labview VNA waveform

[Owen7]

Hi , I am using the ZVL VNA from R&S. I want to change the waveforms of the VNA to check which one suits my experiment best, but I do not know how to use labview to change the waveform in VNA, anyone know how to make it?

[cstorey]

What do you mean by "waveform options".  VNAs supply sinusoidal signals at variable frequency and power, while measuring the reflected and transmitted power at each port.  Comparing the measured to the source power they represent the results as s-parameters.  You can usually specify a frequency or power sweep.  Some VNAs have other options that use the receivers as spectrum analyzers or noise analyzers.  You usually need additional hardware and software for these options. 

You can set sweep frequencies, power levels and other options there is a LabVIEW driver available on the R&S site for the ZVL - https://www.rohde-schwarz.com/sg/driver/zvl/

I'd explore the examples included in the driver to see what is possible.  Also the manual should have all of the SCPI commands for controlling every feature of your VNA. 

[Owen7]

Thanks， cstorey

I have download the drivers,  what the examples that driver shows is to set parameters like starting frequency, center frequency , steps and so on. Those are basic operations which we also can make on the VNA itself.

The signal that ZVL sends out is a linear sweeping signal, the frequency increases with the time, right? When reading some thesis on VNA, I found many people talked about step-frequency signal(as the screenshot I attach), does the VNA send out a step-frequency signal? if so, how long does the signal hold in one frequency step?if not, does it send a signal like chirp, just one point at each frequency?

Is there a possibility that I send out both step-frequency and chirp signal by VNA?

[cstorey]

The frequency sweep of a VNA is usually a step function.  You can control the dwell time of each step, and the number of steps in a sweep.  Also, you can set a specific frequency and dwell indefinitely, then grammatically move to another frequency.  I'm not sure that a VNA can produce a chirp signal.  It might be possible, it might be an option I'm not aware of but I've never heard of it.  I'd call R&S engineering and discuss if its possible with your model.