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

The E-plane contains the electric field vector E and the direction of maximum radiation. The H-plane contains the magnetic field vector H and the direction of maximum radiation. These two planes are always perpendicular to each other. For a vertically polarized antenna: the E-plane is any vertical plane through the antenna axis (elevation pattern), and the H-plane is the horizontal plane (azimuth pattern). For a horizontally polarized antenna: the E-plane is horizontal and the H-plane is vertical. In rectangular waveguide operating in TE10 mode: the E-plane is the narrow wall plane (y-z plane, containing Ey) and the H-plane is the broad wall plane (x-z plane, containing Hx and Hz).

What are E-plane waveguide components?

E-plane bend: the waveguide turns in the E-plane (narrow wall dimension changes direction). Requires a gradual bend radius of at least 1.5 times the guide wavelength for low VSWR. E-plane T-junction (series tee): a branch waveguide joins perpendicular to the main guide in the E-plane. The branch signal splits 180 degrees out of phase between the two main ports. Used as a subtractive power divider. E-plane horn: the waveguide flares in the E-plane (height increases), producing a fan beam narrow in the E-plane and wide in the H-plane. E-plane sectoral horns have beamwidths from 10 to 60 degrees depending on flare angle and length.

How do E-plane patterns relate to antenna design?

E-plane and H-plane radiation patterns are the two principal cuts through the three-dimensional antenna pattern. For a rectangular aperture antenna (horn, patch, slot array), the E-plane beamwidth is determined by the aperture dimension in the E-field direction. A larger E-plane dimension produces a narrower E-plane beamwidth: BW_E approximately equals 51 times lambda divided by the E-plane aperture dimension (in degrees, for uniform illumination). Cross-polarization is typically higher in the diagonal planes (45 degrees between E and H) than in the principal planes. For horn antennas, matched E-plane and H-plane beamwidths produce the lowest cross-polarization, which is the design goal of corrugated and dual-mode horns used as feed antennas for reflector dishes.

Field Orientation

E-Plane

/ee-playn/ — Electric Field Plane

The plane containing the E-field vector and direction of maximum radiation/propagation. Perpendicular to H-plane. Vertical dipole: E-plane = vertical (elevation). Waveguide TE₁₀: E-plane = narrow wall (y-z, contains E_y). E-plane components: bends, T-junctions (series tee, 180° split), sectoral horns. Beamwidth: BW_E ≈ 51λ/D_E degrees (uniform aperture).

Contains: E-field

⊥ to: H-plane

BW: 51λ/D

Understanding E-Plane

The E-plane and H-plane are the two principal reference planes in antenna engineering and waveguide design. Every antenna radiation pattern is characterized by cuts in these two planes, providing the essential information about beamwidth, sidelobe levels, and cross-polarization. Similarly, waveguide components are classified as E-plane or H-plane depending on their orientation relative to the electric field.

Understanding which plane is the E-plane is critical for proper system integration. When connecting a horn antenna to a rectangular waveguide, the E-plane flare determines the elevation beamwidth, while the H-plane flare controls the azimuth pattern. Mixing up these planes results in a rotated polarization and incorrect coverage patterns.

E-Plane Equations

E-plane beamwidth (uniform):
BW_E = 51λ/D_E (degrees)
D_E = aperture dimension in E-plane

H-plane beamwidth:
BW_H = 69λ/D_H (degrees)
(Different illumination taper)

E-plane horn gain:
G = 4πA_eff/λ²
A_eff = η_ap × a × b_E
η_ap ≈ 0.5-0.8 (aperture efficiency)

E-Plane vs H-Plane Components

Component	E-Plane	H-Plane	Effect	Application
Bend	Narrow wall	Broad wall	Direction change	Routing
T-junction	Series (180°)	Shunt (0°)	Power split	Combiner
Horn	Height flare	Width flare	Beamwidth	Feed antenna
Pattern cut	Elevation	Azimuth	Coverage	Antenna test
Polarization	Co-pol plane	Cross-pol min	Purity	Feed design

Common Questions

Frequently Asked Questions

E vs H plane?

E-plane: contains E-field + max radiation direction. H-plane: contains H-field + max radiation. Always perpendicular. Vertical antenna: E=elevation, H=azimuth. Waveguide TE10: E=narrow wall (y-z), H=broad wall (x-z). Determines component naming and pattern cuts.

Waveguide components?

E-bend: narrow wall changes direction, R≥1.5λg for low VSWR. E-tee: series junction, 180° phase split (subtractive divider). E-horn: height flare, narrow E-plane beam, wide H-plane. E-plane sectoral: 10-60° beamwidth depending on flare/length.

Pattern design?

BW_E = 51λ/D_E (uniform illumination). Larger E-dimension = narrower beam. Cross-pol highest in 45° diagonal planes. Matched E/H beamwidths = lowest cross-pol (corrugated/dual-mode horns for reflector feeds). Critical for satellite feed antennas.

Related Terms

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