[SI-LIST] Re: Coaxial Cable crosstalk
- From: Scott McMorrow <scott@xxxxxxxxxxxxxxxx>
- To: deibele@xxxxxx, silist <si-list@xxxxxxxxxxxxx>
- Date: Tue, 05 Feb 2002 09:09:42 -0800
Craig,
At Frequencies from DC to 1MHz, you should be concerned, since the skin
depth of copper at 1 MHz is 2.6 mils. Fields penetrate everywhere.
I've run similar types of problems through Ansoft Maxwell Q2D for planar
structures, using non-ideal ground planes, and had results which were
within 1dB of measurements for crosstalk isolation of around 60 dB. I
extracted multisegment lumped models for the structure and simulated
them in HSPICE and extracted the S12 crosstalk values for two traces on
opposite sides of a plane.
This same proceedure should work for your twinax case, as long as the
shields are treated as non-ideal conductors.
regards,
scott
--
Scott McMorrow
Principal Engineer
SiQual, Signal Quality Engineering
18735 SW Boones Ferry Road
Tualatin, OR 97062-3090
(503) 885-1231
http://www.siqual.com
>We have an application where we have twinax (twinax is like coax, except
>it has two conductors surrounded by an outer shield instead of one
>conductor surrounded by an outer shield like coax). The frequency is
>DC-1MHz or so.
>
>These cables are long....separate sources, and they will all be
>collected at a common point where they will share a small space, and
>then separate again.
>
>There is some cables with high currents on them...on the order of a few
>thousand amps....which may/may not have switching supplies driving them.
>
>So, if I have a small signal cable nearby...how can I reliably predict
>what the crosstalk/might be?
>------------------------------------------------------------------
>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 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 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:
