Create a new CST Studio Suite project file. In connected mode the project is created directly; in offline mode a VBA script is returned for manual execution.

Open an existing CST Studio Suite project. In connected mode the project is opened in the running instance; in offline mode a reference is stored for subsequent operations.

Save the currently open CST project. Optionally provide a new path to 'Save As'.

Close the currently open CST project and release its resources.

Get information about the currently open CST project, including connection mode, project path, and status.

List items in the CST project navigation tree. Optionally specify a subtree path such as 'Components', 'Materials', 'Ports', 'Monitors', or 'Results'.

Export the current CST project or its geometry to another format such as STL, STEP, IGES, SAT, OBJ, or NASTRAN.

Get the current CST Studio connection status, including mode (connected/offline), CST availability, version, and work directory.

Create a rectangular brick (box) in CST Studio.

Create a cylinder in CST Studio. Use inner_radius=0 for a solid cylinder.

Create a cone or truncated cone in CST Studio.

Create a sphere in CST Studio.

Create a torus in CST Studio.

Extrude a 2D polygon profile into a 3D solid in CST Studio.

Create a lofted solid between two or more 2D profiles in CST Studio.

Create a bondwire / wire between two points in CST Studio.

Create a 3D polygon curve in CST Studio.

Create a parametric analytical curve in CST Studio using expressions of parameter t.

Create a planar face from one or more closed curves in CST Studio.

Create an elliptical cylinder in CST Studio.

Create a polygon and extrude it along an axis in CST Studio. Convenience tool combining polygon profile creation and extrusion.

Unite/add two solids together. The result replaces solid1 with the combined volume of both shapes.

Subtract solid2 from solid1. The overlapping volume of solid2 is removed from solid1. Solid2 is deleted.

Intersect two solids. Only the overlapping volume is kept, replacing solid1. Solid2 is deleted.

Insert solid2 into solid1. Solid2 is embedded within solid1, maintaining both material regions at the overlap.

Translate (move) a solid by a displacement vector (dx, dy, dz). Optionally create a translated copy.

Rotate a solid by a given angle around an axis (x, y, or z). An optional center point can be specified.

Mirror a solid across a plane (xy, xz, or yz). An optional center point can be specified.

Scale a solid by independent factors along each axis. An optional center point can be specified.

Create a new material with electromagnetic properties in CST Studio. Specify relative permittivity (epsilon), relative permeability (mu), electric and magnetic loss tangents, and conductivity.

Create a lossy metal material in CST Studio. Lossy metals model finite conductivity skin-effect losses, essential for accurate loss calculations in connectors, waveguides, and PCB traces.

Create an anisotropic material with per-axis permittivity, permeability, and loss tangent values. Used for crystals, metamaterials, and composite substrates.

Load a material from the CST material library by its library name. The material is added to the project under the given name.

List available materials from the bundled material database. Optionally filter by category: 'metals', 'dielectrics', or 'substrates'. Returns name, key EM properties, and usage notes for each material.

Assign a material to an existing solid in CST Studio. The solid is specified as 'Component:SolidName'.

Get electromagnetic properties of a material from the bundled database. Returns epsilon_r, mu_r, conductivity, loss tangent, and usage notes.

Delete a material from the current CST project.

Create a frequency-dependent dielectric material using the Debye relaxation model. Models polar dielectrics where permittivity decreases with frequency: eps(w) = eps_inf + delta_eps/(1 + jw*tau). Used for biological tissues, water, polymers, and soil.

Create a Lorentz oscillator dispersive material. Models resonant dielectric behaviour near absorption bands: eps(w) = eps_inf + delta_eps * w0^2 / (w0^2 - w^2 + jgammaw). Used for glass, crystals, and optical materials.

Create a Drude metal model material for plasmonic and metamaterial simulations. Models free-electron metals: eps(w) = 1 - wp^2 / (w^2 + jgammaw). Used for gold, silver, aluminium in optical/THz frequency ranges.

Create a ferrite material with gyrotropic permeability tensor (Polder model). Essential for circulators, isolators, and phase shifters. The Polder tensor describes the anisotropic magnetic response of a magnetised ferrite (Pozar Ch. 9.1).

Create a material with temperature-dependent electromagnetic properties. Specify base properties and temperature coefficients for thermal-electromagnetic co-simulation.

Create a Cole-Cole dispersive material. Generalisation of the Debye model with a distribution parameter alpha (0-1) that broadens the relaxation spectrum. Used for biological tissues, soil, and broadband absorbers.

List available ferrite materials from the bundled database. Returns name, permittivity, saturation magnetisation, linewidth, loss tangent, maximum frequency, and usage notes for each ferrite.

