Antenna Radiation Patterns:

This article explains antenna radiation patterns, detailing how polarization (linear, vertical, and horizontal) relates to the E-Plane and H-Plane, and how the XY, XZ, and YZ planes correspond to those fields.

What Is an Antenna Radiation Pattern?

A radiation pattern, or antenna pattern, is a graphical representation of how a specific antenna radiates or receives electromagnetic energy in space. Each antenna has a unique radiation pattern, determined by its physical design, electrical properties, and operating frequency.

Radiation patterns are formed by plotting the antenna’s far-field radiation characteristics (the normally radiating field) as charted coordinates, often 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

AZIMUTH PLANE: The Magnetic H plane (or H aperture)

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

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. A solid grasp of E-Plane, H-Plane, and Cartesian plane representations enables more reliable wireless links, improved coverage, and better overall system performance across a wide range of RF and wireless applications.