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Can VST measure VSWR or insertion loss?

First of all, I'm not well versed in RF/telecommunications.

 

We have VST, NI PXIe-5644R, and I'm wondering if it can be used to measure VSWR, reflection coefficient or insertion loss.  We are in UHF frequencies and exploring testing capabilities in antenna tuning.

 

I appreciate any insight.

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Hello bwv1043

Those measurements are typically performed by a VNA. Can you elaborate on your application and explain why you need to use a VST to perform those measurements?

Wan L
Applications Engineer
National Instruments
http://www.ni.com/support
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I'm investigating whether we can use VST for this measurement to avoid purchasing VNA.

 

I will be testing a device that has a closed loop system to read back transmitted power and adjust the impedance to optimize output power of antenna.  I need a way to measure VSWR so that we can verify that antenna is being tuned effectively.  From my search, it seems very unlikely that VST can do it out of box but would be curious to know if there is a way to measure something similar to verify whether antenna is being tuned correctly.

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Hello bwv1043,

I do not recommend attempting to build VNA functionality into a VST because significant calibration effort is put into a VNA to achieve the level of performance typically expected from VNA measurements. Theoretically, a combination of sources, analyzers and directional couplers and satisfy the basic architecture of a VNA, but such a system does not warrant the same specifications as an out of the box VNA. The reliability of the measurements taken by the resulting system is the main problem.  This is a complicated issue to address. If you would like to have a more detailed discussion, I highly recommend creating a service request through NI Support to speak with an Applications Engineer.


Wan L
Applications Engineer
National Instruments
http://www.ni.com/support
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It seems less advisable to use VST for VSWR or similar measurements as I get more input here and offline.  Thank you for your insight.

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