Antenna measurment with VNA

[snkhan]

vna and antenna

There are several companies offering antenna measurement solution with VNA only.
this suggest that one port of VNA works as RF-source while other works as power meter /spectrum analyzer.

Can somebody help to explain the function.

 

[FvM]

how vna works

You can measure antenna impedance in 1-port mode as s11 or gain with an additional reference antenna in 2-port mode as s21.

 

[snkhan]

s21 in antenna measurment

You can measure antenna impedance in 1-port mode as s11 or gain with an additional reference antenna in 2-port mode as s21.

Can you send me some references.

In addition what about antenna pattern (see the picture). If its easy to do only with VNA, what are the limitations

 

[FvM]

time gating of vna

I don't have a reference, it's obvious from VNA operation to my opinion. You have to check the VNA dynamic range and source drive level from the specifications, if the achieved SNR gives sufficient measurement accuracy with the respective free space losses.

 

[shahid78]

antenna vna s11

how can we define the dynamic range of VNA ?

 

[Zottiri Kusuta]

how to measure return loss of antenna using vna

There are several companies offering antenna measurement solution with VNA only.
this suggest that one port of VNA works as RF-source while other works as power meter /spectrum analyzer.

Can somebody help to explain the function.

for return loss (S11) it is OK. but for gain, it is not that trustworthy. you need to make this measurement in an anechoic chamber without any multi-reflections, and you should apply time gating (to clear out the effects of reflections, bounce backs).

 

[prafuldeo]

measuring antenna impedance with a vna

VNA is good for measuring S11, S21, impedance and VSWR. For radiation patterns Anaechoic chamber is best. I never tried measuring radiation patterns using VNA. Also VNA methods seems more susceptible to interference.

 

[snkhan]

Dear fellow i found the source
**broken link removed**


Kindly comment on the authenticity of the measurements if performed in anechoic chamber.