2.Calculation of Transmit antenna gain
1.Antenna diameter
Diameter of parabolic reflector antenna is referred as antenna
diameter. It is denoted by ‘D’
2.Antenna efficiency
Antenna efficiency is the ratio of input power to the radiated power
of the antenna. It is denoted by ‘h’.
The value of ‘h’
lice between 0.55 to 0.73
3.Antenna gain GT
The isotropic power gain
of the antenna, GT, is defined as the power density in the maximum
direction, denoted here by PD , to the power density archived by a
100% efficient isotropic radiator.
Thus
GT=PD/(PT/4p)
PT is the total power radiated.
Antenna gain in GT = 10 log (p2D2h/(l2*100))
= 10 log (p2D2h/((C/f)2*100))
=10 log (p2D2h/((3/10*f)2*100))
=10 log (p2D2h/(3/f)2)……………(dB)………..[2]
|
Example
Calculation
of the gain of a 3.80-m parabolaidal antenna operating frequency of 6.175
G Hz & aperture
efficiency of 0.55
GT=10
log (p2D2h/(3/f)2)
Hence GT=45.21 dB
|
