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CADFEKO
CADFEKO is used to create and mesh the geometry or model mesh, specify the solution settings and calculation requests in a graphical environment.
Cables
Many electromagnetic compatibility and interference problems involve cables that either radiate, are irradiated or cause coupling into other cables, devices or antennas. Use the cable modelling tool and solver to analyse the coupling and radiation.
Cable Shields
A cable shield is a conductive layer that encloses a cable to reduce electromagnetic interference (EMI) and crosstalk to other cables.
Weave Definitions for a Braided Cable Shield
CADFEKO supports two methods to specify the size of the apertures for a braided shield layer.

Welcome
Release Notes
See what's new in the latest release.
Get Started
The Feko Getting Started Guide contains step-by-step instructions on how to get started with Feko.
Examples
The Feko Example Guide contains a collection of examples that teaches you Feko concepts and essentials.
Introduction to Feko
Feko is a comprehensive electromagnetic solver with multiple solution methods that is used for electromagnetic field analyses involving 3D objects of arbitrary shapes.
CADFEKO
CADFEKO is used to create and mesh the geometry or model mesh, specify the solution settings and calculation requests in a graphical environment.
- Introduction to CADFEKO
  Use CADFEKO to configure a solver-ready input file for Solver simulations.
- Quick Tour of the CADFEKO Interface
  View the main elements and terminology in the CADFEKO application window.
- Preferences
  CADFEKO has various default settings that you can configure to customise it to your preference.
- Saving a Model
  Store a CADFEKO model and calculation requests to a .cfx file to reopen later.
- 3D View
  3D views are used to display and interact with the model. You can zoom, rotate and pan around a 3D model using the keyboard, mouse or a combination of both. You can use a 3D mouse, specify a view or select specific parts of a model. Multiple 3D views are supported.
- Model Protection
  Protect a model with a password.
- Model Definitions
  Define the model unit, variables, named points, workplanes and the model extents for the model.
- Constructing Geometry
  Create fully parametric and complex CAD geometry using canonical structures and perform Boolean operations on these.
- Component Library
  The component library contains an extensive list of common components, such as antennas and platforms.
- Groups
  Organise geometry and mesh parts by grouping geometry and mesh in the model tree.
- Repairing Geometry
- Repairing Mesh Parts
  Mesh parts can be manipulated in CADFEKO. Basic mesh editing and fixing capabilities allow triangles to be added, removed and mesh parts to be merged.
- Importing Models into CADFEKO
  Import a CAD (geometry) model or mesh model from a wide range of industry formats into CADFEKO to save time and development costs.
- Exporting Models from CADFEKO
  A CADFEKO model can be exported to a variety of industry standard geometry and mesh formats to be used in other applications.
- Field/Current Data
  Define field or current data using either far field data, near field data, spherical mode data or PCB current data. Use the field/current definition when defining an equivalent source or a receiving antenna.
- Defining Media
  Define a medium with specific material properties, import a predefined medium from the media library or add a medium from your model to the media library.
- Applying Media Settings
  Defined media can be applied to the model in various ways. Some media settings are applied to regions, others on faces and wires. The rules for defining media varies between the different solution methods.
- Periodic Boundary Condition (PBC)
  Use a periodic boundary condition (PBC) to analyse infinite periodic structures. A typical application of PBC is to analyse frequency selective surface (FSS) structures.
- Finite Antenna Arrays
  Create an arbitrary finite antenna array that consists of an array of contributing elements, either with direct feeds for each element or via indirect coupling, and solve with the efficient domain Green's function method (DGFM).
- Windscreen Tools
  Use the windscreen tools to define a curved reference surface constrained by a cloud of points, normals and optional U′V′ parameters. The constrained surface is then used as a reference to create a work surface where windscreen layers and curved parameterised windscreen antenna elements can be created.
- Cables
  Many electromagnetic compatibility and interference problems involve cables that either radiate, are irradiated or cause coupling into other cables, devices or antennas. Use the cable modelling tool and solver to analyse the coupling and radiation.
  - Workflow for Analysing Cables
    The general process is explained for setting up a complete cable analysis.
  - Accessing the Cables Tab on the Ribbon
    Open the Cables tab on the ribbon to access advanced tools related to defining cable harnesses.
  - Harness Description List (KBL) Specification
    Cable harnesses are becoming increasingly complex with innovations in the automotive industry. Import a complex cable harness from a .kbl file using the harness description list (KBL) specification.
  - Cable Types
    A comprehensive range of cable types is supported for cable analysis.
  - Cable Shields
    A cable shield is a conductive layer that encloses a cable to reduce electromagnetic interference (EMI) and crosstalk to other cables.
    - Cable Shield Layer Combinations
      When creating a cable shield, you need to specify the impedance and admittance for each layer. The following combinations are supported when defining the impedance and admittance for a shield layer.
    - Creating a Solid Cable Shield Layer (Schelkunoff)
      Create a single-layered solid shield with a specified material and thickness.
    - Weave Definitions for a Braided Cable Shield
      CADFEKO supports two methods to specify the size of the apertures for a braided shield layer.
    - Creating a Braided Cable Shield Layer (Kley)
      Create a single layer, braided (Kley) cable shield. The relevant braid parameters, weave metal and braid-fixing materials (optional) are specified and the Solver determines the frequency-dependent impedance (Zs + Zt) and admittance (Yt) matrix using the Kley formulation.
    - Creating a Braided Cable Shield Layer (Vance, Tyni or Demoulin)
      Create a single layer, braided (Vance, Tyni, Demoulin) cable shield. For a braided shield layer, the relevant braid parameters and weave metal are specified and the Solver determines the frequency-dependent impedance (Zs + Zt) and admittance (Yt) matrix using the Vance, Tyni or Demoulin formulation.
    - Advanced Settings for a Braided Cable Shield Layer
      Use advanced settings to specify how the weave angle and optical coverage changes when a braided shield is applied to a cable bundle or coaxial cable.
    - Single-Layered Braided Shield Models
      A summary is given of the single-layered braided shield models available in CADFEKO and EDITFEKO.
    - Creating a Cable Shield Layer (Shield Properties)
