Question

Relation between directivity and effective area of transmitting and receiving antenna is ________

(a) Dt At=Dr Ar

(b) Dt Ar=Dr At

(c) At Dt=∈Dr Ar

(d) Dt At=∈Dr Ar

This question was addressed to me in an online interview.

This key question is from Basics topic in chapter Antenna Parameters of Antennas

Answer 1

Right option is (b) Dt Ar=Dr At

Easiest explanation: The power collected by the receiving antenna is

\(P_r = \frac{P_tD_tA_r}{4\pi R^2} => D_tA_r = \frac{P_r}{P_t}4\pi R^2\) = Dr At

∴ Dt Ar=Dr At