Question

Two dissimilar antennas having their maximum directivities equal

(a) Must have their beam widths also equal

(b) Cannot have their beam widths equal because they are dissimilar antennas

(c) May not necessarily have their maximum power gains equal

(d) Must have their effective aperture areas (capture areas) also equal

Answer 1

THE CORRECT OPTION IS (C)

Explanation:

η= Radiated Power/Input power = R_rad/R_rad+R_loss

Efficiency is also given as

η=Power gain/Directive gain = g_p/g_d

Radiation resistance of two antennas may be different hence efficiency may not be same. This indicates power gains may not be same