Learning Forum

[H B]

Hello,

I am trying to reproduce the results of a paper (https://www.mdpi.com/2079-4991/11/8/2108) that simulated a microwave antenna for spin control with nitrogen-vacancy centers (not important).

By keeping to the microstrip simulation tutorial from ansys:

I implemented the geometry in ansys HFSS. Unfortunately, even after setting the excitation voltage to 5V (0.5W as in the paper) the resulting S11 curve:

 

 is missing the most important resonance (2-3 GHz) from the paper:

Is there any obvious reason for the simulation as depicted in the tutorial to not reproduce the behavior of the antenna? Some meshing issues? I tried both using the titanium ground plane as a model, as well as just using the back surface of the glass substrate as a GND plane. The waveguide is simulated as a plane structure with finite conductivity of gold.

 

Thank you for any help!

[GioF]

Hi H B,

The short answer to your question is that there is not an obvious reason which leads to some differencies in the results.

The trend of your model's S11 curve looks close to the one in the paper. Since you can't be sure that you are simulating exactly the same model with the one in the paper (same boundaries, same ports) some differencies in the plots should be expected.

To get closer results for the lower end of the frequencies, I would suggest to do the following:

1) Push the convergence criteria to a lower number and enforce a denser mesh. 

2) Use a discrete frequency sweep with sufficient number of points for the lower end of the Frequency range.