VSim for Electromagnetics

VSim for Electromagnetics LogoFast and powerful conformal FDTD for Electromagnetics for a variety of material types, yielding engineering outputs that can be used for design of electromagnetic devices.



Accurately Predict the Performance of Electromagnetic Devices

VSim for Electromagnetics (VSimEM) is a flexible, multiplatform, high-performance, parallel software tool for electromagnetic simulations. VSimEM uses second-order accuracy algorithms for simulating curved geometric structures. The simulation domain can be open, closed, or periodic. The domain may include wave launchers, or ports, as well as absorbing and reflecting boundaries. Custom materials can be assigned to complex geometries either from imported CAD files, or constructed in the user-friendly front end. The advanced graphics capability displays detailed field data with either a uniform or field-scaled mesh.

VSimEM is an accurate tool that caters to antenna and photonic device design. VSimEM is ideal for measuring radar cross sections (RCS) for any scattering device. VSim also has the capability to simulate high-power antennas in plasma environments, such as ion cyclotron resonance heating (ICRH) antennas.

VSim for Electromagnetics can be used in the design cycle for electromagnetic, electrostatic, and magnetic devices. Compute near-field and far-field radiation patterns in record time by using VSim's Kirchhoff Box algorithm. Simulate radar interactions with the total-field/scattered-field method. Determine signals from ground penetrating radar. Model propagation in photonic crystals and other optical devices, as well as in waveguides. Compute oscillations and Q-factors in resonators and cavities. Data analysis plugins enable computations such as S-parameters and antenna gain. Compute the electrostatic field from multiple biased shapes in the presence of dielectric materials.

Powerful Technology

VSimEM makes use of powerful and fast finite-difference technology and advanced algorithms for handling conformal (non-grid aligned) boundaries, for both metallic and dielectric objects. VSimEM makes use of distributed-memory (MPI) parallelism to enable you to solve any size problem, from small through very large. Whether you run VSim on a laptop, computing cluster, or supercomputer, your simulations will run rapidly using algorithms optimized to run on high performance computing systems.



  • Antenna Design
  • RF Devices
  • SAR Calculations
  • Photonic Devices


VSim is a flexible, multiplatform, software tool for running computationally intensive electromagnetic, electrostatic, and plasma simulations. VSim easily installs and runs on a variety of systems, including Windows, MacOS, and Linux platforms. Switching between 1, 2, and 3 dimensions is simple with VSim. Work easily in the required dimensionality, whether 1D for the basics, 2D to capture transverse effects, or fully 3D to ensure all geometric effects are included. Design your simulation using a laptop and run it there, or run the simulation on a cluster.

Examples Make VSim Easy to Learn and Reduce Time to Product

With its Visual Setup capabilities, the VSimComposer interface enables the user to set up electromagnetics problems quickly and easily. Through the point-and-click interface, the user can select solvers and set boundary conditions. The user can also specify the functional form of incoming waves in both space and time. As with all other VSim simulation packages, both data analysis and visualization functionality are integrated into VSim for Electromagnetics. VSimEM provides 21 ready-made simulation examples for problems such as radiation from an airplane mounted antenna, propagation in a dielectric waveguide, and radar scattering from a metallic object.

At Los Alamos we have several modeling needs for projects I’ve been working on, ranging from calculating far-field antenna patterns to the gain of dielectric traveling-wave tubes. These are complex problems and we were unable to set up accurate models of our problems with the previous numerical tools we were using. After seeing results from Tech-X’s VSim at conferences and talking to several colleagues who were using it for scientific modeling (including highly respected colleagues who work at Tech-X), we decided to try it. We were up and running within a few days and now have been using VSim for most of the past year. We have been very impressed with its broad capabilities and ability to model our specific problems. We are also pleased with its intuitive feel and ease of use. It is a great code and we anticipate using it for all our future needs.

