| Investigation of ELF Signals Associated with Mine Warfare: A University of Idaho and Acoustic Research Detachment Collaboration |
30-Jun-2009 |
69 pages |
| Authors:
Dennis Sullivan; Jeffrey L Young; Robert G Olsen; Christopher L Wagner; IDAHO UNIV MOSCOW
|
 | The questions that are being asked in this investigation are: (1) once an ELF signal is generated, how far does it propagate and still be detectable and (2) how can such signals be modeled, excited and measured? To this end, the scenario considered is one in which an ELF source of the electric or magnetic kind is located in or above water, such as a lake or ocean. This source ... |
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| Analysis of Plasma Communication Schemes for Hypersonic Vehicles: Final Report |
Feb-2009 |
71 pages |
| Authors:
David V Rose; Carsten H Thoma; Vladimir Sotnikov; VOSS SCIENTIFIC LLC ALBUQUERQUE NM
|
| We summarize progress in our analysis of proposed communication schemes for hypersonic vehicles in flight. Investigations into the electron-acoustic wave (EAW) communication scheme have yielded a dispersion analysis indicating that EAW modes can be generated and propagate in the plasma layer. Furthermore, we have demonstrated that these modes can be coupled to EM waves at the plasma layer boundary for the assumption of a sharp density boundary. We discuss results ... |
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| Reverberant Microwave Propagation |
Oct-2008 |
246 pages |
| Authors:
Robert E Richardson; NAVAL SURFACE WARFARE CENTER DAHLGREN DIV VA
|
| The purposes of this Reverberant Microwave Propagation work were, first, to expand measurement capabilities by an extensive investigation of short pulse excitation of empty, partially filled, and coupled cavities, and second, to improve our understanding of microwave propagation in moderately reverberant spaces, such as ship and aircraft compartments and in metal buildings. Understanding propagation in these types of spaces is increasingly important to the U.S. Navy. Various electromagnetic compatibility (EMC) ... |
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| Terahertz Plasmon-Induced Conductance Effects in Semiconductor Heterostructures |
05-Sep-2008 |
27 pages |
| Authors:
Robert E Peale; UNIVERSITY OF CENTRAL FLORIDA ORLANDO
|
| Experimental investigation of the coupling of free space radiation to surface plasmons by silver or Pd2Si gratings was performed for different grating profiles at CO2 laser wavelengths. Comparison of the results with the theory of Hessel and Liner 1965 and of Wheeler, Arakawa, and Ritchie 1976 suggests that the former gives the more accurate description in the long-wave IR. For that theory, the comparison gives an empirical non-linear relation between ... |
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| Ionospheric Response to Solar Flares Using an Improved Version of SAMI2 |
MAR 2008 |
102 pages |
| Authors:
III Reich Joseph P.; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT/DEPT OF ENGINEERING PHYSICS
|
| Solar flare-induced disturbances in the ionosphere can affect the propagation of electromagnetic waves, causing errors in GPS navigation, false radar echoes, and loss of HF radio communications. Accurately modeling the ionospheric response to flares is the first step in predicting, and eventually mitigating their effects. Sami2 is Another Model of the Ionosphere (SAMI2) is a 2-D ionospheric model, which, in its standard form, is ill-suited for studying solar flare effects ... |
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| Low-Cost Production of Photonic Bandgap Materials Through Bubbling |
SEP 2007 |
38 pages |
| Authors:
Daniel J. O'Brien; Eric D. Wetzel; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Photonic bandgap materials (PBGMs) prevent the propagation of electromagnetic waves across certain wavelengths the so-called bandgap. This behavior is the result of periodic variations in the material's dielectric constant, with the location of the bandgap as a function of the spacing between dielectric features. PBGMs show great promise in optoelectronics as waveguides and in sensors. Unfortunately, the large-scale production of PBGMs is difficult. This report proposes a simple low-cost method ... |
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| A Smart Climatology of Evaporation Duct Height and Surface Radar Propagation in the Indian Ocean |
SEP 2007 |
159 pages |
| Authors:
Katherine L. Twigg; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Surface electromagnetic propagation over the ocean is highly sensitive to near-surface atmospheric variability, particularly the height of the evaporation duct. Seasonal variation in near-surface metrological factors and sea surface temperatures impact the evaporation duct height (EDH). Present U.S. Navy EDH climatology is based on sparse ship observations over a relatively short time period and an outdated evaporation duct (ED) model. This EDH climatology does not utilize smart, or modern, climatology ... |
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| A Research Program on the Asymptotic Description of Electromagnetic Pulse Propagation in Spatially Inhomogeneous, Temporally Dispersive, Attenuative Media |
