re: [SI-LIST] : Diff measurements with VNA
fabrizio zanella (firstname.lastname@example.org)
Wed, 25 Feb 98 11:36:15 -0500
how many ports are you trying to measure, two or four? What is your
If you need more than 2 ports, multiport measurements with a VNA is not an
easy task. I had looked into it a few years ago, and at the time you could
only take 2 port measurements with a VNA. None of the manufacturers (HP,
Wiltron) could support multiport measurements with a VNA, so you could only
measure return loss, insertion loss, and coupling between 2 lines.
I do know that a couple of engineers have written software and created
hardware to create a multiport network analyzer, but I believe these were
internal efforts, so you'd have a hard time purchasing an off the shelf
If you only need two ports, to measure differential reflection of the pair,
you will still need to find some software which can take one of the VNA
signals and invert it in phase, to create a differential pair. Any
thoughts on this?
I remember there used to be a newsletter on VNA measurement techniques
called 'MAMA's Notes', I don't recall who published it. I would try your
HP sales rep, ask for application notes and companies they may be working
with that have done this before.
Hope this helps
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From: "Katie Rothstein" <Katie_Rothstein@notes.teradyne.com>, on 2/25/98
If anyone could point me in some direction regarding differential
with a Network Analyzer I would greatly appreciate it. I'm starting from
ground floor here, so thoughts, information, or possible sources would be
helpful! Thank you!