Exploring the radiation pattern of a half-wave dipole antenna

Visualising the directional pattern in which energy is radiated or received.

The half-wave dipole antenna is formed from a conducting element, which is a wire of length equal to one half of the wavelength at the frequency of operation. Such an antenna emits an omnidirectional radiation pattern.

The animation above displays this doughnut-shaped pattern in 3D, before slicing a cross section perpendicular to the axis to display a 2D profile of the pattern. Along the cut plane, the surface shape is clearly visible.

Reception is strongest when perpendicular to the conductor and weakest along the axial direction. The greatest signal strength is shown coloured red, while zero strength is shown in deep blue.

A cross section of a half-wave dipole antenna radiation pattern.

The image here shows a cross section slightly offset from the centre of the torus-like pattern.

Half-wave dipole antennas are widely used in radio and other VHF communication applications. These antennas can be used in various configurations, depending on the application and frequency range.

Unlike directional antennas that focus on signals from a specific direction, the dipole is designed to send and receive signals equally from all directions.

3D interactive model showing the sliced pattern of a half-wave dipole antenna.

The 3D model above allows viewers to explore a half-wave dipole antenna interactively. A normalised version of an ideal dipole antenna is also available to view.

Note that in all cases shown here, the antenna is assumed to be positioned high enough so as not to be affected by the ground.

Learn more about this subject with an immersive learning experience demonstrating electric and magnetic components in action.

Looking at the zero degree null of a dipole antenna radiation pattern.