Remcom's EM Simulation Numerical Methods
Explore the core numerical methods utilized in Remcom’s software products. Remcom’s EM analysis products are used for a wide range of applications, requiring a variety of numerical methods to cover all of your EM challenges, from the simple to the technically complex.
Several EM solvers and ray-tracing techniques work together to ensure a comprehensive design and analysis process, from device design and antenna placement to EM propagation and wireless communication system analysis.
Finite-Difference Time-Domain Method (FDTD)
While many electromagnetic simulation techniques are applied in the frequency-domain, FDTD solves Maxwell’s equations in the time domain. This means that the calculation of the electromagnetic field values progresses at discrete steps in time. One benefit of the time domain approach is that it gives broadband output from a single execution of the program; however, the main reason for using the FDTD approach is the excellent scaling performance of the method as the problem size grows. As the number of unknowns increases, the FDTD approach quickly outpaces other methods in efficiency.
Ray-Tracing Methods
Ray-tracing methods use discrete rays to represent advancing wavefronts as they propagate from a transmitter through a scene. Rays interact with geometry in the scene through reflections, diffractions, and transmissions. The two dominant ray-tracing methods are Shooting-and-Bouncing Rays and Image Theory. Remcom’s software combines these two methods to leverage the advantages of each.
Ray-Tracing with Geometric Optics and UTD
Wireless InSite’s ray-based solvers use Geometric Optics (GO) and the Uniform Theory of Diffraction (UTD) to evaluate a ray path’s electric field. These methods provide accurate results when the scenario geometry is large compared to the wavelength of the propagating wave. For typical applications, the GO/UTD-based models provide accurate predictions from approximately 100 MHz to approximately 100 GHz.
Ray-Tracing with Physical Optics and MEC
The Physical Optics (PO) ray-tracing method involves a full surface integration over faceted structures and is typically used for complex scattering analysis. Effects can be further improved through edge corrections based on techniques such as the Method of Equivalent Currents (MEC). Remcom’s WaveFarer radar simulation software uses these techniques with specialized ray-tracing that ensures full target illumination; additional enhancements account for near-field effects and multipath in order to simulate interactions between a radar and its immediate environment.
XFdtd’s Electrostatic Solver
Remcom’s static solver module is a second-order solver which works with the same geometry and grid used for time-domain computations and is compatible with the time-domain solver. In addition to fully static problems, the solver may be used to compute initial conditions for a time-domain simulation, such as those involving time-varying switches or nonlinear electric or magnetic materials.