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conversion loss clarification for minicircuits zem4300 mixer - RF
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balajisu Post subject: conversion loss clarification for minicircuits
zem4300 mixer Posted: Thu Sep 08, 2005 1:32 pm
Captain
Joined: Wed Jul 06, 2005 5:54 pm Posts: 24 Location: Germantown,MD
hi guys
when i try to measure the conversion loss of minicircuits
zem4300 mixer i see a notch near DC rather than seeing a flat response.
A colleague of mine was confident that zem4300 has a flat response from
DC. From my measurement observation i believe there is a rolloff
of conversion loss near dc.
Can anyone clarify in this part.
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rod Post subject: Posted: Thu Sep 08, 2005 4:51
pm are you doing this measurment with your ac coupled analyzer?
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balajisu Post subject: discussion continuedPosted:
Thu Sep 08, 2005 5:40 pm
Captain
Joined: Wed Jul
06, 2005 5:54 pm Posts: 24 Location: Germantown,MD i measured
the conversion loss using a VNA. ( conversion loss mode/mixer measurement
mode)
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Rod Post subject: Posted: Fri Sep 09,
2005 6:18 pm I guess my point was that when LO=RF the output = dc.
Since your analyzer rolls off below 30Khz or so, you should expect
to see a notch.
Measure the mixer's IF port to ground with an
ohmmeter. If you see a resistance, than you can assume the IF will operate
down to dc.
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balajisu Post subject: thanks
rodPosted: Fri Sep 09, 2005 7:56 pm
Captain
Joined:
Wed Jul 06, 2005 5:54 pm Posts: 24 Location: Germantown,MD
hi rod sorry for misunderstanding ur point.
actual setting was
rf swept from 750-850mhz and lo was maintained at 800mhz..
so
with this setting i observed a notch behaviour near dc i .e rf = lo
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balajisu Post subject: clarify?Posted: Fri Sep
09, 2005 7:59 pm
Captain
Joined: Wed Jul 06, 2005
5:54 pm Posts: 24 Location: Germantown,MD hey rod
could
u clarify on: analyser rolls off 30khz or so..
thanks
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Rod Post subject: Posted: Fri Sep 09, 2005 8:10
pm right, when the LO and RF = 800MHz, the output = 0Hz or DC.
Assuming your are using an 8753 type analyzer, the input cannot
measure DC or anything below 30Khz...depends on your VNA model.
The mixer you are refering to makes for a good phase detector, which
of course has a DC output.
It's time to admit to your co-worker
that he was right....have a nice weekend!
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balajisu
Post subject: thanksPosted: Sun Sep 11, 2005 6:37 pm
Captain
Joined: Wed Jul 06, 2005 5:54 pm Posts: 24 Location: Germantown,MD
thanks a lot Rod.
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Rod Post subject:
Posted: Mon Sep 12, 2005 6:29 pm You're welcome.
Hey, and
don't worry about it. I've been wrong like 18 times today, and it's
not even lunch yet.
Posted
11/12/2012
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