On a PNA N5225A, I obtain inconsistent result when using the de-embedding procedure "Response/Cal/Fixtures/2 port De-embedding".

I have a WR187 waveguide which I load with two sections of different dielectrics (epsilon 1 and epsilon 2). I do three measurements (dielectric 1 alone, dielectric 2 alone and dielectric 1 and 2 cacaded). I wanted to retrieve the S parameter of dielectric 2 by deembedding the dielectric 1 S parameter form the cascaded S parameter. This does not work (the deembedded S parameter are very different from those measured on diectric 2 only). I obtain a correct result when I perform the demebedding with a mathematical software.

Are thre known bugs with such deembedding procedure on the PNA ?

Thank you in advance for your help

I have a WR187 waveguide which I load with two sections of different dielectrics (epsilon 1 and epsilon 2). I do three measurements (dielectric 1 alone, dielectric 2 alone and dielectric 1 and 2 cacaded). I wanted to retrieve the S parameter of dielectric 2 by deembedding the dielectric 1 S parameter form the cascaded S parameter. This does not work (the deembedded S parameter are very different from those measured on diectric 2 only). I obtain a correct result when I perform the demebedding with a mathematical software.

Are thre known bugs with such deembedding procedure on the PNA ?

Thank you in advance for your help

> On a PNA N5225A, I obtain inconsistent result when using the de-embedding procedure "Response/Cal/Fixtures/2 port De-embedding".

>

> I have a WR187 waveguide which I load with two sections of different dielectrics (epsilon 1 and epsilon 2). I do three measurements (dielectric 1 alone, dielectric 2 alone and dielectric 1 and 2 cacaded). I wanted to retrieve the S parameter of dielectric 2 by deembedding the dielectric 1 S parameter form the cascaded S parameter. This does not work (the deembedded S parameter are very different from those measured on diectric 2 only). I obtain a correct result when I perform the demebedding with a mathematical software.

>

> Are thre known bugs with such deembedding procedure on the PNA ?

>

> Thank you in advance for your help

It would undoubtedly help if you posted the all the relevant Touchstone files and a bit more information.

* Is the waveguide just filled with the dielectrics, and open at the end? Shorted at the end? A load attached to the end?

* Are you measuring S11 or S21?

* Show a sketch of the setup.

* Post the touchstone file of what you measured with dielectric 1

* Post the touchstone file of what you measured with dielectric 2

* Post the touchstone file of what you measured with dielectric 1 and dielectric 2.

* What the PNA indicates the S-parameters of dielectric 2 are.

* What the other software indicates the S-parameters of dielectric 2 are.

* What other software you use?

I know you can get issues with higher order modes propagating in waveguides that are filled with dielectrics, although the fact you are able to deembed outside the PNA properly, suggests that's not the case.

Dave