      Create a cable shield by defining the frequency-dependent surface impedance, transfer impedance and transfer admittance matrix.
    - Creating a Cable Shield Layer (Transfer Capacitance)
      The transfer capacitance shield layer is used with a braided and frequency-dependent impedance definition to represent the transfer admittance matrix of the shield layer.
    - Creating a Double Layered Cable Shield
      A double cable shield consists of two shield layers. CADFEKO supports any combination of the shield types, solid, braided and frequency-dependent for the inner and outer layer of the shield.
  - Defining a Cable Path
    Create a cable path (route) along which cables are installed and specified as a series of straight lines.
  - Defining Cable Connectors
    Create a cable connector at the end terminal of a cable.
  - Defining a Cable Instance
    Create a cable instance consisting of a single cable (for example, ribbon, cable bundle, coaxial cable) with its cable connectors that is routed along a cable path.
  - Defining a Shielded Enclosure
    Define a shielded enclosure that allows the outermost shield signals of different cable paths in a combined MoM/MTL cable harness to be connected to a shielded conductive enclosure defined in the full wave (3D) model.
  - Defining a Schematic Link
    Define a connection(s) between circuit elements (defined in a cable schematic view) and the full wave model.
  - Defining a Cable Harness
    Create a cable harness consisting of a collection of cable instances routed along a cable path with a solution method specified for the outer conductor.
  - Searching for a Cable Instance in the Model
    Use the Find cable tool to locate a cable instance contained in a complex cable harness in the 3D view.
  - Combining Cable Instances
    Convert multiple single conductor cables into a new type of cable after a harness description list is imported.
  - Rearranging Cables in a Cable Harness
    Randomly place all tubes in a cable harness using the Rearrange cross sections tool.
  - Cable Schematic View
    The cable schematic view allows you to add cable ports, complex loads, resistors, capacitors, inductors, external SPICE circuits, general networks (defined using N-port Touchstone files) and probes to a specific cable harness as well as connecting cables to one another.
- Solution Frequency
  For a frequency domain result, the electromagnetic fields and currents are calculated at a single frequency or frequency range. When the finite difference time domain (FDTD) solver is used, the frequency must be specified to convert the native time domain results to the frequency domain.
- Power
  The excitation of an antenna is normally specified as a complex voltage, but it may be useful to specify the total radiated or source power instead. The result is then scaled to yield the desired source power level.
- Ports
  A port is a mathematical representation of where energy can enter (source) or leave a model (sink). Use a port to add sources and discrete loads to a model.
- Sources
  A source is used to excite or illuminate the model and cause current to flow.
- Loads and Non-Radiating Networks
  Complex feed networks can be simplified by including them as a circuit representation using general network blocks.
- Multiple Configurations
  Perform multiple solutions for a single model using multiple configurations. Multiple configurations remove the requirement to create multiple models with different solution requests.
- Requesting Calculations
  Before running the Solver, define the output requests and view in the model tree (Configuration tab).
- Infinite Planes and Half-Spaces
  Use an infinite plane or half-space to model a ground plane efficiently. The number of triangles in the model is reduced as the ground plane is not discretised into triangles.
- Meshing the Geometry / Model Mesh
- Domain Connectivity
  Domain connectivity approach allows meshes of specific parts to be treated as if connected during MoM and MoM/MLFMM solutions in places where the borders of the meshes are close together, even if the mesh vertices on those borders are not coincident.
- Working with CADFEKO Models in EDITFEKO
  A CADFEKO.cfm file can be imported into EDITFEKO to make use of more advanced features available in EDITFEKO and to directly edit the .pre file for more flexible solution configurations.
- Validating the CADFEKO Model
  During the design process, the development of a model can introduce a range of issues that can lead to a non-simulation-ready model. Use the validation toolset to verify that the model is simulation-ready or to search, detect and flag discrepancies.
- Solver Settings
  The default solver used in Feko is the method of moments (MoM) - surface equivalence principle (SEP). A solver is specified per model, per face or per region, and depends on the solver in question.
- Component Launch Options
  Specify the command-line parameters for the Feko components.
- Tools
  CADFEKO has a collection of tools that allows you to quickly validate the model, for example, perform calculations using a calculator, measure distances, measure angles and export images.
- Model Tree Icons
  View the list of icons that may be found in the model tree.
- Details Tree Icons
  View the list of icons that may be found in the details tree.
- Math Functions in CADFEKO
  View the list of supported math functions.
- Files Generated by CADFEKO
  View the files associated and generated by CADFEKO.
- Default Shortcut Keys
  View the default shortcut keys available for CADFEKO for faster and easier operation of CADFEKO.
POSTFEKO
POSTFEKO, the Feko post processor, is used to display the model (configuration and mesh), results on graphs and 3D views.
EDITFEKO
EDITFEKO is used to construct advanced models (both the geometry and solution requirements) using a high-level scripting language which includes loops and conditional statements.
Feko Solution Methods
One of the key features in Feko is that it includes a broad set of unique and hybridised solution methods. Effective use of Feko features requires an understanding of the available methods.
Optimisation in Feko
Feko offers state-of-the-art optimisation engines based on generic algorithm (GA) and other methods, which can be used to automatically optimise the design and determine the optimum solution.
Feko Utilities
The Feko utilities consist of PREFEKO, OPTFEKO, ADAPTFEKO, the Launcher utility, Updater and the crash reporter.
Description of the Output File of Feko
Feko writes all the results to an ASCII output file .out as well as a binary output file .bof for usage by POSTFEKO. Use the .out file to obtain additional information about the solution.
Feko Application Macros
A large collection of application macros are available for CADFEKO and POSTFEKO.
Scripts and Application Programming Interface (API)
CADFEKO and POSTFEKO have a powerful, fast, lightweight scripting language integrated into the application allowing you to create models, get hold of simulation results and model configuration information as well as manipulation of data and automate repetitive tasks.
Appendix
Reference information is provided in the appendix.

