Page 130 - Satellite Communications, Fourth Edition

110 Chapter Four

From Eq. (4.6):

L G L S cosEl
3.133 cos50°
2.014 km
From Table 4.3, the reduction factor is

r 01 5 90
90 4L G
0.9178
For horizontal polarization, from Table 3.2 at f 12 GHz; a h 0.0188; b h 1.217
From Eq. (4.7):
b
h
A p a h R 01 L S r 01
0.0188 10 1.217 3.133 0.9178
0.891 dB

For vertical polarization, from Table 3.2 at f 12 GHz; a v 0.0168; b v 1.2
b h
A p a v R 01 L S r 01
0.0168 10 1.2 3.133 0.9178
0.766 dB

The corresponding equations for circular polarization are
a a v
h
a 5 (4.8a)
c
2
a b a b
v v
b 5 (4.8b)
h h
c
2a c
The attenuation for circular polarization is compared with that for
linear polarization in the following example.
Example 4.2 Repeat Example 4.1 for circular polarization.

Solution From Eq. (4.8a):
a c 5 a h a v
2
0.0188 0.0168

2
0.0178