Question

What is the directivity of antenna having effective aperture 1 m^2?

(a) (frac{4pi}{lambda^2})

(b) (frac{lambda^2}{4pi})

(c) 1

(d) 4π

Answer 1

Correct option is (a) (frac{4pi}{lambda^2})

To elaborate: Directivity D=(frac{4pi}{lambda^2}A_e)

Given effective aperture Ae=1m^2

⇨ D=(frac{4pi}{lambda^2}A_e = frac{4pi}{lambda^2}  × 1 =frac{4pi}{lambda^2})