Phased Antenna Array Simulation Approaches in ANSYS HFSS
Hello, this is Ibrahim Nassar with OZEN Engineering. In this demo, I will show you the different methods that can be used to analyze finite phased arrays using ANSYS HFSS. We will be using the ANSYS 2024 R2 release.
Unit Cell Model Setup
We will start this demo with a unit cell model of a simple patch antenna that operates at 30 GHz and is fed by a coaxial feed from the bottom side. This model was created using the antenna toolkit. An air box surrounds the antenna and touches the substrate from all sides. We use lattice pair boundaries to create a patch and model the periodicity of this unit cell. A radiation boundary is applied from the top side.
Methods for Analyzing Phased Arrays
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Explicit Method
The explicit method involves creating a model of an 8x8 array by copying and placing the unit cell geometry. This traditional approach meshes and simulates the entire array together. For larger arrays, this process becomes complex and requires significant computing resources, limiting the ability to simulate much larger arrays.
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Finite Array Domain Decomposition Method (FADDM)
In this method, HFSS creates a mesh of a unit cell and duplicates it across all array elements, reducing meshing time and memory usage. This method reinforces mesh periodicity, improving simulation accuracy.
- Copy the unit cell model and paste it as "Finite Array Domain Decomposition" (FADDM).
- Import the mesh from the unit cell model.
- Use domain decomposition to distribute the mesh and access distributed RAM, allowing for larger arrays with reduced simulation time.
- Create the array by selecting "Create Array" and set it to 8x8 with no padding cells for visibility.
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3D Component Array Method
This method is similar to FADDM but requires the unit cell to be created using 3D components. It offers faster simulation and less memory usage, leveraging distributed computing resources.
- Create a 3D component from the unit cell model.
- Insert an HFSS design named "Component Array DDM" (CADDM).
- Bring in the 3D component and set the solution type to "HFSS with hybrid and arrays."
- Create the array as 8x8 without padding cells, and set all unit cells to active.
- Set up the analysis with advanced options, using domain decomposition and selecting adaptive options for component adaptation.
Simulation Performance
Let's compare the simulation time and memory usage for these methods:
- Explicit Method: Maximum memory: 15.3 GB, Simulation time: 8 minutes.
- FADDM: Maximum memory: 6.48 GB, Simulation time: 1 minute and 38 seconds.
- 3D Component Array Method: Maximum memory: 5.3 GB, Simulation time: similar to FADDM.
For larger arrays with more computing resources, the 3D Component Array Method offers further RAM reduction and faster simulation times.
Additional Features
In this demo, we created a uniform 8x8 array, but there are options to create shaped arrays and modify components:
- In the Component Array DDM Method, control component rotations to create different configurations.
- In FADDM, create shaped arrays by selecting unit cells as padding to form sparse arrays.
- For larger arrays, use a CSV file to speed up the array creation process.
This concludes the demo. Thank you for watching.
Hello, I'm Ibrahim Nassar with OZEN Engineering. In this demo, I will show you different methods for analyzing finite phased arrays using ANSYS HFSS. We will be using the ANSYS 2024 R2 release.
We will start with a unit cell model of a simple patch antenna operating at 30 GHz, fitted with a coaxial feed from the bottom side. This model was created using the antenna toolkit. We created an air box to surround the antenna and touch the substrate from all sides.
We used lattice pair boundaries to create a patch and model its periodicity. From the top side, we used a radiation boundary. The first method we will cover is the explicit method. I have already created a model of an 8 by 8 array by copying and duplicating the unit cell.
This traditional approach involves meshing the entire array, which can be complex for larger arrays and require significant computing resources. The second method is the finite array domain decomposition method (FADDM).
In this method, HFSS creates a mesh of a unit cell and duplicates it to all other array elements, significantly reducing meshing time and memory. This method also reinforces mesh periodicity, improving simulation accuracy. To set up FADDM, copy the unit cell model and paste it as a new model.
Instead of free meshing the unit cells, import the mesh from the unit cell model. Go to the variable mapping tab and map the variables by name. Ignore all mesh operations in the target design. Reduce the maximum number of passes to one and select the domain decomposition solver.
In the FADDM method, create the array by right-clicking on the model and selecting "create array." Set the array size to 8 by 8, and select the vector for each direction. Set padding cells to 0 to make it identical to the explicit method.
The third method is the 3D model, or 3D component array method. This method utilizes efficient domain decomposition and enables faster simulation and lower memory usage compared to FADDM.
It also allows the user to insert different 3D component unit cells, modeling finite semi-periodic structures with non-identical unit cells for increased flexibility. To set up the 3D component array method, create a 3D component of the unit cell.
Then, insert an HFSS design and bring in the 3D component. Change the solution type to HFSS with hybrid and arrays. Create the array as before, and select the unit cell tab to choose which components are active or passive. Now, let's compare the simulation times and memory usage for these methods.
The explicit approach takes 8 minutes and 15.3 GB of RAM. The FADDM method takes 1 minute and 38 seconds with 6.48 GB of RAM, a reduction of about 2.3x. The component array DDM method takes 1 minute and 5.3 GB of RAM, a further reduction of about 1.2x.
In summary, we have covered three methods for analyzing finite phased arrays using ANSYS HFSS: the explicit method, FADDM, and the 3D component array method. Each method has its advantages and trade-offs, and the best choice depends on the specific requirements of your project.
Thank you for watching.
