directivity
Sign in to savethumb|right|Diagram showing directivity: the highest power density of this antenna is in the direction of the red lobe
Article
12 sectionsContents
- Definition
- In antenna arrays
- Relation to beam width
- Expression in decibels
- Accounting for polarization
- Partial directive gain
- Partial directivity
- Partial gain
- In other areas
- See also
- References
- Further reading
thumb|right|Diagram showing directivity: the highest power density of this antenna is in the direction of the red lobe
In electromagnetics, directivity is a parameter of an antenna or optical system which measures the degree to which the radiation emitted is concentrated in a single direction. It is the ratio of the radiation intensity in a given direction from the antenna to the radiation intensity averaged over all directions. Therefore, the directivity of a hypothetical isotropic radiator, a source of electromagnetic waves which radiates the same power in all directions, is 1, or 0 dBi.