A generalized antenna theorem for broadband pulses
Abstract
Using a very general argument, one can place an upper limit on the fluence that can be delivered to a distant point by passing a pulse with finite energy through an aperture of finite area. Based on a timedependent form of Huygen's principle, shown is the maximum possible fluence produced by an arbitrary scalar field passing through an aperture to an observation point is about equal to the fluence produced by a nearly monochromatic pulse of the same energy. This fictitious pulse uniformly illuminates the aperture and converges to a geometric focal spot at the observation point. The frequency of the monochromatic wave is made equal to the apertureaveraged rootmeansquare frequency of the actual diffracting field. Thus, a pulse with arbitrary time dependence satisfies an antenna theorem very similar to the more wellknown version of the theorem satisfied by monochromatic waves.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 March 1989
 Bibcode:
 1989STIN...8925373J
 Keywords:

 Antenna Design;
 Electromagnetic Pulses;
 Fluence;
 Huygens Principle;
 Broadband;
 Rayleigh Scattering;
 Communications and Radar