CST Studio Suite® gives customers access to multiple electromagnetic (EM) simulation solvers which use methods such as the finite element method () the finite integration technique (FIT), and the transmission line matrix method (TLM). These represent the most powerful general purpose solvers for high frequency simulation tasks. Additional solvers for specialist applications such as electrically large or highly resonant structures complement the general purpose solvers. Alongside these are simulation methods for low frequency, charged particle, electronics, and multiphysics problems.

The seamless integration of the solvers into one user interface in CST Studio Suite enables the easy selection of the most appropriate simulation method for a given problem class, delivering improved simulation performance and unprecedented simulation reliability through cross-verification.

The Asymptotic Solver is a ray tracing solver which is efficient for extremely large structures where a full-wave solver is unnecessary. The Asymptotic Solver is based on the Shooting Bouncing Ray method, an extension to physical optics, and is capable of tackling simulations with an electric size of many thousands of wavelengths.

- Electrically very large structures
- Installed performance of antennas
- Scattering analysis

- Can calculate results farfields, monstatic and bistatic scattering cross sections, sinograms and range profiles
- Supports complex surface impedance, coated materials and thin panel materials
- Curved hybrid surface meshing allows easy, accurate and efficient modeling of complex structures
- Near-field scattering analysis with field probes
- Multithreading, hardware acceleration and distributed computing supported
- Parameter sweeps and optimization

Hybrid field simulation using near-field and farfield sources with the time domain solver, frequency domain solver and integral equation solver

**Eigenmode**

The Eigenmode Solver is a 3D solver for simulating resonant structures, incorporating Advanced Krylov Subspace method (AKS), and the Jacobi-Davidson method (JDM). Common applications of the Eigenmode Solver are highly-resonant filter structures, high-Q particle accelerator cavities, and slow wave structures such as travelling wave tubes. The Eigenmode Solver supports sensitivity analysis, allowing the detuning effect of structural deformation to be calculated directly.

- Filters
- Cavities
- Metamaterials and periodic structures

- Can calculate the eigenfrequencies of a structure and the fields at each mode
- PERFECT BOUNDARY APPROXIMATION (PBA)®, CST’s proprietary meshing technique, allows complex surfaces to be meshed easily, accurately and efficiently
- Automatic creation of dispersion diagrams
- Multithreading and distributed computing supported.
- Parameter sweeps and optimization

- Multiphysics simulation with thermal and mechanical solvers in CST MPHYSICS® STUDIO
- Particle behavior simulation with CST PARTICLE STUDIO®

Filter Designer 2D (FD2D) is a planar filter synthesis tool based on well-respected and mature software from Nuhertz Technologies. FD2D contains a database with a wide variety of filter types, including both lumped element and distributed element implementations. Users input the specifications of the filter – including both the frequency response and any physical limitations, such as the maximum size of the filter and the properties of the substrate – and Filter Designer 2D will automatically suggest a design. With a single button click, fully parametric models of this design can be created for either circuit simulation or full-wave 3D simulation.

- Planar filters
- Circuit filters

- Synthesises a wide range of filter types and topologies:
- PERFECT BOUNDARY APPROXIMATION (PBA)®, CST’s proprietary meshing technique, allows complex surfaces to be meshed easily, accurately and efficiently
- Bessel, Butterworth, Chebyshev I and II, elliptic
- Distributed element, lumped element, active, switched capacitor, digital
- Automatic export of parameterized distributed element, lumped element and active filters to CST DESIGN STUDIO™
- Construction of parameterized planar distributed element filters in 3D for full system simulation

- Circuit simulation with CST DESIGN STUDIO™
- Full wave 3D simulation with the Transient and Frequency Domain Solvers

Filter Designer 3D (FD3D) is a synthesis tool for designing cross-coupled bandpass filters. CoupleFil simplifies the design process substantially by automatically calculating the necessary coupling matrix and suggesting filter topologies that match the user’s requirements. These requirements can include multiple pass-bands and arbitrary transmission and reflection zeroes. Once CoupleFil has synthesized a filter, it can generate a 3D model of the design which can be used as the basis of a full-wave simulation.

- Cross-coupled cavity filters

- Synthesises filters according to specifications, including pass-bands, transmission and reflection zeroes, and group delay.
- Suggests multiple filter topologies.
- Exports fully-parameterized 3D model for further simulation.

- Full wave 3D simulation with the Transient and Frequency Domain Solvers
- Hybrid EM/thermal simulation with CST MPHYSICS® STUDIO

The Frequency Domain Solver is a powerful multi-purpose 3D full-wave solver, based on the finite element method (FEM), that offers excellent simulation performance for many types of component. Because the Frequency Domain Solver calculates all ports at the same time, it is also a very efficient way to simulate large multi-port systems such as connectors and arrays. The Frequency Domain Solver includes a model-order reduction (MOR) feature which can speed up the simulation of resonant structures such as filters.

