Basic dipole concepts

The first paragraph focuses on the physical analysis of the radiation generated by the elementary electric dipole, followed by a brief study of the magnetic dipole, which is simply the dual form of the former. An elementary electric dipole can be presented in two equivalent models. One considers two electric charges + q and - q spaced apart by the rigid distance Δl, with which is associated the electric moment p determined by the product, p = q Δl. The second model assumes that + q and - q evolve with the time variable t according to the analytical function q (t), the elementary electric dipole can then be likened to a filiform conductor of dimension Δl flowing the current i (t), the result of the direct application of Coulomb's law,

...