Far-Field Calculator

Far-Field Formula

The formula to calculate the far-field distance (dF) is:

\[ d_F = \frac{2 \times D^2}{\lambda} \]

Where:

• \(d_F\) is the far-field distance.
• \(D\) is the diameter of the antenna.
• \(\lambda\) is the wavelength of the radio wave.

Example Calculation

If the diameter of the antenna is 5 meters and the wavelength of the radio wave is 0.1 meters, the far-field distance would be:

\[ d_F = \frac{2 \times 5^2}{0.1} = \frac{2 \times 25}{0.1} = \frac{50}{0.1} = 500 \text{ meters} \]

What is a Far-Field?

Definition: The far-field, also known as the Fraunhofer region, is the area where the angular field distribution does not change with distance from the antenna. In this region, the electromagnetic waves radiating from the antenna are essentially planar and the pattern is independent of the distance from the antenna.

How to Calculate Far-Field?

To calculate the far-field, you need to know the diameter of the antenna and the wavelength of the radio wave. Using the formula provided, plug in the values to compute the distance at which the far-field conditions dominate.