User Manual

Section 2, Microwave Path Engineering Basics TRACER 4205 System Manual
16 © 2002 ADTRAN, Inc. 612804205L1-1A
5. PATH LOSS
The expression
where
f carrier frequency (Hz)
λ carrier wavelength (c / f) (meters)
d path distance (meters)
c speed of light, free-space (meters)
is called the path loss, and increases rapidly as either path length increases or carrier wavelength decreases
(which happens as the carrier frequency increases). So, longer microwave paths will naturally experience
more path loss than shorter paths. Likewise, higher frequency microwave communication will experience
more path loss than lower frequency microwave communication.
Table 1 tabulates path loss values for various path lengths for the TRACER 4205 system. Values not listed
in the table can be interpolated from those listed.
Table 2. Path Loss for Given Path Lengths
Path Length
(miles)
Path Loss
(dB)
1112
2118
3 121
4 124
5 126
6 127
7 129
8 130
9 131
10 132
11 133
12 133
13 134
14 135
15 135
16 136
17 136
18 137
19 137
L
P
4πd
λ
----------


2
4πdf
c
------------


2
==
(dB)