Radwin WinLink 1000 - Antenna Height; About the Fresnel Zone

Antenna Height Chapter 21
WinLink 1000 User Manual Release 1.9.40 21-3
Antenna Height
The recommended antenna height required for line of sight is calculated as the sum the Fres-
nel zone height and the boresight height. See About the Fresnel Zone below. Using the
notation of Figure 21-1 below, splitting ExpectedRange into d
1
+ d
2
, the Fresnel zone
height at distance d
1
from the left hand antenna, is given by
For the most conservative setting, we take the mid-point between the antennas, setting
which gives
simplifying to .
The boresight clearance height is calculated as:
where .
About the Fresnel Zone
The Fresnel zone (pronounced "frA-nel", with a silent “s”) is an elliptically shaped conical zone
of electromagnetic energy that propagates from the transmitting antenna to the receiving
antenna. It is always widest in the middle of the path between the two antennas.
0.6
300
frequency
GHz
------------------------------------ d
1
d
2

d
1
d
2
+
-----------------------------------------------------------
--

d
1
d
2
ExpectedRange
2
-----------------------------------------==
0.6
300
frequency
GHz
------------------------------------
ExpectedRange
2
-----------------------------------------
2

ExpectedRange
2
-----------------------------------------
ExpectedRange
2
-----------------------------------------+
---------------------------------------------------------------------------------------------
0.52
ExpectedRange
frequency
GHz
-----------------------------------------
R
2
Mean
ExpectedRange
2
-----------------------------------------
2
+ R
Mean
–
R
Mean
6367.4425Km=