Question

As the aperture area of an antenna increases, its gain _________.

• A. increases
• B. decreases
• C. remain steady
• D. behaves unpredictably

Hint:

Larger antennas (bigger aperture) mean more gain—especially useful in satellite and radar systems.

Answer 1

The Correct Option is A

Antenna gain is directly related to its physical size, particularly its effective aperture area. In simple terms, larger antennas can capture more electromagnetic energy from a wavefront, thus providing better directionality and gain. \[ G = \frac{4\pi A_e}{\lambda^2} \] Where:
\(G\) = antenna gain
\(A_e\) = effective aperture area
\(\lambda\) = wavelength
Implication:
Larger \(A_e\) leads to higher gain for the same frequency.
This improves signal reception and transmission, especially for parabolic dish and horn antennas.
Incorrect Options:
(2): Gain increases, not decreases.
(3): It does not stay steady; it scales with area.
(4): The relation is predictable by the above formula.
Final Answer: (1) increases