Antenna Parameters
Antenna Gain
The ratio of radiation intensity in a given direction to the intensity that would be produced if the power were radiated isotropically, expressed in dBi
Understanding Antenna Gain
Antenna gain combines the directivity of the radiation pattern with the radiation efficiency. A high-gain antenna concentrates energy into a narrow beam, increasing effective radiated power in the desired direction without increasing transmitter power.
Gain is typically referenced to an isotropic radiator (dBi) or a half-wave dipole (dBd), where 0 dBd equals approximately 2.15 dBi. Gain increases with antenna aperture size relative to wavelength.
Common Questions
Frequently Asked Questions
How is antenna gain measured?
Gain is measured in an anechoic chamber or outdoor range by comparing the antenna under test to a reference antenna with known gain.
Does higher gain mean better performance?
Higher gain provides more signal strength in the main beam direction but narrows the beamwidth, requiring more precise pointing.
See Also