Measuring electrical delay from waveguide offset short

[Tuomas Haitto]

Hello,

What is most usefull way to measure electrical delay from waveguide offset short? I performed well 1-port waveguide calibration, but when I'm trying to measure
DUT's offset short electrical delay VNA-Tools II showing it slightly wrong (place where can calculate Agilent, Anritsu, Rohde&Schwarz polynomical values and delays)

- Tuomas

[Tuomas Haitto]

Hello,

Any advices to waveguide offset short measuring? It's important, because when calibrating waveguide calibration kits, waveguide lines (offset) electrical delay is important

to characterize. Depending from manufacturer, but often lines electrical delay is mentioned in spesification.

- Tuomas

 

[Michael Wollensack METAS]

Hi Tuomas,

The tabular page called Cal Std Model Fit in VNA Tools is only for coaxial calibration standards. As well the Database / Calibration Standard / AgilentModelStandard is only for coaxial calibration standards.

The transmission line model is not the same for coaxial as for waveguide, see for example page 9 and 32 - 38 in the application note from Keysight, see http://literature.cdn.keysight.com/litweb/pdf/5989-4840EN.pdf.

Regards

Michael

[Tuomas Haitto]

Hi Michael,

Now I know this and it's good to remember. If I have measured first flush waveguide short and then added between short DUT offset line (for example 1/4 offset). Do I have then any posibility to define
electrical lenght of the offset using VNA-Tools II?

- Tuomas

[Michael Wollensack METAS]

Hi Tuomas,

with the current version of VNA Tools V1.8.2 you can't. I'll add this request to the wishlist.

Regards

Michael

[Tuomas Haitto]

Hello,

That is very good thing and definetly one of the fundamental features if VNA-Tools II wants to use waveguide kits calibrations.

- Tuomas

[Michael Wollensack METAS]

Hi Tuomas,

I've extended the in VNA Tools used Agilent calibration standard model for waveguide.

This will be part of the next release V1.9.x (October 2017).

Regards

Michael

[Tuomas Haitto]

Hello Michael,

That is very good news !! So when I have done waveguide calibration using Keysight kit. I can then measure for example Anritsu offset short and characterize it offet delay in mm ( in second photo)?

- Tuomas
 

[Michael Wollensack METAS]

Hi Tuomas,

yes.

Regards

Michael