Question

What is the beam width for a half wave dipole antenna?

(a) 90°

(b) 180°

(c) 50°

(d) 250°

I have been asked this question by my college director while I was bunking the class.

This intriguing question originated from Types of Antenna topic in chapter Antennas and Wave Propagation of Avionics

Answer 1

Correct option is (a) 90°

For explanation I would say: The beam width is measured between the points on the radiation curve that are 3 dB down from the maximum amplitude of the curve. The maximum amplitude of the pattern occurs at 0° and 180°. The 3-dB down points are 70.7 percent of the maximum. The angle formed with two lines extending from the center of the curve to these 3-dB points is the beam width. The beam width is 90°. The smaller the beam width angle, the more directional the antenna.