- General high-frequency applications using small-to-medium sized models
- Resonant structures
- Multi-port systems
- 3D electronics

- FEM implementation
- Can calculate results including S-parameters, surface currents, 3D nearfields and farfields
- Curved tetrahedral meshing, with CST’s propriatary True Geometry Adaption, allows easy, accurate and efficient modeling of complex structures
- Wide variety of material types, including lossy metals, plasma, ferrites and frequency dependent materials.
- Unit cell boundary conditions with Floquet mode ports for simulating arrays
- Multithreading and distributed computing supported.
- Parameter sweeps and optimization
- MOR implementation
- Can calculate S-parameters and 3D nearfields
- Very fast for resonant structures such as filters
- Parameter sweeps and optimization

- Hybrid field simulation using near-field sources with the time domain solver, integral equation solver and asymptotic solver
- Circuit simulation with “Combine Results” in CST DESIGN STUDIO
- Multiphysics simulation with the thermal and mechanical solvers in CST MPHYSICS® STUDIO

The Integral Equation Solver is a 3D full-wave solver, based on the method of moments (MOM) technique with multilevel fast multipole method (MLFMM). The Integral Equation Solver uses a surface integral technique, which makes it much more efficient than full volume methods when simulating large models with lots of empty space. The Integral Equation Solver includes a characteristic mode analysis (CMA) feature which calculates the modes supported by a structure.

- High-frequency applications using electrically large models
- Installed performance
- Characteristic mode analysis

- FEM implementation
- Can calculate results including S-parameters, surface currents, 3D nearfields and farfields
- Curved hybrid surface meshing allows easy, accurate and efficient modeling of complex structures
- Real ground plane
- Multithreading, hardware acceleration, distributed computing and MPI cluster computing supported.
- Parameter sweeps and optimization

- Hybrid field simulation using near-field sources with the time domain solver, frequency domain solver and asymptotic solver

The Multilayer Solver is a 3D full-wave solver, based on the method of moments (MOM) technique. The Multilayer Solver uses a surface integral technique and is optimized for simulating planar microwave structures. The Multilayer Solver includes a characteristic mode analysis (CMA) feature which calculates the modes supported by a structure.

- MMIC
- Feeding networks
- Planar antennas

- Can calculate results including S-parameters, surface currents, 3D nearfields and farfields
- Curved hybrid surface meshing allows easy, accurate and efficient modeling of complex structures
- Multithreading, hardware acceleration, distributed computing and MPI cluster computing supported.
- Parameter sweeps and optimization

- Hybrid field simulation using near-field sources with the time domain solver, frequency domain solver and asymptotic solver

The Time Domain Solver is a powerful and versatile multi-purpose 3D full-wave solver, with both finite integration technique (FIT) and transmission line matrix (TLM) implementations included in a single package. The Time Domain Solver can perform broadband simulations in a single run. Support for hardware acceleration and MPI cluster computing also makes the solver suitable for extremely large, complex and detail-rich simulations.

- General high-frequency applications using medium-to-large models
- Transient effects
- 3D electronics

**FIT implementation**

- Can calculate S-parameters, voltages, currents, 3D nearfields and farfields
- PERFECT BOUNDARY APPROXIMATION (PBA)® and THIN SHEET TECHNIQUE (TST)™, CST’s proprietary meshing techniques, allow complex surfaces to be meshed easily, accurately and efficiently
- Wide variety of material types, including lossy metals, plasma, ferrites, frequency dependent materials and non-linear materials
- Multithreading, hardware acceleration, distributed computing and MPI cluster computing supported.
- Parameter sweeps and optimization

**TLM implementation**

- Can calculate S-parameters, voltages, currents, 3D nearfields and farfields
- Conformal octree meshing can reduce mesh counts by over 99% for significant simulation acceleration
- Compact models allow easy modeling of details such as seams, air vents and thin panels.
- Multithreading, hardware acceleration and distributed computing supported
- Parameter sweeps and optimization

- Hybrid field simulation using near-field sources with the frequency domain solver, integral equation solver and asymptotic solver
- True transient EM/circuit co-simulation with CST DESIGN STUDIO™
- Multiphysics simulation with the thermal and mechanical solvers in CST MPHYSICS® STUDIO
- Cable harness simulation with CST CABLE STUDIO®

A 3D solver for simulating static electric fields.

The Stationary Current Field Solver is a 3D solver for simulating the flow of DC currents through a device, especially with lossy components. This solver can be used to characterize the electrical properties of a component that is DC or in which eddy currents and transient effects are irrelevant.

- High-power equipment
- Electrical machines
- PCB power distribution network

- Can calculate the current flow distribution and power loss on a structure
- Curved tetrahedral meshing allows complex structures to be meshed efficiently
- Automatic creation of dispersion diagrams
- Multithreading and distributed computing supported.
- Parameter sweeps and optimization

- Multiphysics simulation with thermal and mechanical solvers in CST MPHYSICS® STUDIO
- Calculation of secondary magnetic quantities such as inductance and force with Magnetostatic Solver

The Magnetostatic Solver is a 3D solver for simulating static magnetic fields. This solver is most useful for simulating magnets, sensors, and for simulating electrical machines such as motors and generators in cases where transient effects and eddy currents are not critical.

