Fundamentals of Engineering Electromagnetics 1st Edition by David Cheng

Exercise 27

In dealing with thin linear antennas, it is sometimes convenient to define an effective length, e , of the antenna, which is the current moment normalized with respect to the current at the feed point. For a center-fed dipole of half-length h , the maximum effective length (at = /2) is
(10-85)
Determine the effective length of
a) a Hertzian dipole of length d ,
b) a half-wave dipole with sinusoidal current distribution I 0 cos z , and
c) a half-wave dipole with triangular current distribution I 0 (1 4| z |/ ).