for a differential
pair. The diff. impedance should be 100ohm.

Have anyone used this before? Or seen it in suggested? Come to think
of it, it does sound like a good idea (not mine). Now, the hard part
is getting the right geometry... Any help from various programs or
books? Any references would very helpful, the only one I found is in
"Transmission Line Design Handbook", and it is not very clear. Can you
analyze this with a field solver?

The concept goes like this (cut-through view of the board):

Plane
-----------------------


--------
| L1 |
--------

--------
| L2 |
--------


-----------------------
Plane

The Zdiff should be between L1 and L2.

Homann