At 08:24 AM 12/28/2006, Richard \(Rick\) Karlquist wrote:
>Anyone interested in this topic should read the
>recent QST article on the AIM-4170 antenna analyzer.
>The article has a shoot out of this unit vs other
>ham units and even an Agilent NA. It is a true
>vector analyzer with a narrowband receiver. Most
>other analyzers are scalar analyzers that use
>the "3 voltmeter method" to determine phase angle
>(which is why they can't determine sign) and use
>a broadband detector, which is susceptable to BC
>interference. The N2PK design is similar, but you
>have to homebrew it, AFAIK.
Actually, the 3 meter method can determine phase, except you need one
more volt meters. That's really the basis of the 6 port network
approach (6 ports: 1 input, 1 output, 4 measurement ports)
However, as Rick points out, broadband detectors have their limitations.
>I have purchased one of these and am evaluating it.
>I will report on it on the reflector after I have
>some experience with it.
>BTW, I work for Agilent and am currently designing a new
>Agilent network analyzer, so I have more than a
>casual interest in these units.
How about one that can do phase measurements to 0.1 degree at 35 GHz
on single 4 ns pulses <grin> with mag(S21) of 0 to -100dB.
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