Question

Find the effective area of a half-wave dipole operating at frequency 100MHz and directive gain 1.8?

(a) 1.28m^2

(b) 2.18m^2

(c) 0.128m^2

(d) 12.8m^2

This question was addressed to me in an internship interview.

This is a very interesting question from Antenna Characteristics in portion Antenna Parameters of Antennas

Answer 1

The correct option is (a) 1.28m^2

The explanation: The effective area \(A_e=\frac{\lambda^2}{4π}D \)

\(\lambda = \frac{c}{f}=3×\frac{10^8}{100×10^6}=3m\)

\(A_e=\frac{3^2}{4π}×1.8=1.28m^2\)