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

A_{e} = 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 = 10log**_{10}(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