Balluff BIS U Basishandbuch Seite 41

BIS U Basic Manual
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Reference Antennas and Antenna Parameters
4.2 Antenna Gain Real antennas bundle radiation and therefore generate maximum radiated power density in one
direction (main dispersion direction).
Antenna gain must be used to make antennas with different designs or directional characteristics
comparable and to define a dimension to indicate the intensity of radiated antenna power aimed
in a preferred direction. The antenna gain represents the factor by which power radiated in the
main dispersion direction is higher than a reference antenna.
It is standard to indicate the gain of a real antenna in relation to an isotropic radiator.
Figure 4 shows that radiation is also bundled for the half-wave dipole. The antenna gain based
on an isotropic radiator is:
4.3 Return Loss and
The voltage standing wave ratio (VSWR) and the return loss (RL) indicate how much of the
Voltage Standing energy flowing through the cable to the antenna is reflected to the receiving antenna input on the
Wave Ratio
processor unit. A poor VSWR value can cause interference or noise.
A typical value < 1.2 to 1 is specified for the BIS U 302 antenna.
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G[dBi]
Linear gain based on an isotropic radiator
G[dBic]
Circular gain based on an isotropic radiator
G[dBi] = 2.15 dBi
half-wave dipole
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