Question

Directive gain of antenna when radiation intensity is 5W/Steradian and radiated power 5W is ____

(a) 4π

(b) 1/4π

(c) 25

(d) 1

Answer 1

The correct option is (a) 4π

To elaborate: Given Ud(θ,∅) = 5W/steradian , Pr=5W

Directive gain (G_d=frac{P_{d( heta,emptyset)^{r^2}}}{P_r/4pi} = frac{U_{d( heta,emptyset)}}{P_r/4pi}=4pi)