Richard Clark wrote:
The entire radiator radiates, not just portions of it. The phase,
time, distance relationships along the length contribute to a myriad
of characteristics, but they are not separable from the complete
contribution.

Using the method of moments, each segment contributes
radiation proportional to the net current in the segment.
--
73, Cecil, IEEE, OOTC, http://www.w5dxp.com