SEP 2007 |
8 pages |
| Authors:
Kurt E. Oughstun; Natalie A. Cartwright; VERMONT UNIV BURLINGTON COLL OF ENGINEERING AND MATHEMATICS
|
| The high frequency, low power characteristics of ultrawideband/short-pulse signals exhibit uniquely promising features with applications to remote sensing of terrestrial objects from satellites, foliage-penetrating radar, as well as the study of biological tissue exposed to ultrawideband pulses. Indeed, previous studies of ultrawideband electromagnetic pulse propagation through dispersive, nonconducting media has shown the existence of a so-called Brillouin precursor whose peak amplitude only decays algebraically with propagation distance. However, materials such ... |
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| Simulation of Radiowave Propagation in a Dense Urban Environment |
MAR 2007 |
65 pages |
| Authors:
Chris V. Chung; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| One objective of this thesis was to investigate the effect of details, such as the windows of high-rise buildings, on the radio wave propagation in the dense urban environment through modeling and simulations. If adding windows does not significantly change the signal distribution on average, it may not be necessary to build such a detailed model. Simulations are performed using several levels of detail and the results compared to estimate ... |
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| Advanced Propagation Model (APM) Version 2.1.04 Computer Software Configuration Item (CSCI) Documents |
FEB 2007 |
439 pages |
| Authors:
A. E. Barrios; W. L. Patterson; R. A. Sprague; SPACE AND NAVAL WARFARE SYSTEMS COMMAND SAN DIEGO CA
|
| This document provides Version 2.1.04 Computer Software Configuration Item documents for the Advanced Propagation Model (APM). The APM calculates range-dependent electromagnetic system propagation loss and propagation factor within a heterogeneous atmospheric medium over variable terrain, where the radio-frequency index of refraction is allowed to vary vertically and horizontally. The first document specifies the functional requirements that are to be met by the APM CSCI. A discussion of the input software ... |
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| Classical Method for Deriving the Electromagnetic Propagation Equations for Double Negative Materials With Application for Antenna Design |
FEB 2007 |
28 pages |
| Authors:
Ira Kohlberg; KOHLBERG ASSOCIATES INC RESTON VA
|
| We derive a system of propagation equations in a Double Negative (DN) material in a way that appears to differ from previous derivations although the end result is the same. Our derivation assumes the Poynting vector theorem applies, real materials always have some loss, epsilon(omega) and mu(omega) are obtained from real materials, and wave energy traveling in a specified direction must always be accompanied by a loss of energy in ... |
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| Mesoscale Forecast Analysis of Atmospheric Boundary Layer Structure and Electromagnetic Signal Attenuation During the Terrain-Induced Rotor Experiment (T-REX) |
NOV 2006 |
27 pages |
| Authors:
E. Colon; R. E. Dumais; T. Henmi; R. Flanigan; NETWORK COMPUTING SERVICES INC ADELPHI MD ARMY HIGH PERFORMANCE RESEARCH CENTER
|
| With the increased importance of high bandwidth microwave communication and remote sensing capabilities in Army battlefield operations, the need arises in being able to quantify the impact of microwave signal attenuation sources such as turbulence-driven fluctuations in the atmospheric refractive index and gaseous absorption. An assessment of attenuation effects in the atmospheric boundary layer was afforded by the Terrain-Induced Rotor Experiment (T-REX), which was a large-scale, observational study involving participants ... |
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| Numerical Solution of the Extended Nonlinear Schrodinger Equation |
SEP 2006 |
199 pages |
| Authors:
John V. Harvey; JR Medina Richard L.; L3 COMMUNICATIONS TITAN CORP SAN ANTONIO TX
|
| High-resolution mathematical models of the extended nonlinear Schroedinger equation have been designed which include diffraction combined with non-zero second-order group-velocity dispersion (GVD). These models follow a Gaussian pulse as it propagates in air to a large distance (several meters). With diffraction disabled, a pulse quickly collapses to a single singularity on the propagation axis. Alternatively, with diffraction included, a pulse will collapse into a pair of fins off the propagation ... |
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| Radio Propagation Prediction Software for Complex Mixed Path Physical Channels |
14 AUG 2006 |
91 pages |
| Authors:
Stephen A. Fast; REMCOM INC STATE COLLEGE PA
|
| It has become increasingly clear that the customers for the Mixed Path project desire API to the various Wireless InSite calculation engines. Thus the WI engines can be incorporated into tools such as OPNET and QualNet for network analysis or into various signal processing software. For network analysis all that is required is an extremely fast computing propagation model that captures the mixed path propagation at an acceptable resolution and ... |
