Nearfield structure of impulse driven, tubular, thick dipoles

The impedance behaviour of electrical dipoles can be well described by the model of R. Sato and M. Sato (1984). It uses a transmission line section with load sections located at either termination. Each load contains lumped elements. i.e. inductance and resistors, thus describing the effects of the feeding region and the dipole tip on the current. The time dependant nearfields of thick tubular dipoles, given for the cases of a voltage impressed impulse generator and of a high impedance generator, are compared with these of more idealized (thinner) dipoles. From a two wire model the effects of thickness are explained and partly related to an equivalent circuit. It is shown, that the assumption, that radiation is provoked only by the feeding point and the dipole tips is not valid for thick dipoles