Overview
Phased antenna array systems are used everywhere from defense radar applications to commercial 5G applications. Designing these antenna arrays involves complex mathematics that requires full wave simulation. Ansys HFSS full-field 3D electromagnetic simulation software can simulate a complex phased array antenna system in a reasonable amount of time and with low computation costs while considering the effects of complex excitations, environment (i.e., nearby antennas), and the platform on its performance. This blog illustrates the different approaches that can be used to efficiently simulate phased antenna array. Below is a brief overview of the different simulation approaches and a full demonstration is provided in the video link.
ANSYS HFSS offers 4 different Phased Antenna Array simulation approaches:
1) Unit Cell-Infinite Array
This method is a useful tool for antenna array analysis, however, the analysis can yield incorrect results if used improperly. An HFSS single array element solution does not generally take into account the effects of the element's hypothetical neighbors. It assumes that all elements are identical and the element pattern doesn’t depend on the location in the array, if these impacts are significant then this method will be invalid.
In this method HFSS meshes/simulates a unit cell with primary/secondary or lattice pair boundaries to enforce the infinite periodicity. Once the single element radiation pattern is simulated, HFSS mathematically calculates the array factor and get an approximate finite array pattern ignoring edge effects. More information can be found in the this link: https://blog.ozeninc.com/resources/ansys-hfss-array-analysis-using-the-array-factor-calculation
2) Explicit Finite Array
The explicit finite array simulation approach is the traditional method to analyze the entire array. HFSS meshes/simulates the entire structure and includes edge effects, non-uniform array elements, and any geometric arrangement of elements. For large arrays, the meshing process will be complicated and large computing resources will be needed.
3) Finite Array Domain Decomposition
In this method (FADDM), HFSS meshes/simulates a unit cell and duplicates the mesh to the other array elements (no further adaptive meshing is required). This dramatically reduces the meshing time and memory footprint enabling the simulation of a much bigger arrays on the same hardware. The mesh periodicity reinforces array’s periodicity and thus improves the simulation accuracy. Domain decomposition (DDM) is also implemented to distribute the mesh and access distributed RAM throughout a network. DDM distributes a model’s mesh/solution across several computers by distributing the RAM and solves a model’s full behavior as if run on a single computer
4) 3D Component Array
This method (CADDM) utilizes efficient domain decomposition-based finite element technique for modeling finite semi-periodic structures which contains non-identical unit cells for increased flexibility. Compared to FADDM, unit cells in this method must be defined as 3D components. This simulation technique enables faster simulation and less memory usage compared to simulating the FADDM, and it can leverage distributed computing resources. The overall workflow starts with importing the 3D Components into HFSS representing different unit cells in the model. Then creating the array like creating Finite Array from a unit cell. However, this method lists all the unit cell components and allow any arrangement of those unit cells within the array dimension that user defines.
To utilize the 3D Component Finite Array workflow with non-identical unit cells, the unit cells must meet the following requirements:- Unit cells must be defined as 3D Components
- Dimensions of unit cells’ bounding boxes must be identical
- Appropriate Lattice Pairs and boundary conditions must be defined on surfaces of unit cells
Figure1: Comparison of the Different Array analysis approaches
A complete demonstration is provided in the video link below: