2022-06-10 02:48 PM
In application note AN4974
Section 7.3 - Verification of the Q factor in the frequency domain (page 40)
Line 4 is a bit ambiguous:
4. "Short" calibration of the coil and conversion to "Z: Reflection"
Can anyone tell me what is being said there a bit more clearly, please? I'm familiar with the open/short/50ohm calibration procedure of the VNA and some aspects of Smith charts. But that line stumps me.
Solved! Go to Solution.
2022-07-26 02:06 AM
Hello Travis,
I also have trouble measuring the Q factor of an antenna with a MiniVNA Pro. In your last message, you provide 2 screenshots for which I would like some precisions :
This last point on S21 is true for both. According to the Agilent E5061A/E5062A ENA Series RF Network Analyzers User’s Guide, Zreflection is a function of Sab (see image below), which is S21 to me.
My question is : did you perform a transmission measure ? How ?
Finally, isn't the measure of Q on time domain with a scope more precise ?
Thanks for your answers,
Nicolas Meunier.
2022-09-25 11:41 PM
Hello Nicolas,
Yes the conversion with the above formula is do able. Anyhow our VNA has a build in conversion function which does the job.
Yes Chapter 7.2 of the above mentioned application note AN4974 guides you, how to calculate the q-factor from rise and fall time between 90% and 5% of the signal.
BR Travis