When the antenna diameter is doubled, the gain of the antenna
- A. Reduces by half
- B. Increases by 3 dB
- C. Reduces by 3 dB
- D. Increases by 6 dB
Answer: D. Increases by 6 dB
Explanation: Antenna gain is proportional to the square of the diameter ($G \propto D²$). Doubling the diameter increases the gain by a factor of 4. In decibels, $10\log_{10}(4) \approx 6\text{ dB}$.