What happens to the beamwidth of an antenna as the gain is increased?

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Multiple Choice

What happens to the beamwidth of an antenna as the gain is increased?

Higher gain means the antenna concentrates more of its radiated energy into a narrower direction. Gain is a measure of how much power is directed in the main lobe compared to in all directions; when that energy is focused more tightly, the main beam becomes narrower. A practical way to see this is with a dish or other highly directional antenna: as the dish size (and thus gain) increases, the beam narrows. For a circular aperture, the approximate relation shows beamwidth shrinking as the aperture (and thus gain) grows. So increasing gain makes the beamwidth decrease.

Higher gain means the antenna concentrates more of its radiated energy into a narrower direction. Gain is a measure of how much power is directed in the main lobe compared to in all directions; when that energy is focused more tightly, the main beam becomes narrower. A practical way to see this is with a dish or other highly directional antenna: as the dish size (and thus gain) increases, the beam narrows. For a circular aperture, the approximate relation shows beamwidth shrinking as the aperture (and thus gain) grows. So increasing gain makes the beamwidth decrease.

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