Weak electromagnetic missiles
Abstract
It is known that the energy flux of a transient electromagnetic wave can decrease with distance more slowly than the usual inversesquare law. Such cases are referred to as electromagnetic missiles. The rate of decrease depends on the frequency spectrum of the exciting current. For a class of excitations where the frequency spectrum behaves as ‖ω‖^{}^{1}^{/}^{2}^{}^{ɛ} , the rate of decrease has been stated to be z^{2ɛ} for 0≤ɛ≤1, implying that ɛ must be less than 1 in order for the decrease to be slower than z^{}^{2}. It is shown that, in fact, the case ɛ=1 results in a dependence of z^{}^{2} ln z, i.e., an electromagnetic missile—albeit a weaker one than those previously discussed.
 Publication:

Journal of Applied Physics
 Pub Date:
 August 1990
 DOI:
 10.1063/1.347180
 Bibcode:
 1990JAP....68.1384W
 Keywords:

 Electromagnetic Fields;
 Electromagnetic Missiles;
 Electromagnetic Radiation;
 Asymptotic Properties;
 Current Distribution;
 Fourier Transformation;
 Poynting Theorem;
 Physics (General)