Re: [SI-LIST] : May 9th Presentation: "Radiation from Edge Effects in Printe...

About this list Date view Thread view Subject view Author view

From: sweir (weirsp@atdial.net)
Date: Tue May 09 2000 - 11:31:46 PDT


Didn't that open the circuit at the source and prevent the stub from radiating?
At 09:08 AM 5/9/00 -0400, you wrote:
> >
> > Chris R.:
> >
> > One exemplary case I recently came across had a series-terminated clock
> line
> > that was immediately submerged to a stripline which went to a connector on
> > the edge of a PCB. The optional card that would use the connector was NOT
> > installed. The connector receptacle pin rose above the PCB about 3/16
> inch.
> > This small 3/16-inch stub coupled harmonic energy to the SURFACE of the
> PCB
> > (a ground plane) at the SURFACE resonant frequency of the PCB. Surface
> > currents could be measured all over the surface ground plane (with a small
> > Fischer Communications probe). NASTY radiation resulted.
> >
> > Simple removal of the series termination resistor at the clock driver end
> > reduced system radiation over 30 dB.
>-----------------------------------------
>How do you explain this significant reduction in emission levels by
>the simple removal of the series termination resistor?
>-----------------------------------------
>
> > Mike
> >
> > Michael L. Conn
> > Owner/Principal Consultant
> > Mikon Consulting
> >
> > *** Serving Your Needs with Technical Excellence ***
> >
> > **** To unsubscribe from si-list or si-list-digest: send e-mail to
> > majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE
> > si-list or UNSUBSCRIBE si-list-digest, for more help, put HELP.
> > si-list archives are accessible at http://www.qsl.net/wb6tpu
> > ****
> >
> >
>
>**** To unsubscribe from si-list or si-list-digest: send e-mail to
>majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE
>si-list or UNSUBSCRIBE si-list-digest, for more help, put HELP.
>si-list archives are accessible at http://www.qsl.net/wb6tpu
>****

**** To unsubscribe from si-list or si-list-digest: send e-mail to
majordomo@silab.eng.sun.com. In the BODY of message put: UNSUBSCRIBE
si-list or UNSUBSCRIBE si-list-digest, for more help, put HELP.
si-list archives are accessible at http://www.qsl.net/wb6tpu
****


About this list Date view Thread view Subject view Author view

This archive was generated by hypermail 2b29 : Wed Nov 22 2000 - 10:50:14 PST