Fresnel Zone Diameters
Range
Distance
Required Fresnel Zone Diameter (900
MHz Radios)
Required Fresnel Zone Diameter (2.4
GHz Radios)
1000 ft. (300
m)
16 ft. (7 m)
11 ft. (5.4 m)
1 mile (1.6 km)
32 ft. (12 m)
21 ft. (8.4 m)
In order to have ground clearance, the combined antenna height should be equal to the diameter of the
Fresnel Zone.
Increased Antenna Gain
Transmitting and receiving antennas are used to focus and direct radio waves in specific directions.
Antennas are another component that can be adjusted to increase the distance data can travel in a wireless-
communication system. Antenna gain is an important variable that can be adjusted in order to increase
range. Antenna gain describes the amount of focus the antenna is able to apply to the system by directing the
energy. The more focus the antenna can apply, the more range the system will yield. High-gain antennas can
achieve greater range than low-gain antennas, though they cover less area.
Omni-directional antennas focus energy evenly in a doughnut-shape around the antenna.
Gain vs. Vertical Beam Width (VBW)
l
2.1 dBi (0 dBd) = 75º VBW
l
5.1 dBi (3 dBd) = 33º VBW
l
8.1 dBi (6 dBd) = 17º VBW
Directional antennas focus energy more specifically in one direction.
Gain vs. Vertical Beam Width (VBW)
l
8.1 dBi (6 dBd) = 70º VBW
l
11.1 dBi (9 dBd) = 55º VBW
l
15.1 dBi (13 dBd) = 35º VBW
Doc. No.: M00-20-7074 Rev.: 6
Page 10 of 43
Содержание M00-20-7074
Страница 22: ...7 Select the discovered modem s 8 Select Add selected devices Doc No M00 20 7074 Rev 6 Page 22 of 43...
Страница 23: ...9 Click the Radio Module on the left to verify configure Doc No M00 20 7074 Rev 6 Page 23 of 43...
Страница 32: ...c Wait for the modem s to be detected 7 Select the discovered modem s Doc No M00 20 7074 Rev 6 Page 32 of 43...
Страница 36: ...3 Select the discovered modem s 4 Select Add selected devices Doc No M00 20 7074 Rev 6 Page 36 of 43...
Страница 43: ......
