Question

For AUT to encounter uniform illumination which of the following is true?

(a) Height of AUT should be equal to or more than four times the dimension of antenna

(b) Height of AUT should be less than four times the dimension of antenna

(c) Height of AUT should be equal to or more than two times the dimension of antenna

(d) Height of AUT should be less than two times the dimension of antenna

I had been asked this question by my school principal while I was bunking the class.

Origin of the question is Antenna Ranges topic in chapter Modern Antennas & Antenna Measurements of Antennas

Answer 1

Correct answer is (a) Height of AUT should be equal to or more than four times the dimension of antenna

For explanation I would say: The amplitude variation over AUT should be more than 0.2dB to get AUT encounter uniform illumination. To satisfy that the height criteria of AUT should be equal to or more than four times the dimension of antenna.