(Q). A parabolic dish provides a gain of 75dB at a frequency of 150GHz. Calculate the area of the antenna and its 3dB beamwidth.

G_dB =75dB , f = 15GHz

 λ = 3*10^8/(15*10^9) = 0.02 m

75= 10logG

G = 31622776.6

Now,

Capture Area = Directivity(G)*  λ^2/4π

A_e = 1007.09 m²

G_p = 6D² / λ^2

D = √(G_p /6)* λ

D = √ (31622776.6/6)*0.02

D = 45.9 m

BWFN = 140 λ /D

= 140*0.02/45.9

= 0.06^O