What is the recommended ratio between mesh cell size and via port diameter when meshing a patch antenna geometry in MATLAB Antenna Toolbox for accurate simulation results?

I am simulating a patch antenna with a via port feed using MATLAB's Antenna Toolbox. When meshing the antenna geometry, I need to understand the correct relationship between the mesh cell size and the via port diameter to ensure accurate simulation results.

Specifically:

- What should be the ratio between the linear mesh cell size and the via port diameter?

- Is there a recommended minimum number of mesh cells across the via diameter?

- Does this ratio affect convergence of S-parameters or radiation patterns more significantly?

Any guidance or references to best practices would be greatly appreciated.

My code is attached

Thank you!

[Victor]

Thank you very nuch for your answer!!!

Answer 1

[Isha]

Hello,

When meshing a patch antenna with a via port feed in MATLAB Antenna Toolbox, there is no fixed documented ratio between mesh cell size and via diameter. Instead, MATLAB guidance emphasizes refining the mesh in regions where current variation is high—especially near the feed/via location Meshing - MATLAB & Simulink.

Mesh size vs via diameter

• MATLAB recommends controlling mesh using wavelength-based criteria (e.g., MaxEdgeLength ≈ λ/10) for overall accuracy.
• For the feed region, finer local resolution is required since excitation occurs there.

Minimum number of mesh cells across via

• MATLAB does not explicitly specify a required number of cells across a via.
• However, sufficient mesh density is required in high-field regions like the feed.
• Recommended to use at least 3 to 4 mesh cells across the via diameter.

Impact on S-parameters vs radiation pattern

• MATLAB documentation shows that feed modeling strongly affects input impedance and S-parameters, with significant differences depending on feed representation. Model Coaxial Gap Feed for Probe-Fed Patch Antenna - MATLAB & Simulink
• S-parameters (e.g., S11) are more sensitive to mesh resolution near the via/feed.
• Radiation patterns are typically less sensitive initially but should be checked after convergence.

Hope this helps.