Introduction
Satellite internet connectivity is in increasing demand with estimates suggesting a market size of greater than $33 billion by 2030. Diverse applications are supported by Satellite connectivity including maritime, aviation, military and defense, and facilitating communication during disasters and emergencies. It is essential for providing seamless connectivity to areas where wired or wireless infrastructure is unreliable or costly to implement. In addition, it offers global coverage and connects areas with challenging environments like oceans and mountainous regions. Satellite internet communication requires advanced RF antennas to enable efficient broadband and multiband GEO, LEO, and cellular connectivity.
Phased array antennas are essential in satellite communication. Advanced beam steering, beam forming, tracking mobile satellites, and supporting multiple simultaneous communication are all challenging application requirements. Designing these antenna arrays involves complex mathematics that requires accurate and efficient full wave simulation. Ansys HFSS full-field 3D electromagnetic simulation software can simulate a complex 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. This blog illustrates the different approaches with ANSYS HFSS technologies that can be used to efficiently simulate phased antenna arrays.
Figure 1: Illustration of an HFSS simulated antenna array with far field pattern.
Phased Antenna Array Simulation Approaches
ANSYS HFSS offers 3 different approaches for Phased Antenna Array simulation:
1) Unit Cell-Infinite Array
Array factor calculation is a powerful technique to approximate finite array patterns based on a single simulated antenna element. By leveraging this capability, engineers can quickly evaluate array performance, saving time and computational resources. This method simplifies the analysis of antenna arrays by mathematically combining the radiation pattern of a single array element with a user-defined configuration of multiple elements. This approach provides insights into how an antenna array will behave without the need to simulate the entire array physically, which can be computationally expensive.
Figure 2: Illustration of array factor calculation of a Unit Cell antenna
An HFSS single array element solution does not generally consider 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 produces 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) 3D Component Array
The 3D component array (CADDM) method is a breakthrough technology for efficiently simulating complex antenna arrays. In this method, 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. This method utilizes efficient domain decomposition-based finite element technique (DDM) for modeling finite semi-periodic structures which contain non-identical unit cells for increased flexibility. 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. This simulation technique enables faster simulation and less memory usage, and it can leverage distributed computing resources.
Figure 3: FADDM adaptive meshing process.
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 allows any arrangement of those unit cells within the array dimension that user defines.
Figure 4: Comparison of the Different Array analysis approaches.
More information can be found in this link: https://blog.ozeninc.com/resources/phased-antenna-array-simulation-approaches-in-ansys-hfss
Advanced Phased Array Design
Using the CADDM method complex phased array geometries can be efficiently created and analyzed. HFSS 3D modeler integrates a flexible array builder tool that simplifies the process of creating the array geometries. This tool is not limited to uniform arrays; it enables intuitive sparse and shaped array masks generation. These masks can create different configurations like Diamond, Circular, Oval, and more, each with unique geometric patterns.
Figure 5: Illustration of sparse and shaped array masks.
The CADDM method also enables efficient simulation of periodic and semi-periodic array configuration. The unit cell structures used to build the array do not have to be identical. They can be in different shapes, sizes, and internal geometry. However, the unit cells must be defined as 3D components and the dimensions of the unit cell bounding box must be identical. Using this method, multi component arrays can also be defined combining different types of antenna elements, and enabling multiband and dual polarization to achieve nowadays satellite communication requirements.
Figure 6: multi component arrays can combining 2 different types of antenna elements.
Full Array System
The antenna array system design involves the development of beamforming circuits to control the characteristics of the radiated beam. ANSYS HFSS designs can be dynamically linked into ANSYS Circuit to accelerate the design process and increase the design flow, power, and flexibility of the full array system including the beamforming network. With the dynamic link between HFSS and Circuit, the user can include active components, circuit components, S parameter data to accurately model the feeding network. After the feeding network is designed, the user can then easily characterize the impact on the radiation performance and view the final beam characteristics in HFSS.
Figure 7: A full array system example with the dynamic link between HFSS and Circuit.
