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Antenna Gain Formula:
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Antenna gain is a key performance parameter that measures the directionality and efficiency of an antenna. It represents how well the antenna converts input power into radio waves in a specific direction compared to an isotropic radiator.
The calculator uses the antenna gain formula:
Where:
Explanation: The formula calculates the antenna gain in dBi (decibels relative to an isotropic radiator) by combining the efficiency and directivity parameters in logarithmic scale.
Details: Accurate antenna gain calculation is crucial for designing wireless communication systems, optimizing signal strength, and ensuring proper coverage in various applications including telecommunications, broadcasting, and radar systems.
Tips: Enter antenna efficiency (between 0 and 1) and directivity (≥0). Both values must be valid dimensionless numbers.
Q1: What is the difference between gain and directivity?
A: Directivity measures the concentration of radiation in a particular direction, while gain accounts for both directivity and efficiency losses in the antenna system.
Q2: What are typical antenna gain values?
A: Gain values vary widely depending on antenna type. Simple dipoles have about 2.15 dBi gain, while highly directional antennas can have gains of 20 dBi or more.
Q3: Why is antenna gain measured in dBi?
A: dBi means "decibels relative to an isotropic radiator," which is a theoretical antenna that radiates equally in all directions, providing a standard reference point.
Q4: How does efficiency affect antenna gain?
A: Efficiency represents how much input power is actually radiated versus lost as heat. Lower efficiency results in lower gain even with high directivity.
Q5: Can antenna gain be negative?
A: Yes, antenna gain can be negative in dBi if the antenna performs worse than an isotropic radiator, which typically occurs with very inefficient antennas.