Hello,

The link and pdf are attached for help.

https://innovationspace.ansys.com/forum/forums/topic/how-to-make-a-uniform-magnetic-field-in-hfss-using-magnetic-bias/

Thanks,

Yes, it is possible to perform a transient simulation with an RF AC signal in HFSS (Ansys High-Frequency Structure Simulator). HFSS is a powerful tool for electromagnetic simulation, but transient simulation is more commonly associated with time-domain solvers like Ansys HFSS Transient or other tools like Ansys HFSS SBR+ (Shooting and Bouncing Ray), Ansys EMIT, or even Ansys Maxwell for specific types of transient analysis. Here’s a step-by-step guide to setting up and performing a transient simulation in HFSS:

Step-by-Step Guide to Performing Transient Simulation in HFSS

1. Design Setup

Design your Magnetic Material and Biasing Conditions: Ensure that your magnetic material with the appropriate biasing conditions is correctly modeled in HFSS. This includes defining the material properties and biasing conditions accurately.

2. Choose the Correct Solver

Select the Transient Solver: If you are using the standard HFSS, switch to the HFSS Transient Solver if it is available in your HFSS suite. HFSS Transient allows you to perform time-domain simulations, which is necessary for transient analysis with an RF AC signal.

3. Setup the Excitation

Define the RF AC Signal:

- Go to the `Excitations` menu.

- Define a `Voltage Source` or `Wave Port` that will generate the RF AC signal.

- Specify the signal characteristics, such as frequency, amplitude, and phase. For an AC signal, you will typically use a sinusoidal source.

- Ensure the source is correctly placed in the model, applying to the relevant ports or regions.

4. Transient Simulation Setup

Configure the Transient Simulation:

- Go to the `Solution Setup` menu and select `Add Solution Setup`.

- Choose `Transient` as the solution type.

- Set the simulation duration. This should cover the period of interest for your RF AC signal. The duration should be long enough to observe the transient effects you are interested in.

- Define the time step. The time step should be small enough to capture the details of the signal, typically a fraction of the period of the highest frequency component of your signal.

5. Boundary Conditions

Set Up Boundary Conditions:

- Ensure that you have defined appropriate boundary conditions for your model. For transient simulations, you might need to use absorbing boundaries (like PML or radiation boundaries) to prevent reflections that can affect the simulation accuracy.

6. Mesh Setup

Define the Mesh:

- HFSS requires a suitable mesh to accurately simulate the model. For transient simulations, ensure that the mesh is fine enough to capture the variations in the electromagnetic fields accurately.

- You can use adaptive meshing to refine the mesh based on the field distributions.

7. Run the Simulation

Execute the Simulation:

- After setting up the transient analysis, run the simulation.

- Monitor the convergence and ensure that the simulation runs without errors. This can take some time depending on the complexity of your model and the duration of the simulation.

8. Post-Processing

Analyze the Results:

- After the simulation is complete, use the post-processing tools in HFSS to analyze the results.

- You can visualize the transient response of the fields, examine the voltage and current waveforms, and extract other relevant parameters.

- Use time-domain plots to observe how the fields evolve over time and ensure the results make sense physically.

Tips and Best Practices

Ensure Accuracy in Material Modeling: The accuracy of your results heavily depends on the correct modeling of your magnetic material and biasing conditions.

- Validate with Simplified Models:Before running a full-scale transient simulation, validate your setup with simplified models to ensure that your simulation settings are correct.

- Leverage HFSS Documentation and Support: Utilize HFSS documentation and Ansys support resources for detailed instructions and troubleshooting tips specific to your version of the software.

Performing a transient simulation with an RF AC signal in HFSS is possible and can provide valuable insights into the time-domain behavior of your design. By carefully setting up the excitation, simulation parameters, and boundary conditions, and by utilizing the HFSS Transient Solver, you can effectively analyze the transient response of your magnetic material under different biasing conditions. If you encounter specific issues, consider reaching out to Ansys support for detailed assistance tailored to your simulation needs.

Thanks a lot for your insightful comment Md Bellal Hossain Previously, I changed my solution type to transient but the problem is while doing it, it will automatically delete magnetic biasing and show me an error which I have attached here! So, I can't proceed further.

Thanks to @Smrity Dwivedi as well. I will check this out.

When transitioning to transient simulation in Ansys HFSS, some issues can arise, especially with complex setups involving magnetic biasing. Transient solvers in HFSS have different requirements and limitations compared to frequency domain solvers, and sometimes certain settings or features might not directly translate. The error you're encountering is likely due to this mismatch. Here are some steps you can take to resolve the issue:

Steps to Resolve Transient Simulation Issues in HFSS

1. Verify Magnetic Biasing Compatibility

Ensure that the magnetic biasing settings are compatible with transient simulations. Not all features or settings in HFSS are supported in all solvers.

Check Documentation: Refer to the HFSS documentation to confirm whether the specific magnetic biasing feature you are using is supported in transient simulations.

Simplify Biasing: If possible, try simplifying the magnetic biasing configuration to see if a more basic setup can be translated into the transient domain.

2. Update to the Latest Version

Make sure you are using the latest version of HFSS, as newer versions may have improved compatibility and bug fixes for transient simulations involving complex setups like magnetic biasing.

3. Use Equivalent Circuit Models

In some cases, you might need to represent the magnetic biasing effect using equivalent circuit models or simplified physical models that are more compatible with transient simulations.

4. Step-by-Step Reconfiguration

Reconfigure your simulation setup step-by-step to identify which specific settings or features are causing the issue.

1. Create a Backup: Start by creating a backup of your original project.

2. Initialize a Simple Transient Setup: Set up a simple transient simulation without the magnetic biasing first to ensure that the basic transient solver setup works.

3. Incrementally Add Features: Gradually add the magnetic biasing and other complex features back into the simulation, checking for errors at each step.

5. Error Analysis and Troubleshooting

Analyze the specific error message you are receiving. Often, the error message will provide clues about what is going wrong.

Error Logs: Check the error logs for detailed information about the failure.

Common Errors: Look for common issues such as incompatible material properties, unsupported boundary conditions, or invalid solver settings.

6. Seek Support from Ansys

If you are still unable to resolve the issue, consider seeking support from Ansys. They can provide specific guidance based on the error message and your project setup.

Example Procedure

Here’s an example procedure to set up a transient simulation with magnetic biasing in HFSS:

1. Initial Transient Setup:

- Open your project in HFSS.

- Save a copy of your project.

- Go to `Solution Setup` and select `Add Solution Setup`.

- Choose `Transient` as the solution type.

2. Simplified Magnetic Biasing:

- If the magnetic biasing setup is complex, try simplifying it. For instance, use a basic static magnetic field or a simplified equivalent circuit to represent the biasing effect.

3. Adding Magnetic Biasing:

- Add the magnetic biasing to your simplified transient setup.

- Go to the `Fields` menu and apply the magnetic biasing.

- Ensure that all material properties and boundary conditions are correctly defined for transient analysis.

4. Running the Simulation:

- Check all settings and ensure there are no conflicts or unsupported configurations.

- Run the simulation and monitor for any errors.

5. Analyzing Errors:

- If an error occurs, note the error message and check the HFSS error log for details.

- Refer to the HFSS documentation or Ansys support for guidance on resolving specific errors.

Transitioning to a transient simulation in HFSS with magnetic biasing can be challenging due to the complexities involved. By verifying compatibility, simplifying configurations, incrementally adding features, and analyzing errors, you can identify and resolve the issues. If the problem persists, reaching out to Ansys support can provide the necessary assistance to proceed with your simulation.

Thanks a lot, Smrity Dwivedi That link helps.