Antenna Array on Platform
ANSYS HFSS enables the integration of the full array system on large platforms providing antenna designers with the ability to simulate large-scale antenna arrays and other complex structures while placed on it is actual platform and environment. This enables accurate modeling of the array installed performance. Using the hybrid solve technique, HFSS leverage the advanced solving technologies including integral equation (IE) and shooting and bouncing rays (SBR+) techniques to efficiently model Antenna arrays on electrically large platforms. This approach is not limited to single array placement, multiple arrays which are enclosed by Finite Element Boundary Integral (FEBI) boxes can be simulated.
Figure 8: An example of installed antenna array on a large platform.
Modeling the antenna array enclosure and radome is a crucial part in the process of modern array system development. Inside the radome, there might be also a need to integrate impedance surfaces, matching layers, and polarizers to meet the high-performance requirement for satellite communication. With the CADDM method, the antenna array enclosure and other layers can be included in the array model to improve the simulation efficiency.
Figure 9: Example of a defined antenna array enclosure.
Beam Steering
ANSYS HFSS provides different solution types and tools to enhance the beam steering analysis. Using the network analysis solution type, HFSS solves for arbitrary phase and amplitude of the excitation sources and provides the ability for the user to modify the excitation after the simulation is completed as a post processing step. This allows the user to apply different amplitude and phase weighting and characterize the beam. Changing the excitations as a post processing step requires recalculations of the fields and this can add significant simulation time for very large arrays with large count of excitations. In 2025 R2, an enhancement has been made to accelerate the array beam steering analysis. With this enhancement, the user can save excitation weightings, and the fields will be saved during the solve process. This enables faster beam-steering analysis with up to 17X faster processing.
For large arrays, the user can also significantly speed up the simulation by selecting the composite excitation solution type. With composite excitation, the user needs to provide a complete set of excitations in the sources definition before starting the simulation. This method also reduces significantly the needed RAM allowing the user to solve much larger antenna arrays.
Figure 10: Example of large array beam steering analysis
HFSS also includes The Finite Array Beam Angle Calculator Toolkit. This toolkit provides a comprehensive interface for calculating phase shifts along the A and B vectors of an array lattice, based on the scan angles for array elements. It also offers a script template for users to reference when adding functionality and automation to their projects. Additionally, the toolkit includes post-processing variables for driven and design variables, allowing users to adjust parameters outside the calculator interface and view the results. The toolkit supports different types of tapering, such as triangular, cosine, and hamming window, which can be applied to each individual source either as an equation or a calculated value. Users can choose to calculate taper weights in various coordinate systems and visualize the results in a color map.
Figure 11: Finite array beam angle calculator interface
High Performance Computing
High performance computing (HPC) is a key enabler for large scale antenna array system simulation. HPC significantly maximizes simulation value, enabling users to increase the number of design iterations for study of larger and more complex antenna array models at faster speeds.
There are several HPC technologies that can maximize HFSS simulation speeds and capacity. Matrix multi-processing, for example, uses multiple CPU cores to solve dense frontal matrices allowing the solution process to speed up through parallelization and distribute the memory.
In addition to CPU matrix multi-processing, users can leverage a graphics processing unit (GPU) for more HFSS solver speed. The GPU works in conjunction with CPUs to provide a larger speedup factor. With the HFSS distributed memory matrix solver (DMM), more memory and more cores on networked machines can be accessed, enabling the solve of much larger problems. However, using distributed memory in no way compromises the accuracy of the solution. HFSS with DMM solves a fully coupled electromagnetic system matrix at scale.
Figure 12: Automated hierarchical High-Performance Computing
Summary
ANSYS HFSS provides different solving techniques for the accurate and efficient simulation of advanced antenna arrays for satellite communication. The CADDM allows for fast simulation of complex, electrically large antenna arrays without compromising accuracy. Using the hybrid solve technique, the array performance can be simulated in the realistic platform environment. With the dynamic link between HFSS and circuit, the full system can be simulated, and the development process can be accelerated.