Correct Answer - Option 1 : 39 dB
Concept:
The efficiency of dish antenna is given by:
\(Gain \ = \ \frac{η \ 4 \ \pi \ A_e}{λ^2}\) ---(1)
Where,
η = efficiency
Ae = Area of parabolic antenna
λ = Wavelength
Calculation:
η = 80 %
ν = 9.5 GHz
D = 1 m
As c = νλ
\(\lambda=\frac{3 \ \times \ 10^8}{9.5 \ \times \ 10^9}=0.0315\)
\(A_e=\frac{\pi \ D^2}{4}=\frac{\pi}{4}\)
Putting all values in equation (1)
\(Gain = \frac{0.80 \ \times 4\pi^2}{4 \ (0.0315)^2}=7912.62\)
Gain in db = 10log10(7917.62) = 39 db.
1. The parabolic reflector antenna is also known as the satellite dish antenna.
2. They have very high gain, bandwidth, and low cross-polarization.
3. They operate in the VHF region of frequency range from 30 - 300 MHz