Add a waveguide port for S-parameter excitation. Defines a port face on the boundary of the simulation domain for guided-wave excitation. IMPORTANT: The port plane should be at or near the edge of the model geometry. Ground planes and substrates must NOT extend past the port plane in the port's orientation direction, or VBA execution may hang. For microstrip feeds: place the port at the end of the feed line where the ground/substrate terminates. Use Coordinates='Free' for ports not aligned to the bounding box. Valid orientations: xmin/xmax/ymin/ymax/zmin/zmax.

Add a discrete (lumped) port between two points. Used for circuit-level excitation with a defined impedance.

Add a lumped R, L, C, or RLC element between two points. Value is in ohms for R, henries for L, farads for C.

Add a plane wave excitation source. Defines an incident plane wave with given direction and polarization for scattering / RCS analysis.

Add a Floquet port for periodic structures such as frequency selective surfaces, metamaterials, and phased arrays.

List all ports defined in the current CST project. Returns VBA to query port information, or a description in offline mode.

Delete a port by its port number.

Add a waveguide port with multiple mode monitoring for higher-order mode analysis. Used for multimode waveguides, mode converters, and structures where higher-order propagating modes need to be captured.

Set boundary conditions for the simulation domain. Each face of the bounding box can be assigned an independent boundary type (open, electric, magnetic, periodic, etc.).

Set the background material properties of the simulation domain. The background fills all space not occupied by defined solids.

Set symmetry planes to reduce computation time. Each axis can be assigned electric or magnetic symmetry, or none. Requires the model geometry and excitation to be compatible with the chosen symmetry.

Set the simulation frequency range in GHz. This determines the bandwidth over which the solver computes results.

Configure periodic boundary conditions with optional phase shift for unit cell simulation. Sets X and Y boundaries to periodic and configures the phase shift for infinite array, FSS, and metasurface analysis.

Configure advanced Floquet port settings for periodic structures. Controls the number of Floquet modes and scan angle for phased array element simulation and oblique incidence analysis.

Set the mesh type for the simulation. Hexahedral is used for time-domain, Tetrahedral for frequency-domain, Surface for integral-equation, and Hexahedral TLM for TLM solver.

Set global mesh density parameters controlling automatic mesh generation. Higher cells_per_wavelength gives finer mesh and better accuracy at the cost of longer simulation time.

Add local mesh refinement to a specific solid. This creates finer mesh around critical geometry features like feed points, gaps, or thin layers.

Configure adaptive mesh refinement. When enabled, the solver runs multiple passes, refining the mesh in regions of high field gradient until the result converges within the specified threshold.

Get current mesh statistics and settings. In connected mode this queries the live mesh data; in offline mode it returns the VBA to retrieve mesh info.

Extract mesh quality metrics including total cells, aspect ratios, and cells per wavelength. In connected mode this queries actual mesh statistics; in offline mode it describes what metrics would be returned.

Configure PML (Perfectly Matched Layer) absorbing boundary properties. Controls the number of absorbing layers and the target reflection level for fine-tuning radiation boundary accuracy.

Add a fixed mesh point at specific coordinates for precise field sampling. Ensures the mesh contains a node exactly at the specified location for accurate field probing.

Configure the time domain (transient) solver. This is CST's flagship solver for broadband simulations — it excites the structure with a pulse and computes S-parameters, fields, and farfield across the entire frequency range in a single run.

Configure the frequency domain solver. Best for narrowband problems, resonant structures, and when field distributions at specific frequencies are needed. Supports interpolated, discrete, and general-purpose sweep types.

Configure the eigenmode solver. Computes resonant frequencies and field distributions of cavity structures. Used for filter design, resonator characterization, and Q-factor extraction.

Configure the integral equation (IE) solver. Best for electrically large, open-boundary problems like antenna placement on vehicles, RCS computation, and EMC/EMI analysis where volume meshing would be impractical.

Get current solver configuration and status. In connected mode this queries the active solver settings; in offline mode it describes expected parameters.

Advanced eigenmode solver configuration for higher-order modes. Use this for waveguide mode analysis, cavity resonator design, and filter characterization where fine control over mode count, frequency targeting, and solver order is needed.

Advanced Integral Equation solver configuration for electrically large structures. Provides control over preconditioner, MLFMM acceleration, and low-frequency stabilization for installed antenna performance and large-platform RCS analysis.

Configure the solver for planar multilayer structures. Optimised for antenna-on-PCB, frequency selective surfaces (FSS), and radome analysis using the frequency domain solver with multilayer-specific settings.

