A rigorous method-of-moments (MoM) analysis is used to model wide-band scattering from general three-dimensional perfectly conducting objects buried in a lossy layered medium. Here, we focus on ordnance buried in a half space (soil). The time-domain fields scattered from a tilted antitank mine are examined in detail as a function of polarization and observation position.

Computational aspects of EM pulse propagation along the nonuniform earth surface are considered. For ultrawide-band pulses without carrier, the exact wave equation in a narrow vicinity of the wave front is reduced to a time-domain version of the LeontovichFock parabolic equation. To solve it by finite differences, we introduce a time-domain analog of the impedance BC and a nonlocal BC of transp...

The notion of representing discrete-time electromagnetic pulse (EMP) signals using or-thonormal Laguerre sequences is introduced. The motivation for doing so is that EMP signals and Laguerre sequences are both characterized by decaying exponentials. It is shown that very eecient Laguerre representation of EMP signals is possible using this approach. Given a sequence x(n), its Laguerre expansion...

Maxwell’s equations are cast in the form of the Schrödinger equation. The Lanczos propagation method is used in combination with the fast Fourier pseudospectral method to solve the initial value problem. As a result, a time-domain, unconditionally stable, and highly efficient numerical algorithm is obtained for the propagation and scattering of broad-band electromagnetic pulses in dispersive an...

It is well known that optical media create artificial geometry for light, and curved geometry acts as an effective optical medium. This correspondence originates from the form invariance of Maxwell's equations, which recently has spawned a booming field called 'transformation optics'. Here we investigate responses of three transformation media under electromagnetic pulses, and find that pulse r...

INTRODUCTION The rapid growth of wireless communication technologies has caused public concerns regarding the biological effects of electromagnetic radiations on human health. Some early reports indicated a wide variety of non-thermal effects of electromagnetic radiation on amphibians such as the alterations of the pattern of muscle extractions. This study is aimed at investigating the effects ...

A novel approach to photonic generation of phase-coded microwave signals based on optical pulse shaping and time delay is proposed. In the proposed approach, an optical short pulse train is inserted with a specified amount of time-delay to certain pulses, and then converted into super-Gaussian microwave pulses based on the optical pulse shaping technique. By properly adjusting the time-delay, p...

A novel short-pulse concept (SLIM) suited to a new generation of a high gradient induction particle accelerators is described herein. It applies advanced solid state semiconductor technology and modern microfabrication techniques to a coreless induction method of charged particle acceleration first proven on a macro scale in the 1960’s. Because this approach avoids use of magnetic materials the...

We report the first experimental demonstration of time-reversal focusing with electromagnetic waves. An antenna transmits a 1-micros electromagnetic pulse at a central frequency of 2.45 GHz in a high-Q cavity. Another antenna records the strongly reverberated signal. The time-reversed wave is built and transmitted back by the same antenna acting now as a time-reversal mirror. The wave is found ...

[1] Recent observations of terrestrial gamma-ray flashes (TGFs) (Smith et al., 2005) suggest the need for a new mechanism of TGF production. Consideration of relativistic runaway electron (RRE) avalanche driven by electromagnetic impulses (EMP) radiated by rapidly moving lightning return strokes indicates that TGFs can be produced by discharges with peak return stroke currents Ip > 450–700 kA w...