The Cyber-Spy.Com Usenet Archive Feeds Directly
From The Open And Publicly Available Newsgroup
This Group And Thousands Of Others Are Available
On Most IS NNTP News Servers On Port 119.
Cyber-Spy.Com Is NOT Responsible For Any Topic,
Opinions Or Content Posted To This Or Any Other
Newsgroup. This Web Archive Of The Newsgroup And
Posts Are For Informational Purposes Only.
Reply-To: "Kevin Aylward"
From: "Kevin Aylward"
References: <3DC1D056.email@example.com> <3DC1F17C.D3149AB3@SpamMeSenseless.us.ibm.com> <3DC21367.7060908@BOGUS.earthlink.net>
Subject: Re: Who thinks this?
X-Newsreader: Microsoft Outlook Express 6.00.2800.1106
X-Inktomi-Trace: public1-pete2-5-cust19.pete.broadband.ntl.com 1036138005 24108 18.104.22.168 (1 Nov 2002 08:06:45 GMT)
Date: Fri, 1 Nov 2002 08:06:44 -0000
NNTP-Posting-Date: Fri, 01 Nov 2002 08:06:46 GMT
"Chris Carlen" wrote in message
> Phil Hobbs wrote:
> > I'll leave the LC transmission line questions to others, and just
> > an observation about really fast interconnections: At very high
> > (2 Gb/s or higher), transmission lines on circuit boards really do
> > like distributed RC circuits, e.g. they slow down quadratically with
> > distance. The reason is basically copper losses and dielectric
> > absorption in common materials such as FR4 board. To get fast
> > to go any distance on a backplane, you have to do all sorts of ugly
> > preemphasis tricks to preserve bandwidth. In many instances, e.g.
> > IBM Regatta servers, fast logic signals are demultiplexed down into
> > several lines each to cross the board or backplane, then multiplexed
> > back up into the original logic line. Ugly but necessary--this
> > your dad's computer.
> > One reason computer companies (such as my employer) are looking at
> > optical interconnections is that the bandwidth can be preserved over
> > much longer distances.
> Interesting. That indicates a case that is far from ideal, unlike
> I am conjecturing about.
> I'd like to master the totally general simulation of transmission line
> wave propagation, using the transfer function the whole way through.
> But at this point I only know how to do steady state AC, and
> propagation with real reflection coefficients and Zo.
> There's a lot to learn to really understand this subject. It's really
> case where if the mathematical tools aren't available,
Well, that's not really true. Spice3/XSpice has a generic RCLG
transmission line. You can simulate anything you want in time or the
SuperSpice, a very affordable Mixed-Mode
Windows Simulator with Schematic Capture,
Waveform Display, FFT's and Filter Design.
Go Back To The Cyber-Spy.Com
Usenet Web Archive Index Of
The sci.electronics.design Newsgroup