Question

For a half-wave dipole antenna, which of the following statements are right?

• A. the effective length equals its physical length
• B. the input impedance is independent of the location of the feed-point
• C. the radiation intensity is maximum along the normal to the dipole axis
• D. the current distribution along its length is uniform irresepective of the length

Answer 1

The correct option is C the radiation intensity is maximum along the normal to the dipole axis

Ans : (a)


Dipole antenna has radiation depending as $\frac{cos\left(\frac{\pi }{2}cos\theta \right)}{sin\theta }$ and maximum at ${90}^{\circ }$ to array axis.

Current distribution is uniform only for very short lengths like hertzian dipole.

$I_{eff}=\frac{2I}{\pi }for\lambda /2$ dipole

$Z_{in}$ for any wire antenna depends on loading effects from either sides of the points or length on either sides.