—Bruce Carlsten, Senior R&D Engineer, Los Alamos National Laboratory

Easy to Upgrade

Each VSim package can be used stand-alone or in combination with one or more other specialty VSim packages. Start with VSim for Basic Physics to model classical physics. Then when you are ready to simulate more advanced physics problems, add the VSim package that does what you need. If you want to simulate electromagnetics in the presence of metallic and dielectric shapes, upgrade to VSim for Electromagnetics. To model RF power systems, add VSim for Microwave Devices. When you are ready to design plasma acceleration experiments, VSim for Plasma Acceleration can provide fast solutions. For plasma discharges, VSim for Plasma Discharges is available to simultaneously simulate kinetic and collisional effects in plasma.

Later, as your need for computational power expands, add more compute cores to your license.


Geometry and Materials
  • Arbitary geometries with easy construction of complex structures
  • Choose from a variety of pre-defined material types such as copper and niobium or define custom materials
  • Lossfree and lossy, nonlinear, isotropic and anisotropic dielectrics
  • Second-order dispersive dielectrics
  • Excitation with port modes, discrete elements, discrete face ports, as well as plane waves and elliptical polarization
  • Full field/scattered field
  • Periodic and phase-shifted boundary conditions
  • Perfectly Matched Layer (PML) boundaries
  • Matched Absorbing Layers (MAL) boundaries
  • Embedded boundaries for accurate metallic walls
  • Port boundaries: ingoing and outgoing
  • Dey-Mittra cut-cell algorithm
Data Analysis
  • Fastest and most accurate Far field calculations provided by our unique Kirchhoff Box algorithm
  • Radiated-field calculations--directivity, gain, beam width, side-lobe levels, axial ratio
  • S-parameters: single-ended, differential, de-embedded, renormalized
  • Mode calculations using frequency extraction

Advanced Features

  • Specific absorption rate (SAR) calculations
  • Linear plasma dielectric
  • Easily parameterized geometries for parameter sweeping and optimization
  • Availability of non-proprietary output formats that you control, enabling you to access your data with public domain software, Matlab, or your own favorite tool
  • Ability to work from device examples similar to your own device
  • Powerful post-processing capabilities
  • Economical: Use VSimEM as a standalone simulation tool or add advanced physics features as needed by including other VSim packages
  • Easy learning curve: Build your own simulations using built-in examples as a starting point
  • Scales to solve your largest problems. Accurate parallel decomposition for fast solutions
  • Superior customer support by world-class experts

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Example Simulations Included

These example problems that demonstrate complex geometry, dielectrics, scattering, and advanced analysis are included with VSim for Electromagnetics to jumpstart finding the solution to your problem.

Examples Using Visual Setup

Visual Setup Examples are ready to run and easy to use.  Running a Visual Setup Example and then customizing the settings for your own simulation is the fastest way to learn VSim.

Other EM

Examples Using Text Setup

Code your simulation, then run it.  Text Setup Examples demonstrate how to format a simulation input file using code syntax. If you like the level of control available through designing your simulation using VSim code blocks and Python, use a Text Setup file as the basis for your simulation project.

Other EM





VSim model of EM waves scattering off surfacing submarine
EM Waves Scattering Off of Surfacing Submarine

Wave scattering off of a surfacing submarine demonstrates the near-field capabilities of waves scattering off of a three-dimensional figure with a nearby dielectric.

VSim simulation of patch antenna far field

Patch Antenna Far Field

Calculate the far field radiation pattern for a patch antenna.

VSim 3D model of power absorption in dielectrics with human head in profile

Human Head Profile

Power absorption in dielectrics with complex geometry.

VSim predator drone model
Predator Drone

Far field radiation pattern from a point source on a predator drone demonstrates how antenna performance is affected by the local environment.


VSim simulation of horn antenna far field

Horn Antenna Far Field

Horn antennas are widely used at UHF and microwave frequencies because of their ability to focus a beam as this far field radiation pattern demonstrates.

VSim electrostatic charged spheres simulation

Electrostatic Charged Sphere

Two charged spheres, solved using electrostatics.

VSim simulation of dipole above conducting plane
Advanced Dipole Above Conducting Plane

Excellent verification problem for antenna simulations by comparing the far field patterns with analytic solutions.

VSim 3D model of human head in three quarters view with dipole antenna

Human Head Three Quarters View

A dipole antenna near the ear of a human head displays the complex scattering and absorption of electromagnetic radiation.

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