[SI-LIST] Re: (no subject)
- From: Glen Walpert <gwalpert@xxxxxxxxxx>
- To: si-list@xxxxxxxxxxxxx
- Date: Wed, 11 Dec 2002 18:32:32 -0500
I am no expert on this, but it is my understanding that the edge
compressors used in samplers are based on nonlinear transmission lines,
also called shock lines, where the high amplitude portion of a pulse
propagates faster than the lower amplitude portion (or vice versa to
compress the trailing edge). These devices incorporate varactors in the
transmission line, so that the capacitance per unit length decreases (or
increases) with pulse amplitude, thus increasing (or decreasing)
propogation velocity with increasing amplitude - effectively varying Er
with amplitude, not frequency. An example can be seen at
http://www.picosecond.com/objects/AN-13.pdf
and Google turns up loads of interesting info with a search on "nonlinear
transmission line" including analysis of electrical soliton propogation.
Regards,
Glen
At 02:31 AM 12/12/02 +0800, D G wrote:
>Jim,
>
>This is true, and is used to good effect in sampling technology. However,
>if I'm not mistaken, the sharpening of the rising edge comes at the
>expense of the falling edge, which becomes more "rounded".
>
>- Daniel
>
>From: "Knighten, Jim L" <JK100005@xxxxxxxxxxxxxxxx>
> >
> > Jeff,
> >
> > Here's one for the dead horse:
> >
> > Rounding of edges: If a dispersive medium propagates high frequencies
> > faster than low frequencies, it is quite possible to see edges in a time
> > domain pulse sharpened, rather than rounded (degraded).
> >
> > Jim
> >
> >
> > Jim Knighten, Ph.D.
> > Teradata, a Division of NCR http://www.ncr.com
> > 17095 Via Del Campo
> > San Diego, CA 92127
> > USA
> > Tel: 858-485-2537
> > Fax: 858-485-3788
> > jim.knighten@xxxxxxx
------------------------------------------------------------------
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:
