Which statement describes the power requirement when using a directional antenna?

Which statement describes the power requirement when using a directional antenna?

• A. It requires less power to achieve the same range.
• B. It requires more power to achieve the same range.
• C. It reduces antenna gain.
• D. It increases detection signature.

Answer: (A)

When you use a directional antenna, you get higher gain in the direction you’re aiming. That means the signal is more strongly directed toward the target, so for the same range you don’t have to put in as much transmitter power. The antenna’s gain effectively boosts the in-direction signal, letting you achieve the same reach with less power. For example, a directional antenna with gain in the desired direction can deliver the needed received signal strength with a smaller transmit power than an isotropic radiator. The other ideas don’t describe this relationship: the point isn’t that you reduce or increase the antenna gain itself, but that its higher gain in a specific direction lowers the power you need to reach the same distance.

When you use a directional antenna, you get higher gain in the direction you’re aiming. That means the signal is more strongly directed toward the target, so for the same range you don’t have to put in as much transmitter power. The antenna’s gain effectively boosts the in-direction signal, letting you achieve the same reach with less power. For example, a directional antenna with gain in the desired direction can deliver the needed received signal strength with a smaller transmit power than an isotropic radiator. The other ideas don’t describe this relationship: the point isn’t that you reduce or increase the antenna gain itself, but that its higher gain in a specific direction lowers the power you need to reach the same distance.