User manual

gitudinal axis. At least 60 % of the 1st Fresnel zone must remain free of obstacles. The ra-
dius (or the small semi-axis) depends on the frequency used and the distance between the
antennas.
Fig. 80: 1. Fresnel zone
Example: Radius of 1st Fresnel zone as a function of distance from transmit antenna for
antenna separation of 5 km at 2.45 GHz.
Example 1
Distance from transmit an-
tenna (km)
Radius of 1st Fresnel zone
(m)
Radius at 60 % of
1st Fresnel zone (m)
0,250 5,4 4,2
0,500 7,4 5,7
0,750 8,8 6,8
1,000 9,9 7,7
1,250 10,7 8,3
1,500 11,3 8,8
1,750 11,8 9,1
2,000 12,1 9,4
2,250 12,3 9,5
2,500 12,4 9,6
2,750 12,3 9,5
3,000 12,1 9,4
3,250 11,8 9,1
3,500 11,3 8,8
3,750 10,7 8,3
4,000 9,9 7,7
4,250 8,8 6,8
Teldat GmbH
10 Wireless LAN
bintec WLAN and Industrial WLAN 181