[SI-LIST] Re: uStrip question - repost
- From: "Tom Dagostino" <tom@xxxxxxxxxxxxx>
- To: <bdempsey85@xxxxxxxxxxx>, <si-list@xxxxxxxxxxxxx>
- Date: Mon, 8 Mar 2004 20:26:48 -0800
What you did not mention in your note may be the problem you are having.
How did you connect your VNA to the test articles? How clean was the
launch? It is easy to get large reflections from poorly designed launches
that will affect S21
Tom Dagostino
Teraspeed Consulting Group LLC
Device Modeling Division
13610 SW Harness Lane
Beaverton, OR 97008
503-430-1065
tom@xxxxxxxxxxxxx <mailto:tom@xxxxxxxxxxxxx>
Teraspeed Consulting Group LLC
2926 SE Yamhill St.
Portland, OR 97214
http://www.teraspeed.com
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx
[mailto:si-list-bounce@xxxxxxxxxxxxx]On Behalf Of Bill Dempsey
Sent: Monday, March 08, 2004 7:57 PM
To: bdempsey85@xxxxxxxxxxx; si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] uStrip question - repost
--sorry for the repost but the server is adding junk to the message that
made it unclear to read --
I recently built 3 different uStrip construction testboards and was
surprised by the results: it didn't work!
I built two boards as trace over copper with soldermask and one board
as a co-planar waveguide. I constructed the geometries of the boards by
following the results of some "freebie" tools out there.
After the boards were built I connected them to an HP network analyzer
(I calibrated out the cables/cons) to look at S21 response. What I
found was surprising. The S21 was extremely poor: approx 6.5dB loss
over 4". This just does not compare to the results of the tools I have
access to. I expected about 1.2 - 1.5 dB of loss at this frequency.
Has anyone else out there had some bad experiences with uStrip @
2.5GHz? What tools are you using? How are you correlating your
tool's results to real-world?
The construction of the three boards was as follows:
Board 1: 12 mil trace, 1/2 oz foil with 1 oz plating, 8 mil to gnd (three
sheets of 1080 prepreg), 1oz copper gnd
Board 2: (CPW): 8 mil trace, 8 mils to gnd (again, 3 sheets of 1080
prepreg), 6 mil to gnd return on signal layer, same plating/thicknesses
Board 3: 4.75 mil trace, ~2.83 mils to gnd (one sheet of 1080 prepreg),
1/2 oz foil, 1oz plating, 1oz copper gnd
Regards,
Bill
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List technical documents are available at:
http://www.si-list.org
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
------------------------------------------------------------------
To unsubscribe from si-list:
si-list-request@xxxxxxxxxxxxx with 'unsubscribe' in the Subject field
or to administer your membership from a web page, go to:
//www.freelists.org/webpage/si-list
For help:
si-list-request@xxxxxxxxxxxxx with 'help' in the Subject field
List technical documents are available at:
http://www.si-list.org
List archives are viewable at:
//www.freelists.org/archives/si-list
or at our remote archives:
http://groups.yahoo.com/group/si-list/messages
Old (prior to June 6, 2001) list archives are viewable at:
http://www.qsl.net/wb6tpu
Other related posts:
