[SI-LIST] Re: Return loss measurement - odd result - why?
- From: "Tom Dagostino" <tom@xxxxxxxxxxxxx>
- To: <dotter@xxxxxxxxxxxxx>, <si-list@xxxxxxxxxxxxx>
- Date: Wed, 16 May 2007 16:01:13 -0700
Dotter
You may have a stub, a set of discontinuities or some other structure =
that
sets up a quarter wavelength resonator causing this.
Is your system terminated? Do you have clean launches into the DUT? Do =
you
have other pieces of equipment or structures hanging onto the net you =
are
trying to measure? Are there some high Q elements in the net?
Have you thought of making a simple model of what you are measuring and =
see
if there are any clues in the structure of the actual measurement setup =
that
could contribute to these results you are seeing?
Tom Dagostino
Teraspeed(R) Labs
13610 SW Harness Lane
Beaverton, OR 97008
503-430-1065
tom@xxxxxxxxxxxxx=20
www.teraspeed.com=20
Teraspeed Consulting Group LLC
121 North River Drive
Narragansett, RI 02882
401-284-1827
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] =
On
Behalf Of dotter
Sent: Wednesday, May 16, 2007 3:25 PM
To: si-list@xxxxxxxxxxxxx
Subject: [SI-LIST] Return loss measurement - odd result - why?
Hi,
I've been making return loss measurements of balun coupled ADC input=20
using spectrum analyser with tracking gen and a return loss bridge.
The return loss shows a regular "oscillation" of amplitude vs frequency=20
of about 10dB with an extremely regular period of 100MHz across a=20
bandwidth of about 1GHz.
Is this an artifact? It seems extremely stable and unrelated to any=20
clocks in the circuit.
Any ideas what would cause this?
Apologies if this is too far OT!
Dotter
------------------------------------------------------------------
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 technical documents are available at:
http://www.si-list.net
List archives are viewable at: =20
//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
=20
------------------------------------------------------------------
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 technical documents are available at:
http://www.si-list.net
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:
