This calculator determines the effective aperture of an antenna (Ae) from its gain and its operating frequency. It allows us to understand the relationship between the physical size of the antenna, its gain and its ability to capture or transmit electromagnetic energy.
Useful for RF engineers, communications system designers and students wishing to estimate the reception performance of an antenna based on frequency and gain.
Formulas
Ae = (λ² / (4 × π)) × G
Or
Ae = (c² / f²) × (G / (4 × π))
Explanation of formulas
- Ae represents the effective aperture of the antenna, expressed in square meters.
- λ is the wavelength calculated from the speed of light (c) divided by the frequency (f).
- G is the antenna gain in linear scale (converted from dBi by 10^(GdBi/10)).
- An antenna with higher gain or lower frequency has a larger effective aperture.
120 MHz antenna gain 11 dBi effective aperture
Input : f = 120 MHz, G = 11 dBi
Output : Ae ≈ 6.25 m²
Benefits and uses
- Allows you to evaluate the reception efficiency of an antenna.
- Useful for designing RF, radar or satellite systems.
- Provides a clear estimate of the relationship between antenna size and performance.
- Useful for comparing different antenna designs at varying frequencies.