The internally stored electric energy (Q-energy) of a disk monopole antenna increases as compared to a monopole antenna without a top disk.Recently it was shown that the Q-energy can be significantly reduced and the bandwidth increased by shielding the disk monopole antenna using a thin magnetic material.In the present paper we consider the same structure to explain another method johnny cash style clothing to increase the bandwidth by using a shield made of dispersive magnetic material.
We apply the Kramers-Kronig transforms to derive physically correct real and imaginary parts of the dispersive magnetic material.We do read more not aim at a reduction of the internal energy but at a compensation of the electric by a magnetic stored energy for a wide frequency range.Disk monopole antennas with shells consisting of such dispersive permeability are finally numerically evaluated by means of a commercial frequency-domain field simulator.