- Sensors
- Electrical machines
- Particle beam focusing magnets

- Can calculate the magnetic field, flux density and resulting forces on a structure
- Curved tetrahedral meshing allows complex structures to be meshed efficiently
- Bessel, Butterworth, Chebyshev I and II, elliptic
- Multithreading and distributed computing supported.
- Parameter sweeps and optimization

- Multiphysics simulation with mechanical solvers in CST MPHYSICS® STUDIO
- Particle behavior simulation with CST PARTICLE STUDIO®

The Low-Frequency Frequency Domain Solver is a 3D solver for simulating the time-harmonic behavior in low frequency systems, and includes magneto-quasistatic (MQS), electro-quasistatic (EQS) and fullwave implementations. This solver is most useful for simulations that involve frequency-domain effects such as skin depth, proximity and dispersive materials.

- Sensors and non-destructive testing (NDT)
- Wireless power transfer and inductive components
- Power engineering components

- Tetrahedral meshing with curved and higher-order elements
- Adaptive time stepping
- Moving mesh – rotational and linear
- Parameter sweeps and optimization

The Low-Frequency Time Domain Solver is a 2D/3D solver for simulating the transient behavior in low frequency systems, and includes both magneto-quasistatic (MQS) and electro-quasistatic (EQS) implementations. The MQS solver is suitable for problems involving eddy currents, non-linear effects and linear/rotational motion. The EQS solver is suitable for resistive-capacitive problems.

- Electrical machines and transformers
- Electromechanical – motors, generators, magnetic gears, actuators
- Power engineering components

- Tetrahedral meshing with curved and higher-order elements
- Adaptive time stepping
- Moving mesh (rotational and linear) for electrical machine simulation
- Core losses
- Can calculate forces and torque
- Parameter sweeps and optimization

CST Studio Suite® gives customers access to multiple electromagnetic (EM) simulation solvers which use methods such as the finite element method (FEM) the finite integration technique (FIT), and the transmission line matrix method (TLM). These represent the most powerful general purpose solvers for high frequency simulation tasks. Additional solvers for specialist applications such as electrically large or highly resonant structures complement the general purpose solvers. Alongside these are simulation methods for low frequency, charged particle, electronics, and multiphysics problems.

The seamless integration of the solvers into one user interface in CST Studio Suite enables the easy selection of the most appropriate simulation method for a given problem class, delivering improved simulation performance and unprecedented simulation reliability through cross-verification.

The Particle-in-Cell (PIC) Solver is the most versatile solver in CST PARTICLE STUDIO®. The PIC Solver is a self-consistent simulation method for particle tracking that calculates both particle trajectory and electromagnetic fields in the time-domain, taking into account the space charge effects and mutual coupling between the two. This allows it to be used to simulate a huge variety of devices where the interaction between particles and high-frequency fields are important, as well as high-power devices where electron multipacting is a risk.

- Accelerator components
- Slow-wave devices
- Multipaction

- Can calculate the eigenfrequencies of a structure and the fields at each mode
- PERFECT BOUNDARY APPROXIMATION (PBA)®, CST’s proprietary meshing technique, allows complex surfaces to be meshed easily, accurately and efficiently
- Automatic creation of dispersion diagrams
- Multithreading, GPU hardware acceleration and distributed computing supported.
- Parameter sweeps and optimization

- Multiphysics simulation with thermal and mechanical solvers in CST MPHYSICS® STUDIO
- Particle behavior simulation with CST PARTICLE STUDIO®

The Particle Tracking Solver is a 3D solver for simulating particle trajectories through electromagnetic fields. The space charge effect on the electric field can be taken into account by the Gun Iteration option. Several emission models including fixed, space charge limited, thermionic and field emission are available, and secondary electron emissions can be simulated.

- Particle sources
- Focusing and beam steering magnets
- Accelerator components

- Calculates particle trajectories, beam current, emittance, perveance and collision information
- Gun iteration for space charge effect
- Secondary electron emission materials including Furman and Vaughan models
- Parameter sweeps and optimization

- Static fields from Electrostatic Solver and Magnetostatic Solver
- Field import from Eigenmode Solver

The Wakefield Solver calculates the fields around a particle beam and the wakefields produced through interactions with discontinuities. The structure is excited by a line current – with longitudinally Gaussian shaped charge distribution – representing the beam.

- Cavities
- Collimators
- Beam position monitors

- Calculates transient field distribution, beam frequency, wake potential, kick factor, impedance, and loss factors.
- Dispersive and lossy metal material properties allow the evaluation of resistive wall wakefields.
- Multithreading, distributed computing and MPI cluster computing supported.
- Parameter sweeps and optimization