Hi All,
I help a company get their Data Bus products EMI Compliant; they have an
industrial ethernet to Fibre product that is reasonably robust, and quite low
emissions.
Contact me off line if you need their information.
Cheers,
Derek.
Fred Townsend wrote on 8/30/2006, 3:14 PM:
There are RJ45s with built in ferrite filters but that sounds like a poor band
aid. I also think you will find building wave guides a tad more difficult than
you anticipate. Fortunately I think there are several must better solutions.
Ethernet over fiber has been around for a long time. It may be hard to find and
may have interface problems. (i.e. both ends of the ethernet must be modified
to fiber. Sill a lot easy than building an EM wave guide.
Second, there are IR ethernet extenders. IR will bounce off a plaster wall so I
don't think it would be to hard to get it to propagate a short distance through
a plastic tubing helix screwed into your chamber wall. The helix will
effectively close RF aperture to prevent your noise transfer. I think you will
find it much easier to build optical wave guide rather than EM wave guide.
Fred Townsend
DC to Light
McInturff Gary wrote:
Dumb question maybe
I have to get a UTP Ethernet connection out of a semi-anechoic
chamber. There no anti-chamber so any unfiltered cable routing opening is a
major leak because of the opening and the induced noise on the cable itself.
Since Ethernet signals don’t like to be filtered. I’m considering two options –
neither of them make me real happy.
1) Find, if one exists, some sort of metallic RJ-45 bulkhead transition
connectors and mount that into the transition panel. I’ve seen the plastic
versions for inter-connecting Ethernet cables, but the were neither metallic
nor bulkhead mounted.
2) Make an air dielectric waveguide out of foot or so ½ inch metal pipe and
attach that to the transition panel and route the cable through the “wave
guide” The opening itself even at ½ is larger than 18 GHz upper test frequency,
but the width of the wave guide buys me some attenuation – and I don’t expect
to see much in the way of ambient up that high anyway.
I don’t have an option of putting the test gear into the chamber with the EUT.
The test gear would be a worse problem.
I don’t think this is completely brain dead but don’t see any easier solution,
but this doesn’t address any induced ambient noise on the cable.
Your thoughts?
Thanks
Gary
- ---------------------------------------------------------------- This message
is from the IEEE Product Safety Engineering Society emc-pstc discussion list.
Website: http://www.ieee-pses.org/
To post a message to the list, send your e-mail to [email protected]
Instructions: http://listserv.ieee.org/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html
For help, send mail to the list administrators:
Scott Douglas [email protected] Mike Cantwell [email protected]
For policy questions, send mail to:
Jim Bacher: [email protected] David Heald: [email protected]
All emc-pstc postings are archived and searchable on the web at:
http://www.ieeecommunities.org/emc-p
Text inserted by Platinum 2006:
This message has NOT been classified as spam. If it is unsolicited mail (spam),
click on the following link to reclassify it: It is spam!
<http://127.0.0.1:6083/Panda?ID=pav_114278&SPAM=true>
______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please visit http://www.messagelabs.com/email
______________________________________________________________________
- ---------------------------------------------------------------- This message
is from the IEEE Product Safety Engineering Society emc-pstc discussion list.
Website: http://www.ieee-pses.org/
To post a message to the list, send your e-mail to [email protected]
Instructions: http://listserv.ieee.org/request/user-guide.html
List rules: http://www.ieee-pses.org/listrules.html
For help, send mail to the list administrators:
Scott Douglas [email protected] Mike Cantwell [email protected]
For policy questions, send mail to:
Jim Bacher: [email protected] David Heald: [email protected]
All emc-pstc postings are archived and searchable on the web at:
http://www.ieeecommunities.org/emc-pstc
