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Old 03-06-2018, 11:50 AM
paulears paulears is offline
Join Date: Oct 2015
Location: Lowestoft - UK
Posts: 351

I thought we had answered it?

There is very little information on these devices, but I think we should assume the resistance measurement is radiation resistance, rather then something very simple like DC resistance. Radiation resistance for a simple antenna like a wave vertical on a ground plane should read about 72Ohms. The analyser just uses the results of the sweep to implement the maths required. At resonance, the impedance is mostly resistive - so your impedance measurement indicates the impedance pretty accurately. At resonance, the reactive component should be 0 Ohms - but this would also mean that it wouldn't actually be much use as an antenna as the energy injected wouldn't be going anywhere.

So I suppose the aim is for VSWR to be 1:1, Impedance to be 50 Ohms, radiation resistance 72 Ohms and reactance 0. These will be mutually impossible to get, each having impact on the others.

If you have a 50Ohm dummy load, run this past your analyser. Then try to make all the results you get fit and produce conclusions. Sometimes weird results will make sense, once you figure out what is happening.
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