Getting started

1. Install

Download the installer from the download section or the releases page.

• macOS (Apple silicon, macOS 27 or newer): open the .dmg and drag Fairbeam to Applications. The app is signed and notarized by Apple, so it opens with a normal double-click.
• Windows (10/11, x64): run the -setup.exe. It installs for your user, without an administrator prompt. The installer is not signed yet, so SmartScreen shows “Windows protected your PC”: choose More info › Run anyway.

First start. Fairbeam needs its simulation runtime (Python, openEMS and the Fairbeam package). The setup screen says “Fairbeam needs to install its runtime”: choose Install the runtime (the button shows the download size; it takes well under a minute on a fast connection). If you already have an openEMS installation, Use an existing Python… points Fairbeam at it instead. The app then opens on the Start screen. Later starts skip this step, and newer versions are offered in the app (Help › Check for updates).

2. A five-minute walkthrough

Create a design

1. On Start, under New project, type a name (for example My patch), pick Patch antenna starter (“Probe-fed patch over a ground plane”, under Printed) and click Create and open the designer. The other starting points are ready-to-run parametric designs: Empty project (a band, copper and FR4, no geometry), Half-wave dipole, Quarter-wave monopole and Open-ended waveguide (under Basic antennas), Printed sleeve dipole (867 MHz, no ground plane; under Printed) and Microstrip line (two-port) (50 Ω on FR-4, for S11 and S21; under Circuits). Each simulates in seconds; this guide follows the patch.
2. The designer opens. Take a look around:
   • the ribbon at the top: Home, Modeling, Transform, Simulation, Optimize, Post-processing;
   • the navigation tree on the left: the design, Parameters (6: f0, W, L, h, G, feed), Components (Substrate, Ground plane, Patch, each with its shape), Materials, Ports (Port 1, 50 Ω) and Results (none yet);
   • the 3D view in the middle: drag to orbit, scroll to zoom, right- or middle-drag to pan; Iso / Top / Front / Right / Bottom set the camera and the target button (or Space / F) fits the model;
   • Properties on the right: the fields of what you select;
   • the dock at the bottom: Checks and Parameters, and later Run (the live progress), Runs (the design’s runs side by side) and Log. The plots of a run open as tabs beside the 3D view.
3. Click Patch in the tree (or on the model) to see its brick: every value can be a number or an expression over the parameters, such as W/2.
4. Right-click a part in the tree or in the 3D view for Hide, Rename, Transform…, Duplicate, Delete, Add a lumped port, Move to component › and the Boolean operations. A part moved to a component shows in a folder of the tree; right-click the folder to rename, ungroup or delete it.

Simulation settings

Open the Simulation tab of the ribbon:

• Frequency band: f min and f max in GHz. The starter uses f0 * 0.6 to f0 * 1.3, around its design frequency f0 = 2.45 GHz.
• Boundaries: the six faces of the simulation box, each open (MUR or PML), an electric wall (PEC) or a magnetic wall (PMC). The patch starter uses MUR on all six.
• Mesh: Cells / λ sets the automatic mesh density; Mesh settings has the details, Mesh convergence… checks whether the mesh is fine enough (see below) and Mesh view draws the mesh in the 3D view. The status bar shows the cell count and the smallest cell.
• Ports: Lumped, Waveguide and Resistor add a port or a load.
• Monitors:
  • Far field: the radiation pattern, directivity and gain at the listed frequencies (the starter records it at f0).
  • Surface current: adds surface-current maps on the metal sheets at the frequencies you list.
  • Efficiency: adds Efficiency over the band, the radiation and total efficiency at evenly spaced frequencies from f min to f max (post-processing, no extra solver time).
  • Field plane: adds an E or H field map on a cut plane through the model (up to four planes, each at one to four frequencies); a new one starts just above the model.

  Each of these buttons opens Simulation settings at that section; OK keeps the changes, Cancel restores the settings from before.

• Solver limits: the end criterion (−60 dB in the starters; an empty project starts at −50 dB) and the maximum number of timesteps.

The Checks tab of the dock lists anything that stops a run; the status bar shows “Checks passed” when there is nothing to fix.

Run

Click Run (Simulation tab, or the Run button at the top, or Ctrl/⌘+Enter). The Run the simulation dialog shows:

• Engine: CPU (multi-threaded) with the number of Threads (4 is a good default), or GPU (Metal or CUDA build) when the GPU build of openEMS is installed;
• S-parameter sample points (801 by default) and an optional Result name;
• a solver time estimate.

Click Run. The design is saved first; the progress (timesteps, energy decay) shows in the dock. The starter takes seconds to a minute, depending on the machine.

