Antenna 3db Beamwidth Calculator

The 3dB beamwidth of an antenna is a crucial parameter in the field of antenna theory. It defines the range of directions in which the antenna radiates power effectively. The '3dB' indicates that the beamwidth is the angle at which the power reduces to half its peak value. This is a fundamental concept in wireless communications and signal processing.

Antenna 3db Beamwidth Calculator
Antenna 3db Beamwidth Calculator Results
3 dB Beamwidth = degrees

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The formula to calculate the 3dB beamwidth of an antenna depends on the type of the antenna. A common type is the parabolic antenna, and its 3dB beamwidth (B) can be approximated using the formula:

B = 70λ / D
  1. λ: wavelength of the signal.
  2. D: diameter of the antenna.

Who wrote/refined the formula

The concept of beamwidth and its formulas have been derived and refined by many researchers and engineers in the field of antenna theory and wireless communication over the years. While it's difficult to attribute the formula to a specific individual, the development of antenna theory in general can be linked to figures such as James Clerk Maxwell and Heinrich Hertz, who laid the groundwork for electromagnetic wave theory.

Real Life Application

The 3dB beamwidth is a vital parameter for antenna installation in wireless communication systems, like in mobile communication towers, satellite communication, radio astronomy, and radar systems. It helps in determining the coverage area of the antenna and also impacts the design of the antenna array to achieve the desired signal coverage and quality.

Key individuals in the discipline

James Clerk Maxwell and Heinrich Hertz are considered pioneers in the field of electromagnetism and radio wave propagation. Their work laid the foundation for the development of antenna theory. Later, Guglielmo Marconi, known as the father of long-distance radio transmission, also made significant contributions to the field.

Interesting Facts

  1. Beamwidth not only applies to transmitting antennas but also to receiving antennas. A smaller beamwidth results in a more focused and narrow reception, leading to higher quality signals.
  2. Beamwidth, especially the 3dB beamwidth, is a key parameter that shapes the evolution of communication technology, playing a significant role in the deployment of cellular networks and satellite communications.
  3. 3dB beamwidth is also used in audio signal processing, where it influences the design of loudspeakers and microphones.


The concept of 3dB beamwidth in antenna theory is instrumental in the field of wireless communications. It enables the efficient design and deployment of antenna systems to provide optimal signal coverage and quality. As technology progresses, understanding and applying this concept will continue to be a key factor in shaping future communication systems.

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