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CPW Calculation - RF Cafe Forums
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ljoseph
Post subject: CPW Calculation Posted: Wed Sep 19, 2007 9:16
pm
Captain
Joined: Tue Sep 04, 2007 7:54 am
Posts:
13
Location: Dallas
Hello
With the following parameters,
I am getting different answers with different tools.
H = 0.3mm
Er = 4.25
W = 0.56mm
T= 32.5um
gap = 0.35mm
Freq
1842 Mhz
With this Agilent Appcad gives 50.2 ohms. AWR Tx line
gives 47 ohms.
Following online calculator gives 78 ohms.
http://www1.sphere.ne.jp/i-lab/ilab/tool/cpw_e.htm
Don't understand the reason for this difference.
Top
Jeanalmira
Post subject: Posted: Tue Sep 25, 2007 3:01
am
General
Joined: Tue Mar 15, 2005 11:43 pm
Posts:
65
Location: Singapore
Hi ljoseph,
the difference is
the ground plane.
I believe that for your first calculation (AppCad
and AWR) you included the groundplane (CPW ground)
While the online
calculator is without ground plane.
you can double check the
setting thru AppCad and also AWR (CPW and CPW ground).
Hope
it helps.
Regards,
Jean
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imodelit_moderator
Post subject: Posted: Tue Oct 16, 2007 5:40 am
Captain
Joined: Wed Jun 20, 2007 3:01 am
Posts: 22
Dear ljoseph,
I'm with Jeanalmira in his opinion. As for the lower impedance
values you used -most probably- Grounded-Coplanar. While the larger
values is for the conventional coplanar waveguide -without lower ground
plane-.
Kindly check this online applet, it is for conventional
coplanar waveguide.
http://imodelit.com/ViewDetails.aspx?AID=190
Thanks.
Best Regards,
imodelit Moderator
Posted 11/12/2012
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