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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.
Optimisation Using .PRE File modifications
Use optimisation with modifications made in the .pre file in EDITFEKO.

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.
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.
- Optimisation Workflow in CADFEKO
  The workflow for setting up an optimisation in CADFEKO is explained.
- Launching OPTFEKO (Windows)
  Use the most suitable option for launching OPTFEKO.
- Launching OPTFEKO (Linux)
  Use the most suitable option for launching OPTFEKO in Linux.
- Command Line Arguments for Launching OPTFEKO
  Use the command line arguments to pass additional information to OPTFEKO when it is launched.
- Optimisation Methods and Stopping Criteria
  The duration and accuracy of an optimisation depends on the selected optimisation method and stopping criteria.
- Optimisation Parameters
  Specify the variables to alter during the optimisation run.
- Optimisation Masks
  An optimisation mask is a graphical approach to define an optimisation search. More complex scenarios are handled by a mask, where the goal shape is visually known, for example, the desired bandpass and bandstop regions of a filter.
- Defining an Optimisation Goal
  An optimisation goal defines the request type to be optimised and the goal it will attempt to achieve.
- Global Goal: Combining and Weighting of Multiple Goals
  Specify the method for combining multiple goals. A weight or importance factor is assigned to the combined goal and optimised according to the combination type, for example, the average of the goals combined for the specified data.
- Optimisation Using .PRE File modifications
  Use optimisation with modifications made in the .pre file in EDITFEKO.
- Optimisation Solver Settings
  Make adjustments to the optimisation settings for a more computationally efficient 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.

Optimisation Using .PRE File modifications

Use optimisation with modifications made in the .pre file in EDITFEKO.

The optimiser operates on solution requests specified in CADFEKO. However, for advanced users, it is possible to make use of the optimiser after making modifications to the .pre file in EDITFEKO.

The optimiser operates on the labels of the solution requests. These labels are usually created in CADFEKO, but are copied to the .pre file. The optimiser reads the labels from the .pre file.

Consider the patch antenna on a finite substrate in Figure 1.

Figure 1. A patch antenna on a finite substrate fed with a voltage source on a wire port.

The antenna is fed with a voltage source on a wire port. Unless edited by the user, the voltage source is created with a default label of VoltageSource1 in CADFEKO. When the CADFEKO model is saved, a .pre file is created by CADFEKO.

To open the .pre file, run EDITFEKO from within CADFEKO.

In EDITFEKO the .pre file contains an A1 card with the label, MyCustomVoltageSource1 (label following after **), see Figure 2.

Figure 2. Screenshot of the A1 card (voltage source on a wire segment) in the .pre file.

New sources and output requests can be added to the .pre file. For each request that will be used for optimisation, a unique label must be specified. After the .pre file is edited and saved, the optimisation setup is completed in CADFEKO by manually entering the label of the parameter to be optimised in the Focus source label text box in the Goal focus group.

Figure 3. A snippet of the impedance optimisation goal dialog using a custom label.