Results

When the run is done it appears under Results in the tree, with its time and engine:

• 1D Results › S-parameters opens |S11| as a tab next to the 3D view. Click Markers on the plot (or press M) for Add marker, Previous minimum / Next minimum, Automatic markers below a threshold, and a table you can copy.
• 1D Results › Smith chart, Impedance, VSWR, and Efficiency (the mismatch efficiency over the band, with the radiation and total efficiency from the monitor).
• Farfields › 3D pattern (f = …) draws the pattern on the model in the 3D view, with the far-field card beside it: pick Directivity, Gain or Realized gain, and read the maximum, the gain, the realized gain and the radiation and mismatch efficiency. Farfield (f = …) opens the pattern cuts as a tab.
• 2D/3D Results › Surface current (with the monitor) shows the current map on the metal, and a field-plane node such as E-field (z = … mm, … GHz) (with the Field plane monitor) draws the E or H map as a heat-map plane in the 3D view, with a color bar in dB or linear; its 2D map node opens it as a heat map tab with axes, a hover readout and the model's outline, and Phase / Animate show the phase and the field over one period.
• Tables and Log.

The Post-processing tab of the ribbon opens the same views. Choosing a geometry tab (Home, Modeling, …) or clicking a part takes the pattern off the 3D view and shows the design again.

Change a parameter and compare runs

1. Click Parameters in the tree (it opens the Parameters tab of the dock) and change W, the patch width, for example from 32 to 30 mm. The 3D view follows at once.
2. Run again. Results now lists two runs, the newest first.
3. Ctrl/⌘-click both runs in the tree (or use Compare in the result tab’s toolbar, or click their labels in the dock’s Runs tab): the plots draw them together, one color each (up to eight runs).

Is the mesh fine enough?

Simulation › Mesh convergence… runs the design at finer and finer automatic meshes (15, 20, 30 and 40 cells per wavelength by default) and compares each run with the previous one: the resonance frequency, |S11| at the resonance and, with the far field on, the maximum directivity. Before it starts, the dialog shows the number of cells and a time estimate for every density; Start saves the design and queues the first run, and the next one only when the previous is done and the results are still changing. The study stops at the first step whose changes are all below the tolerances and reports converged at N cells/λ; Apply N cells/λ to the design sets that density (Undo takes it back). The runs appear under Results in one Mesh convergence folder, whose Convergence report opens the table and plots again. If it reports not converged, refine further or check the model.

A parameter sweep

Optimize › Parametric sweep opens Parameter Sweep: Add parameter, choose it (for example Patch width (x) (W)), then Evenly spaced values with Start, Stop and Sample count, or a Value list. Check shows how many simulations that makes; Start saves the design and queues them. The runs appear under Results in one Sweep folder; right-click it for Compare all runs.

The optimizer

Optimize › Optimizer opens Optimize design:

• Vary: the parameters to change, with a starting value and Min / Max bounds;
• Goals: for example Tune resonance to 2.45 GHz, Match at, Maximize bandwidth or Directivity at least, each with a weight;
• Evaluations ≤, Threads and the Method (Auto picks the secant method for one parameter tuned to a frequency; Nelder–Mead, Bayesian, CMA-ES and others for more).

Start optimization runs one simulation per evaluation, with the progress in the dock. The optimization then appears under Results with Optimization history, Open best, Save best as a run and Apply best parameters to design.

3. Import a VBA macro

On Start, Import VBA macro… (also Home › Project › Import VBA macro, or File › Import VBA macro… in the desktop app) reads a CST-compatible VBA macro (.bas, .mcs) or a history list saved as text. Before anything is saved it shows a report: what was created, and every command that was skipped or changed, with its line. Name the design and Create and open it.

4. Where your files are

Everything lives in the workspace folder, Documents/Fairbeam in your home folder (Windows: %USERPROFILE%\Documents\Fairbeam):

The gear button at the top (General settings) shows the Workspace folder with an Open folder button, the Language of the interface (System, English or Türkçe, native menus included) and the Decimal separator for numbers shown as text. The examples on the Start screen are copies: Open as new project… makes a design of your own from one, and the original stays unchanged.

5. Report a problem

At the bottom of the Start screen, Send feedback: Report a problem (or Suggest a feature) opens the issue form of the public tracker, fairbeam-releases/issues, in your browser with the app version and your operating system filled in. The speech-bubble button at the top (Send feedback) and Help › Report a Problem… do the same from any screen. Fairbeam sends nothing by itself.

Helpful to include: what you did and what you expected, a screenshot (Home › View › Screenshot saves a PNG of the 3D view), the design file from models/, and the run’s log (Results › your run › Log).

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