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Antenna Gain and Effective Area: Formulas and Types

antenna gain effective area parabolic isotropic

The relationship between an antenna’s gain and its effective area is crucial in understanding its performance characteristics. This concept applies to various antenna types, such as parabolic dishes, horn antennas, and dipoles. The gain of an antenna indicates its ability to focus energy in a particular direction, while the effective area defines the portion of power that can be effectively received or transmitted. By exploring these parameters, engineers can optimize antenna designs for specific applications in communication, broadcasting, and radar systems.

This page provides formulas for different antenna types to clarify the gain and effective area relationship.

Antenna Gain (G)

$G = \frac{4 \pi A_e}{\lambda^2} = \frac{4 \pi f^2 A_e}{c^2}$

Where:

$G$ = antenna gain of parabolic dish
$A_e$ = Effective area
$f$ = Carrier frequency
$c$ = Speed of light
$\lambda$ = Carrier wavelength
$\pi$ = 3.14

Parabolic Reflector Antenna

Figure: Parabolic Reflector Antenna

Antenna Types with Gain and Effective Area Formula

Antenna Type	Effective Area, meter $^2$	Power Gain relative to Isotropic Antenna
Isotropic	$\lambda^2 / 4\pi$	1
Infinitesimal dipole or loop	$1.5 \lambda^2 / 4\pi$	1.5
Half-wave dipole	$1.64 \lambda^2 / 4\pi$	1.64
Horn, mouth area A	$0.81 A$	$10 A / \lambda^2$
Parabolic, face area A	$0.56 A$	$7 A / \lambda^2$
Two crossed, perpendicular dipoles	$1.15 \lambda^2 / 4\pi$	1.15

Conclusion

Understanding the interplay between an antenna’s gain and its effective area is essential for selecting the right antenna for your application. Whether it’s a high-gain parabolic dish for satellite communication or a horn antenna for directional signal transmission, knowing how these parameters influence performance ensures better system efficiency and reliability. By comparing various antenna types, you can make informed decisions that optimize signal strength and coverage, enhancing overall communication quality.