# Question about current in a magnetic dipole.

1. Jul 13, 2011

### yungman

For $i(t)= I\;cos \;(\omega t - kz)\;= \Re e [Ie^{-jkz} \;e^{j\omega t}]\;= \Re e [\tilde I \;e^{j\omega t}]\;\hbox { where }\; \tilde I = I e^{-jkz}$

In the book for Hertzian dipole and miniature loop magnetic dipoles, the book assumed uniform current and provide the equation $i(t)= I \;cos \;\omega t =\Re e [I e^{j\omega t}]\;$. Is this because if current is assumed uniform, $\; \tilde I = I$, and become a constant.

So for uniform current, all phasor disappeared because there is no variation with spacial coordinates anymore?

Last edited: Jul 13, 2011