What Is an Antenna Radiation Pattern?

An antenna radiation pattern (also called an antenna pattern) is a graphical representation of how a specific antenna radiates or receives electromagnetic energy in space. It shows the relative signal strength in every direction around the antenna, and every antenna has a unique radiation pattern determined by its physical design, electrical properties, and operating frequency.

This guide explains how the antenna radiation pattern is plotted, how polarization (linear, vertical, and horizontal) relates to the E-Plane and H-Plane, how the XY, XZ, and YZ planes correspond to those fields, and how installers read beamwidth, gain and front-to-back ratio straight off the plot.

Radiation patterns are formed by plotting the antenna’s far-field radiation characteristics (the normally radiating field) as charted coordinates, usually shown in polar or Cartesian plots. Antenna patterns are essential for visualizing how an antenna will perform once mounted in its intended orientation. For accurate planning and deployment—especially in wireless networking—radiation patterns must be measured and plotted in the same orientation in which the antenna will be used.

How 3D Radiation Patterns Are Represented in Two Dimensions

Antennas radiate and receive energy in three dimensions. However, visualizing full 3D patterns is impractical for most applications. Instead, antenna patterns are commonly represented as 2D slices through the 3D radiation field, known as principal plane patterns.

These planes intersect at the antenna’s origin and provide a reliable representation of antenna performance when derived from a true 3D dataset.

The Principal Radiation Planes

• Azimuth Plane (XY Plane)

  • Also known as the horizontal plane

  • Represents radiation around the antenna in a 360° sweep

• Elevation Plane (YZ Plane)

  • Also called the vertical plane

  • Oriented at right angles to the azimuth plane

• XZ Plane

  • A third perpendicular plane that also intersects the antenna origin

  • Provides additional cross-sectional data for pattern verification

These intersecting planes produce complementary radiation plots that, together, describe the antenna’s directional behavior.

Important: For accuracy, these plots should be derived from a true cross-section of a measured or simulated 3D radiation pattern, not independently generated curves.

Linearly Polarized Antennas

Polarization refers to the orientation of the electric (E) field and magnetic (H) field of an electromagnetic wave as it propagates away from an antenna.

In linearly polarized antennas, the electric field oscillates in one fixed plane. The antenna restricts radiation to this single linear direction.

Depending on the antenna’s orientation relative to the earth, linear polarization may be:

• Vertical polarization

  • The electric field oscillates in the vertical plane

• Horizontal polarization

  • The electric field oscillates in the horizontal plane

When interpreting the radiation patterns of linearly polarized antennas, the following planes are used.

The E-Plane (Electric Field Plane)

The E-Plane is defined as:

• The plane containing the electric field vector

• The direction of maximum radiation

The E-Plane determines whether an antenna is vertically or horizontally polarized.

• Vertically polarized antennas

  • E-Plane coincides with the vertical / YZ / elevation plane

• Horizontally polarized antennas

  • E-Plane coincides with the horizontal / XY / azimuth plane

The H-Plane (Magnetic Field Plane)

The H-Plane represents the plane containing the magnetic field component of the electromagnetic wave.

Key characteristics:

• Always perpendicular to the E-Plane

• Often referred to as the azimuth plane for vertically polarized antennas

Examples:

• A vertically polarized antenna

  • H-Plane coincides with the horizontal (XY) azimuth plane

• A horizontally polarized antenna

  • H-Plane coincides with the vertical (YZ) elevation plane

Radiation Patterns Labeled XY, XZ, and YZ

Radiation patterns may be labeled directly by their Cartesian planes rather than E-Plane or H-Plane terminology. This applies regardless of whether the antenna is vertically or horizontally polarized.

• XY Plane Radiation Pattern

  • Represents the horizontal (azimuth) radiation pattern

  • Perpendicular to the E-Plane

  • Coincides with the H-Plane of a vertically polarized antenna

• YZ Plane Radiation Pattern

  • Represents the vertical (elevation) radiation pattern

  • Coincides with the E-Plane of a vertically polarized antenna

• XZ Plane Radiation Pattern

  • Provides an additional orthogonal slice

  • Useful for validating symmetry and side-lobe behavior

Reading Beamwidth, Gain and Front-to-Back Ratio From the Pattern

Beyond polarization, the radiation pattern is where you read the three numbers that drive antenna selection: beamwidth, gain and front-to-back ratio. These are what separate an omnidirectional antenna from a directional antenna on paper.

• Half-power beamwidth (HPBW) — the angular width of the main lobe measured between the two points where power drops to half (−3 dB) of the peak. A narrow beamwidth concentrates energy over a longer range; a wide beamwidth covers more area at shorter range. Azimuth and elevation beamwidth are read from the XY and YZ plots respectively.

