Alvarion BREEZENET RB-DS.11 - Manual (Page 87)

Radio Signal Propagation
C-3
Antenna Characteristics
Isotropic Antenna
A hypothetical antenna having equal radiation intensity in all directions. Used as a
zero dB gain reference in directivity calculation (gain).
Antenna Gain
A measure of directivity. It is defined as the ratio of the radiation intensity in a
given direction to the radiation intensity that would be obtained if the power
accepted by the antenna was radiated equally in all directions (isotropically).
Antenna gain is expressed in dBi.
Radiation Pattern
A graphical representation in either polar or rectangular coordinates of the spatial
energy distribution of an antenna.
Side Lobes
The radiation lobes in any direction other than that of the main lobe.
Omni-directional Antenna
Radiates and receives equally in all directions in azimuth. The following diagram
shows the radiation pattern of an omni-directional antenna with its side lobes in
polar form.
Figure C-3: Radiation Pattern of an Omni Antenna - Side View
Figure C-4: Radiation Pattern of an Omni Antenna - Top View