ADTRAN TRACER 6000 SERIES, Руководство пользователя

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Section 2 Microwave Path Engineering Basics TRACER 6000 Series Split System Manual
18 Copyright © 2005 ADTRAN, Inc. 612806320L1-1B
Figure 1 illustrates a wireless link configuration containing all the parameters necessary for the power
budget analysis.
Figure 1. Example Microwave Path with Parameters
The following sections further discuss the power budget analysis and its components.
Antenna Gain
Actual transmit and receive antenna gain values depend strictly upon the physical characteristics of the
antennas installed for each link. In other words, the size of the dish determines the antenna gain. Using a
parabolic dish antenna results in the best performance. Antenna gains are specified in terms of decibels of
gain referenced to an isotropic source (dBi). An isotropic source is a hypothetical antenna having equal
radiation in all directions. Typical antenna gains are listed in Table 1 (standard) and Table 2 on page 19
(metric); however, dish manufacturers can provide gains for specific types of antennas.
Table 1. Antenna Gain for Given Dish Diameters (Standard)
Dish Diameter
(in feet)
Gain at 5.8 GHz
(in dBi)
2 28.5
4 34.2
6 37.5
8 40.7
10 42.5
12 44.2
G
T
G
R
d, L
P
P
T
P
R
λ
L
L