Planning wireless systems
105542_en_05 PHOENIX CONTACT 145 / 198
Figure 8-16 Fresnel zone
General formula for calculating the diameter of the Fresnel zone:
r = radius of the Fresnel zone
= wavelength (0.125 m for 2.4 GHz, 0.345 m for 868 MHz)
d = distance between the antennas in m
Radius of the Fresnel zone for 2.4 GHz and d = 3000 m:
r = 9.68 m
Result: the radius of the Fresnel zone is 9.68 m at a wavelength of 0.125 m (2.4 GHz) and
a distance of 3000 m between the antennas.
Table 8-8 Radius of the Fresnel zone depending on the distance
Wireless path distance
(d)
Radius of the Fresnel
zone (r) for 2.4 GHz
Radius of the Fresnel
zone (r) for 868 MHz
200 m 1.5 m 4.2 m
500m 4m 6.6m
1000 m 5 m 9.3 m
2000 m 8 m 13.1 m
4000 m 11 m 18.6 m
5000 m - 20.8 m
10 km - 24.4 m
15 km - 36 m
20 km - 41.5 m
25 km - 46 m
To Next Page
Loading...