Weave Definitions for a Braided Cable Shield

CADFEKO supports two methods to specify the size of the apertures for a braided shield layer.

The optical coverage for a braid indicates how visible the apertures are, where 0% is completely open (no shielding) and 100% is a completely filled (approximating a solid shield). The optical coverage and weave angle are coupled by the fill factor (F) for a braid, which is a quantity between 0 and 1.

Figure 1. Illustration of the braid parameters for a braided shield layer.

The fill factor (F) is calculated from the optical coverage using the following equation:

F = 1 - \sqrt{\frac{100 - O p t i c a l C o v e r a g e}{100}}

where the optical coverage is between 0% and 100%.

The coupled equation for the fill factor from the braid parameters is:

F = \frac{n m d}{2 π D \cos (ψ)}

where D is the mean braid diameter (outer radius of the shield minus half the thickness of the braided layer).

Optical Coverage

For the optical coverage definition, a minimum optical coverage is specified. The minimum optical coverage relates to the largest aperture size or minimum shielding that CADFEKO tries to achieve when optimising the braid for maximum coverage, by varying the weave angle.

Weave Angle

A nominal weave angle and deviation is specified for the weave angle definition. The optical coverage is calculated for the range of weave angles to represent the size of the apertures (using the braid parameters defined for a braided layer).

Note: As the weave angle changes, the shield diameter also changes depending on the weave angle and other braid parameters.