Two port VNA suggestions

[kc0ws]

In another thread Bob asked for suggestions about features to include in a 2-port VNA, so I decided to start a thread for that topic.

Suggestion: Bring out all the "sensor ports". A full-blown VNA (e.g. Agilent) does not have its uses limited by its arrangement of parts. It has a signal source and three vector voltmeters brought out to the front panel. This allows it to be used for many things besides impedance measurements, like antenna range measurements and array element phase measurements.

I feel the TAPR architecture is limited, because they have chosen to bring out only one "out" and one "in". The architecture used by the N2PK dual detector unit with the external bridge seems much more flexible.

BTW, have you seen the March 2009 issue of High Frequency Electronics magazine? The front-page article is titlled "USB Power Sensors + Standard Lab Equipment = Scalar Network Analyzer". I have not had a chance to read it through yet, but it looks very interesting. If they could just add phase detection....

[kc0ws]

Another feature that would make this type of equipment more popular would be some kind of spectrum analyzer capability. I don't know how much complication it would take to use the existing DDS circuitry to drive a direct-conversion spectrum analyzer, but I know that it would interest a lot of users. I just had to haul a PowerAim 120, a TAPR VNA, and a portable spectrum analyzer on an overseas trip to tune up an FM diplexer and do other work on three stations. If that were all in one box it would be quite attractive.

[f6gnz]

Yes, it would be great to have two ports that would allow to test/align filters etc, but for actual owners of the AIM4170 it would be highly desirable to make this feature available as a field add-on kit to their AIM4170...