Applications

EMC /EMI / E3

Electromagnetic Interference (EMI), Electromagnetic Compatibility (EMC) and Electromagnetic Environmental Effects (E3) are very important for systems design and integration.

Electromagnetic Environmental Effects (E3)

Electronic systems may be susceptible to damage Electromagnetic Environmental Effects (E3) that can arise from a variety of natural or man-made environmental sources.  These sources may include Electromagnetic Pulse (EMP), Radio Frequency Interference (RFI), High Intensity Radiated Fields (HIRF), Electromagnetic Interference (EMI), Lightning Strikes, …

E3 applications often involve electrically large structures (aircraft, ships, land vehicles) containing critical details (seams, cables).

Electromagnetic Interference (EMI), Electromagnetic Compatibility (EMC)

Susceptibility, or immunity, aim at ensuring that the system will work in its intended environment without being disturbed.

In terms of modelling, it requires to evaluate the level of signals coupled to cables or to connector pins, or received field strengths. The model can be subjected to both continuous and transitory disturbances.

For EMI, EMC and E3, AxesSim’s simulation technology is ideal for handling these high complexity and electrically large issues

Computational resource requirements scale rapidly as the electrical size of a geometry increases and requirements can easily outstrip available resources for electrically large problems. AxesSim’s simulation environment provides a powerfull set of features for such obstacles:

  • A highly efficient parallel processing FDTD solver allowing the solution of large problems on computers with less main memory than the topic normally requires.
  • A complete set of subcells models (wires, cables, slots, seams, …) that allows to take realistically into account electrical and electromagnetic caracteristics of the sytem with limited constraints on the mesh size ;
  • Dispersive and anisotropic material models (Imperfections in screening material, e.g. skin effect or radiation penetration through walls of finite conductivity, may be taken into account) which combined to subcell models offers the capability to deal with enclosure shielding effectiveness calculation
  • A set of realistic source models plane waves, voltage and current generators, antenna synthetic models, lightning strikes and return conductor systems, …
  • Cable Harness Analysis: complex cable bundles within their operating environment can be solved with Multi-Conductor Transmission Line Theory method (MTL) that is available for cables with arbitrary current return paths.
  • Non-linear transient protection circuits.

 cablesim

 

Biomedical and EM Field Exposure

The interaction of high-power EM fields, even more used in many devices and systems with the human body rises major risks. Waves penetrate the body and deposit energy in the biological tissues, and the resulting heating can cause damage.

Due to the lossy nature of tissues, transmitter design typically focuses on ensuring that sufficient signal is radiated and not lost in the anatomical load, while complying with regulations that limit the specific absorption rate (SAR) and maximum thermal increase in the body.

High-frequency electromagnetic fields (communication systems, mobile communication, wi-fi and radar, …), magnetic fields generated by high currents in applications such as trains and electric vehicles, can pose radiation hazard (RadHaz) problems. Various standards exist to avoid RadHaz issues. As measurement is typically not an option inside the human body, EM simulation is often the only way to analyze the complex field distribution and estimate the resulting hazards.

AxesSim’s simulation environment provides a powerful set of features for such matters:

  • A highly efficient parallel processing FDTD solver allowing the solution of large problems on computers with less main memory than the topic normally requires ;
  • Dispersive and anisotropic material models in volumic and surfacic supports ;
  • A set of realistic source models such as plane wave, voltage and current generators, Near Field antenna synthetic models, …

AxesSim’s tools include a range of post-processing methods for estimating the local and global Specific Absorption Rate (SAR), a standard measurement of energy deposition in the body.

 

Antenna Placement

On systems or devices, antennas are mounted on physical structures which significantly influence their free-space radiation characteristics. Measurements of the radiation characteristics of an antenna mounted on a large platform is difficult, expensive or even impossible to perform. It is important to accurately simulate the interaction of an antenna with electrically large environments in order to be able to predict the radiation characteristics of the installed antenna.

Many proposed solutions  are based upon asymptotic techniques (PO, UTD, GTD, …) that are could be applied in very high frequency when the systems become huge in number of wavelength. Unfortunately many problems of critical antenna installation arise in low and medium frequency bands (HF, VHF and UHF band), in which antenna placement problems cannot be solved by asymptotic technics.

Taking avantage of

  • the highly efficient parallel processing FDTD solver allowing the solution of large problems on computers with less main memory than the topic normally requires,
  • an innovative synthetic antenna model that could be placed on the FDTD mesh system.

AxesSim’s simulation environment provides a powersolution to evaluate installed antenna performances or antenna / antenna discoupling, in a very wide frequency band starting at very low frequency.

Antipodes’ project

 

Cable Coupling

Many electromagnetic issues in systems involve cables.

  • On the one hand cables couple with external electromagnetic fields (radiated from antennas or from external sources) and induce disturbance voltages and currents potentially on equipments electric interfaces. This could lead to a malfunctioning of the system.
  • On the other hand, cables radiate through imperfect shields and cause coupling into other cables, devices or antennas.

In modern systems, cables play an even more dominant role: a modern car has several kilometers of cables (on which some of them flow very intense currents for electric engines for instance), an aircraft has several tenth kilometers of cable, …

It is crucial that early in the design process of complex systems such coupling / radiation / irradiation effects involving cables are taken into account.  From an EMC point of view, it is important to consider the whole definition of the cables of the system due to the fact that induced parasitics could be conducted with low attenuation on the whole cable harnesses.

AxesSim’s simulation technology offers a unique solution for handling these high large cable coupling problems based on a combined FDTD / MTL / Circuit technology. It is an efficient way to solve problems with unrestricted cable paths and a leading solution for the analysis of complex cable problems in time domain.

  • TEMSI-FD is a complete, powerful and versatile FDTD solver (partnership with XLIM)
  • CableSim is a cable harness modeling environment for electromagnetic compatibility (EMC) and electromagnetic interference (EMI) analysis adapted to large network architectures. It allows analysis of complex cable bundles within their operating environment which can be solved with Multi-Conductor Transmission Line Theory method (MTL) in time domain that is available for cables with arbitrary current return paths. CableSim offers the unique capabilty to manage, analyse and simuate the whole cable harnesses of a complex system.
  • A Spice-like circuit solver that allows taking into account Non-linear transient protection circuits.

 cablesim