Learning Forum

[Tarun Maddipatla]

Hello, 

I am trying to simulate a microstrip line in Ansys HFSS. However, after setting the solution setup, I am facing an error in the software. It is stating "Setup1: Mesh Sze (1518540 volume elements) exceeded Ansys Electronics Desktop Student Limit" and next it is stopping the execution. 

I have tried reducing the dimensions of the microstrip line. However, it was of no use. Could anyone help me resolve the mesh limit error. I need this for my final year project. It is really important. I have attached the error faced. I have also tried reducing the mesh to a coarser level and simulating it. But it showed the error again. Later I have tried reducing the maximum number of elements and maximum length of elements under length based mesh refinement. Then the elements reduced from 1518540 to 1420417. But even then it is exceeding the mesh limit.

Can anyone help me resolve this issue? Is there any way to alter the mesh limit? Or how can i further reduce the mesh size in my simulation?

[VJ]

Try reducing the mesh size. The student version of HFSS supports up to 64,0000 3D Volume elements.

Check the Product Restrictions tab - https://www.ansys.com/academic/students/ansys-electronics-desktop-student

[Tarun Maddipatla]

Yes I have tried reducing the mesh size. Could you please give me the steps for reducing the mesh size properly in the software. I have already tried reducing the mesh size using the Length based mesh refinement. I am new to this software. Hence, I am finding it a lot diffcult to reduce the mesh size.

[Aymen]

The mesh size of your design exeeds by far the limitations of the HFSS student version. You need to use the commercial version if available to solve this project or try Ansys Cloud https://www.ansys.com/products/cloud/ansys-cloud

[Praneeth]

 

Hi Tarun,

As VJ mentioned, the Ansys student version supports only up to 64,000 3D elements.

However, with this limit, you should be able to solve your microstrip line model if it is a simplified model. Please provide the following details to help us serve you better-

1. Solution setup
2. Model objects and the implementation of the top and bottom conductors
3. Initial and any other mesh settings 

Kindly go through this informative video on this subject – Simulation of a Microstrip Line in Ansys HFSS.

Best regards,
Praneeth.

 

[Tarun Maddipatla]

1. Solution Setup - Modal
2. Top and bottom conudcters - given perfect E field excitation. The microstrip and the layer below the substrate are not assigned any material. They are simple rectangle objects
3. Mesh settings haven't been provided any. I am simulating the above micrsotrip line at 60GHz frequency. My laptop has 4 cores and 4GB RAM.
4. The substrate is made of SiO2 (er = 4) and width of the microstrip line (top layer) is 5.0989045mm. Please check these details and help me fix this issue

[Praneeth]

Hi Tarun,

Did you mean that you are using the Perfect E boundary for top and bottom conductors? You can assign the top and bottom conductors as 2D sheets instead of 3D boxes for optimizing the model.

May I know the length of the transmission line along the X-axis?

If you are using a straight section of the transmission line then you can reduce its length by a significant factor and still be able to do the required analysis using the deembed option of the waveport. Please go through the "differential microstrip" example available under the "open examples" (HFSS>Transmission Lines).

Best regards,
Praneeth.

[Tarun Maddipatla]

Yes I have assigned perfect E boundary to ground plate and the metal plate above. The length of the microstrip line along Y-axis is 10mm and along X-axis is 5mm. The width of the metal line above the silicon dioxide substrate is 5.09mm. Height of the substrate is 4mm.

Now, I am getting the error "SOLVER_OUT_OF_MEMORY" error. Ihave tried reducing the number of passes from 6 to 2. But even then I am getting the above memory error

[Praneeth]

Please share the screenshots of the whole profile window to help us serve you better. It looks like your computer resources are not enough to run the simulation.