Reply To: 180 Degree Phase Shift When Measuring S21

[spate035]

Hi David,

Regarding the radiation box, I meant I tried a single radiation box encapsulating both antennas, as well as a separate simulation where I had the two antennas in individual FEBI boundaries.

I am maintaining the distance between the antennas as I rotate. I have tried a short distance... actually the distance between the two spheres (the ones the antennas lie in) is 150mm. As I'm simulating at roughly 10GHz, the antennas are only about 5 wavelengths apart.

Regarding the convergence, I've taken a look, and it seems that the convergence from one adaptive pass to another can jump up by 180 degrees. If you take a look at the below image, at -10degrees, the simulation seems like it will converge near -79degrees, but then at adaptive pass 7 it shoots up by 180.

Convergence shoots up at pass #7, which is again where the change from -79 to 101 occurs as highlighted above, and then it settles back down.

And then if you take a look at the first image again and consider the theta_rot = -7degrees case, the value always remains around 110degrees for all 8 adaptive passes. And the convergence doesn't shoot up as we see in almost every other case.

 

I see that you are not having the same issue as I am from the S-parameter plot you posted. So maybe I need to do something special regarding the mesh? I have not changed anything regarding the meshing from the default settings. I'm not quite sure what you mean by "mesh asembly used and mesh is preserved in the parametric sweep to avoidn numerical noise:". How can we use mesh assembly, and is it available in 2021.R1 version? And how did you "preserve the mesh in the parametric sweep?"

 

Thank you,

Shyam Patel