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Amplitude Match - RF Cafe Forums
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| TomCalver
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Post subject: Amplitude Match
Posted: Tue Oct 17, 2006 8:49 am
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Joined: Fri Sep 29, 2006
11:05 am
Posts: 4 |
Ok guys, here's another one.... I've been
asked to perform a "Amplitude Match" between frequencies
on a batch of 4 coax cable assemblies. What
is Amplitude Matching ? How would you perform this
on a VNA ?
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nubbage |
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Post subject: Amplitude Match
Posted: Tue Oct 17, 2006 10:43 am
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| General |
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Joined: Fri Feb 17, 2006
12:07 pm
Posts: 268
Location: London UK
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I guess it depends to some extent on what is implied
by "assemblies". These could be quite complex, or
just individual lengths with a connector each end.
In the latter case, different cable types will
have different dispersion characteristics of the
loss vs frequency response.
If you set up
a VNA to display S21 across the range of frequencies
asked for, there you have it: compare the curves.
If you have a complex assembly with for example
power splitters, you would have to compare port
A on one with port A for the others, and go on doing
this for the other ports, with all other ports correctly
terminated.
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TomCalver |
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Post subject:
osted: Tue Oct 17, 2006 10:56 am
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Joined: Fri Sep 29, 2006
11:05 am
Posts: 4 |
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Thanks for the reply !
This is a simple coax
assembly with 1 connector on each side.
So I'm looking at a S21 measurement. Take the first
one, measure it and save it to memory and compare
the rest vs. that first one. The difference would
be the amplitude difference with the first being
the baseline.
Format would be Logmag ?
So it looks like I'm looking at an insertion
loss difference between cables at a given frequency
span ?
Thanks
Tom
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IR |
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Post subject:
Posted: Tue Oct 17, 2006 1:28 pm
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| Site Admin |
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Joined: Mon Jun 27, 2005
2:02 pm
Posts: 406
Location: Germany
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Hello,
Yes the format should be Log Mag.
You should measure the S21 for each cable in the
given frequency range and compare the obtained S21
curve vs. the frequency.
_________________
Best regards,
-
IR
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Posted 11/12/2012
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