Context- I have an N2PK VNA and it works great. It offers 90dB dynamic range which is not bad although I would like to improve that if possible. By comparison the Array Solutions products only offer 60dB. The N2PK myVNA software is excellent. I was thinking about taking the same basic design and extending its frequency range, dynamic range, and accuracy.
Thanks for the ref to Copper Mountain. I had not heard of them.
Looking at the Copper Mountain Planar TR1300/1, it looks pretty good. The spec says 130 dB dynamic range and it runs 300 kHz to 1.3 GHz. Accuracy is reasonable - would be better but the coupler directivity is poor. In fact, I am skeptical that the device can be as accurate as claimed - however, maybe my common sense is fooling me. It provides only 1-path measurement but that it is sufficient for my purposes. I haven't tried their software. The price is $2.5K which is about what an 85047a in good condition would cost.
So... I understand the argument. Maybe trying to build a one-off device, while it might be fun, would be a bit impractical. Thanks for the feedback.
Jim
At 12:25 PM 12/31/2012, you wrote:
On 31 December 2012 15:30, Jim Schatzman
<<mailto:james.schatzman%40futurelabusa.com>james.schatzman@...> wrote:
All-
Hypothetically, would it be plausible to build a VNA with custom synthesizer/detectors and the 85047A test set? There seems to be plenty of room inside the box to add the other components. Also, is the 85047A the best choice, assuming that the desired frequency range is 1 MHz to 4 GHz?
Thanks-
Jim
What would be your idea - create a unit controlled via USB and have a
PC as the interface? Like this sort of thing?
<>
That would seem to me the only way you could fit everything inside the
box, as you are not going to fit a screen on the test set.
The hardware design, testing, software development etc would suggest
to me this would be a very long term project. I think trying to base
it on something pre-existing like the test set might slow developement
more than help.
Designing a VNA for 4.2 GHz is not going to be easy.
Rather you than me!
Dave
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