Re: [SI-LIST] : Parallel tracks on Flexible PCB without Ground Plane

Aubrey Keith Sparkman ([email protected])
Fri, 02 Jul 1999 10:58:01 -0500

This is a multi-part message in MIME format.
--------------90053B4F58C6FB714F31BC71
Content-Type: multipart/alternative;
boundary="------------CE4232CD0D15356F1669AAD9"

--------------CE4232CD0D15356F1669AAD9
Content-Type: text/plain; charset=us-ascii; x-mac-type="54455854"; x-mac-creator="4D4F5353"
Content-Transfer-Encoding: 7bit

CAI,
I have solved a similar problem using the technique suggested by Steve Weir <[email protected]> in his message dated Thu, 01 Jul 1999 04:33:39. The way to do this in Ansoft's tool would be to re-label YOUR GND leads as GMETAL
and solve for ALL your leads as signals very far from the solver's ground plane. The tool allows you to "Zero" or "ground out" certain leads after it has completed the field solution. Grounding out the GMETAL leads will then
cause the proper transformation of the mutual coupling values to the values you need.

Aubrey Sparkman
SparkRight Solutions

CAI ZhongPing wrote:

> Dear experts,
>
> Sorry to disturb you again. :) The following figure explains the case more clearly:
>
> ________ ________ ________ ________
> |________| |________| |________| |________|
> GND Signal GND Signal
>
> So they are not driven differentially. General tools calculate differential impedance, right? Can just setting the distance to the plane very high get correct result?
>
> Thanks for your help and look forward to your reply.
>
> Cai
>
> **** To unsubscribe from si-list: send e-mail to [email protected]. In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP. si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list ****

--------------CE4232CD0D15356F1669AAD9
Content-Type: text/html; charset=us-ascii
Content-Transfer-Encoding: 7bit

<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
CAI,
I have solved a similar problem using the technique suggested by  Steve Weir <[email protected]>  in his message dated Thu, 01 Jul 1999 04:33:39. The way to do this in Ansoft's tool would be to re-label YOUR GND leads as GMETAL and solve for ALL your leads as signals very far from the solver's ground plane.  The tool allows you to "Zero" or "ground out" certain leads after it has completed the field solution.  Grounding out the GMETAL leads will then cause the proper transformation of the mutual coupling values to the values you need.

Aubrey Sparkman
SparkRight Solutions
 
 

CAI ZhongPing wrote:

Dear experts,

Sorry to disturb you again. :)  The following figure explains the case more clearly:

   ________    ________    ________    ________
  |________|  |________|  |________|  |________|
     GND        Signal       GND        Signal

So they are not driven differentially. General tools calculate differential impedance, right? Can just setting the distance to the plane very high get correct result?

Thanks for your help and look forward to your reply.

Cai

**** To unsubscribe from si-list: send e-mail to [email protected]. In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP.  si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list ****

--------------CE4232CD0D15356F1669AAD9--

--------------90053B4F58C6FB714F31BC71
Content-Type: text/x-vcard; charset=us-ascii;
name="asparky.vcf"
Content-Transfer-Encoding: 7bit
Content-Description: Card for Aubrey Keith Sparkman
Content-Disposition: attachment;
filename="asparky.vcf"

begin:vcard
n:Sparkman;Aubrey
tel;fax:(512) 371-0960
tel;home:(512) 371-0949
tel;work:(512) 699-6609
x-mozilla-html:FALSE
org:SparkRight Solutions
adr:;;4907 Valley Oak Drive;Austin;TX;78731;
version:2.1
email;internet:[email protected]
x-mozilla-cpt:;1
fn:Sparkman, Aubrey
end:vcard

--------------90053B4F58C6FB714F31BC71--

**** To unsubscribe from si-list: send e-mail to [email protected]. In the BODY of message put: UNSUBSCRIBE si-list, for more help, put HELP. si-list archives are accessible at http://www.qsl.net/wb6tpu/si-list ****