• Gain (dBi) — higher gain shows up as a longer, narrower main lobe. Gain does not add power; it reshapes the pattern, trading coverage angle for range. A 2–5 dBi omni radiates a broad doughnut; a 12–24 dBi Yagi or panel squeezes that energy into a tight forward beam.

• Front-to-back ratio — the difference in dB between the main lobe and the lobe pointing 180° behind it. A high front-to-back ratio means the antenna rejects interference and noise arriving from the rear, which matters for point-to-point links and co-located radios.

• Side lobes and nulls — smaller lobes off the main beam (side lobes) and the deep minima between them (nulls) reveal where an antenna will and will not hear a signal. The XZ slice is used to validate side-lobe symmetry.

When you compare datasheet patterns this way, two antennas with the same nominal gain can behave very differently in the field depending on beamwidth and front-to-back performance.

Why This Matters in Real-World Antenna Deployment

Understanding how E-Planes, H-Planes, and principal radiation planes relate allows engineers and installers to:

• Select antennas with appropriate coverage

• Optimize antenna orientation and mounting height

• Reduce polarization mismatch losses

• Improve link reliability in wireless networks

Summary Table

Conclusion

Antenna radiation patterns provide a critical window into how an antenna transmits and receives energy in real-world deployments. By understanding how three-dimensional radiation behavior is represented through principal plane slices—specifically the XY, YZ, and XZ planes—engineers and installers can accurately interpret antenna performance using practical two-dimensional plots.

Equally important is recognizing the relationship between polarization and the E-Plane and H-Plane. The orientation of the electric field determines polarization, while the perpendicular magnetic field defines the complementary plane. Misinterpreting these relationships can lead to incorrect antenna selection, improper mounting orientation, and unnecessary signal loss due to polarization mismatch.

When radiation patterns are correctly measured, labeled, and interpreted in the same orientation as their intended installation, they become a powerful tool for network planning and optimization. Need help matching a pattern to your coverage requirement? Browse Data Alliance antennas or contact our technical support team for a recommendation.

Antenna Radiation Pattern FAQs

What is an antenna radiation pattern?

An antenna radiation pattern is a graphical representation of how an antenna radiates or receives electromagnetic energy in space. It shows the relative signal strength in different directions and is determined by the antenna’s design, electrical properties, and operating frequency. Radiation patterns are typically plotted using far-field data in polar or Cartesian formats.

Why are antenna radiation patterns shown in 2D instead of 3D?

Although antennas radiate energy in three dimensions, full 3D patterns are difficult to visualize and interpret. For practical use, radiation patterns are shown as 2D cross-sections—called principal plane patterns—taken from a true 3D dataset. These 2D plots provide accurate insight into antenna performance while remaining easy to analyze.

What are the XY, YZ, and XZ planes in antenna radiation patterns?

The XY plane is the horizontal or azimuth plane, showing 360° radiation around the antenna. The YZ plane is the vertical or elevation plane, perpendicular to the XY plane. The XZ plane is a third orthogonal plane used for additional pattern verification. Together, these planes describe the antenna’s directional behavior.

What is the difference between the E-Plane and H-Plane?

The E-Plane contains the electric field and the direction of maximum radiation, and it determines whether the antenna is vertically or horizontally polarized. The H-Plane contains the magnetic field and is always perpendicular to the E-Plane. Both planes are used to interpret the radiation patterns of linearly polarized antennas.

How do the E-Plane and H-Plane relate to vertical and horizontal polarization?

For vertically polarized antennas, the E-Plane is the YZ (vertical / elevation) plane and the H-Plane is the XY (horizontal / azimuth) plane. For horizontally polarized antennas, the E-Plane is the XY (horizontal / azimuth) plane and the H-Plane is the YZ (vertical / elevation) plane. This relationship is essential for correct antenna alignment and system design.

How do you read beamwidth, gain and front-to-back ratio from a radiation pattern?

Half-power beamwidth is the angular width of the main lobe between its two −3 dB points, read from the azimuth (XY) and elevation (YZ) plots. Higher gain appears as a longer, narrower main lobe—energy is concentrated into a smaller angle rather than added. Front-to-back ratio is the dB difference between the main lobe and the lobe 180° behind it, indicating how well the antenna rejects interference from the rear.

Why is understanding radiation planes important for antenna installation?

Understanding radiation planes helps engineers and installers select the right antenna, orient it correctly, and minimize polarization mismatch. Proper interpretation of E-Plane, H-Plane, and XY/YZ/XZ patterns improves coverage, reduces signal loss, and enhances overall wireless link reliability.