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Radiation pattern

The Radiation Pattern tab shows the far-field directivity of the antenna as a 3D surface or as 2D polar cuts. It opens automatically when a run completes with Compute Radiation Pattern enabled.

Polar view

The Polar view shows the standard 2D cuts (E-plane and H-plane). The right-side panel holds a Frequency slider, a Metrics block (Directivity max, HPBW theta and phi, sidelobe, F/B ratio), and Display toggles for the E-plane and H-plane traces.

3D pattern

Click 3D Pattern for the colour-mapped lobe. The lobe is the far-field gain in dBi (red is the peak, purple is the nulls). The geometry is overlaid at scale so you can see where the beam is pointing relative to the antenna.

  • The Frequency slider in the right panel scrubs across the simulated band. Patterns are stored per-frequency, so you can watch the lobe evolve.
  • Pattern Opacity and Geometry Opacity control the alpha blend between the lobe and the geometry.
  • Auto scale sizes the lobe to the geometry. Turn it off and edit Scale directly for fixed-size renders across multiple frequencies.

Geometry visibility

Drop the geometry opacity to see into the lobe interior. Useful for steered arrays or anywhere the geometry occludes the backlobe.

Frequency scrubbing

Drag the Frequency slider to step through the simulated band. The lobe shape changes with frequency: off-resonance points usually produce a broader, less directional lobe.

Split view

The Split View button puts the 3D and Polar views side by side. The frequency slider drives both at once, which is the quickest way to confirm the polar cuts agree with the 3D lobe at each frequency.

Metrics

  • Directivity max. Peak directivity in dBi at the selected frequency.
  • eta rad. Radiation efficiency, reported when input-power telemetry is available.
  • HPBW theta / phi. Half-power beamwidth in the principal cuts.
  • Sidelobe. Peak sidelobe level relative to the main beam.
  • F/B ratio. Front-to-back ratio, useful for directional antennas.

When NF2FF is not enabled

If a run completed without Compute Radiation Pattern, the polar plot is empty and every metric reads ---. Re-run with the option enabled at Medium quality or higher to populate the pattern.

Export

Export CSV on the Polar view saves the displayed E-plane and H-plane data as comma-separated values for processing in Python, Octave, or a spreadsheet. PNG export of the pattern view is on the roadmap. For now use a system screenshot if you need an image of the 3D lobe.