Start a CST simulation with the current solver settings. This is a blocking call that waits for the simulation to complete. Use cst_run_simulation_async for long-running simulations.

Start a CST simulation asynchronously (non-blocking). The simulation launches and control returns immediately. Use cst_get_simulation_status to monitor progress.

Check the status and progress of a running CST simulation. Returns information such as whether a simulation is running, progress percentage, mesh cell count, and current time step.

Pause a currently running CST simulation. The simulation can be resumed later with cst_resume_simulation.

Resume a previously paused CST simulation. Use after cst_pause_simulation to continue from where it stopped.

Stop and abort a running CST simulation. Unlike pause, a stopped simulation cannot be resumed — it must be restarted from the beginning.

Extract S-parameter results from a completed CST simulation. Returns S-parameter data (magnitude, phase, real/imaginary) for the specified port pair. In connected mode reads directly from the result tree; in offline mode returns VBA scripts and explains the CST result tree structure.

Get far-field radiation pattern results from a completed CST simulation at a specific frequency. Returns gain, directivity, radiation efficiency, and beam widths. Requires a farfield monitor at the specified frequency.

Add a field monitor at a specific frequency to the CST project. Field monitors must be defined before running a simulation to capture field distributions, far-field patterns, surface currents, or power flow at the desired frequency.

Get input impedance (Z-parameters) for a port from a completed CST simulation. Returns real and imaginary impedance vs frequency. Useful for matching network design and feed optimization.

Get Voltage Standing Wave Ratio (VSWR) for a port from a completed CST simulation. VSWR indicates impedance matching quality: 1.0 is perfect match, <2.0 is generally acceptable. Can also be computed from S11: VSWR = (1+|S11|)/(1-|S11|).

Get antenna gain at a specific frequency from a completed CST simulation. Returns peak gain in dBi and the direction (theta, phi) of maximum gain. Requires a farfield monitor at the specified frequency.

Get antenna radiation efficiency from a completed CST simulation at a specific frequency. Returns total efficiency (including mismatch), radiation efficiency (excluding mismatch), and mismatch loss in dB.

List all available results in the CST result tree. Optionally specify a subtree path to narrow the listing. Useful for discovering what simulation results are available before extracting specific data.

Export a simulation result to a file (CSV, Touchstone, or text). Specify the result tree path and desired output format. Useful for post-processing results in external tools like MATLAB or Python.

Get a summary of all key simulation results from a completed CST simulation. Returns an overview of S-parameters, gain, efficiency, and impedance. Useful for a quick design evaluation without querying each result type individually.

Extract S-parameter phase response from a completed CST simulation. Returns the phase of the specified S-parameter vs frequency. Optionally unwraps the phase to remove 360-degree discontinuities. Useful for group delay analysis and phase-matching designs.

Compute group delay from S-parameter phase for a port pair. Group delay is defined as tau = -d(phase)/d(2pif) and represents the signal propagation delay through the device. Useful for UWB antenna and filter characterization.

Extract an E-plane, H-plane, or custom radiation pattern cut from a completed CST simulation at a specific frequency. Returns gain vs angle for the selected plane. Requires a farfield monitor at the specified frequency.

Extract cross-polarization level and cross-polarization discrimination (XPD) from a completed CST simulation. Supports Ludwig-3, Ludwig-2, and circular polarization definitions. Requires a farfield monitor at the specified frequency.

Extract axial ratio for circularly polarized antennas from a completed CST simulation. Axial ratio (AR) indicates the quality of circular polarization: AR=0 dB is perfect CP, AR<3 dB is acceptable. Can plot AR vs angle or vs frequency.

Extract surface current density distribution from a completed CST simulation at a specific frequency. Useful for understanding current flow on antenna structures and identifying hot spots. Requires a surface current monitor at the specified frequency.

Get a detailed efficiency breakdown with loss budget from a completed CST simulation. Returns radiation efficiency, total efficiency, and individual loss contributions (mismatch, conductor, dielectric). Useful for identifying dominant loss mechanisms in antenna designs.

Extract time-domain port signal waveforms from a completed CST time-domain simulation. Returns incident, reflected, or transmitted signal vs time. Useful for UWB pulse analysis, time-domain reflectometry, and transient response evaluation.

Extract Smith chart formatted impedance data from a completed CST simulation. Computes normalized impedance from S11 reflection coefficient: Z = Z0*(1+S11)/(1-S11). Returns real and imaginary parts of the normalized impedance for Smith chart plotting.

Calculate impedance bandwidth from S-parameter results. Finds the frequency range where S11 (or VSWR) meets the specified threshold. Returns center frequency, bandwidth in MHz, and fractional bandwidth percentage.