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| 3D Photonic Crystals Build Up By Self-Organization Of Nanospheres |
23 MAY 2006 |
23 pages |
| Authors:
Yu-Wen Chen; NATIONAL CENTRAL UNIV CHUNG-LI (TAIWAN) DEPT OF CHEMICAL AND MATERIAL ENGINEERING
|
| Band gap structure is the most important information while studying electromagnetic propagation in photonic crystals. A collection of free software is used to set up an analysis tool system for simulation purpose. Because it is desired for application and has been a technique challenge to fabricate a photonic crystal possessing a complete photonic band gap operates at the optical wavelength regime, we study how to optimize the size and position ... |
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| Measurement of the Propagation Constant of Surface Waves on a Periodic Array (Preprint) |
MAY 2006 |
6 pages |
| Authors:
Dan S. Janning; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH SENSORS DIRECTORATE
|
| A technique is proposed to measure the propagation constant of surface waves on a periodic dipole array using a waveguide simulator. Due to the slow wave characteristic of surface waves, it is necessary to present an evanescent waveguide mode to the plane containing the elements. Two techniques for sensing the element currents are outlined. |
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| High-Frequency Electromagnetic Propagation/Scattering Codes |
31 DEC 2005 |
160 pages |
| Authors:
MONOPOLE RESEARCH THOUSAND OAKS CA
|
| The objective of our effort was to develop computational methods for constructing high-frequency asymptotic solutions in scattering on perfectly conducting objects. The emphasis of the first stage of our work was to describe high frequency phenomena in terms of numerically implemented evolution of wavefronts associated with the propagating waves. The wavefront evolution algorithm is implemented for the leading high frequency mechanisms including: free-space propagation, reflection on smooth surfaces, wave-front splitting ... |
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| The Microwave Behavior of an Anisotropic Negative Index Medium |
24 OCT 2005 |
11 pages |
| Authors:
J. S. Derov; B. W. Turchinetz; E. E. Crisman; A. J. Drehman; S. R. Best; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE
|
| Free space microwave measurements are reported for a split ring and post type metamaterial which exhibits negative refraction in a frequency band between 13.5 and 14.5 GHz. Varying azimuthal angles and magnitudes are achieved by changing the polarization of the transmitter and receiver relative to each other and to the anisotropic axes of the material. The amplitude of the cross-polarized transmission has been measured at 50% of the co-polarization level. ... |
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| Measured Polarization Response of Negative Index Metamaterial |
12 OCT 2005 |
5 pages |
| Authors:
J. S. Derov; B. W. Turchinetz; E. E. Crisman; A. J. Drehman; S. R. Best; AIR FORCE RESEARCH LAB HANSCOM AFB MA SENSORS DIRECTORATE
|
| The geometrical anisotropy and bi-anisotropy of a split ring and post type metamaterial is studied by free space microwave measurements in a frequency band near 13.5 GHz where it exhibits negative index of refraction. The orientation of the linearly polarized incident wave determines whether the refracted response is negative or positive. Measurements of cross polarization through the prism are 50% of the co-polarization. The insertion loss through the material of ... |
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| Electromagnetic Wave Propagation Scheme |
10 AUG 2005 |
16 pages |
| Authors:
Anthony B. Bruno; NAVAL UNDERSEA WARFARE CENTER DIV NEWPORT RI
|
| An apparatus for effecting propagation of electromagnetic waves, comprising a hull outer surface, a dielectric material disposed over the hull outer surface, and an electrically conductive member embedded within the dielectric material. When a liquid medium contacts the dielectric material, the liquid medium, the hull outer surface, the dielectric material and the electrically conductive member cooperate to provide a waveguide through which electromagnetic waves can propagate wherein the boundaries of ... |
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| Evaluation of Quasi-Linear Diffusion Coefficients for Whistler Mode Waves in a Plasma with Arbitrary Density Ratio |
22 MAR 2005 |
13 pages |
| Authors:
J. M. Albert; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE WEATHER CENTER OF EXCELLENCE
|
| Techniques are presented for efficiently evaluating quasi-linear diffusion coefficients for whistler mode waves propagating according to the full cold plasma index of refraction. In particular, the density ratio omega (sub pe)/Omega(sub e) can be small, which favors energy diffusion. This generalizes an approach, previously used for high-density hiss and electromagnetic ion cyclotron waves, of identifying (and omitting) ranges of wavenormal angle Theta that are incompatible with cyclotron resonant frequencies omega ... |
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| A New Estimator for Directional Properties of Nearshore Waves |
04-Jan-2005 |
12 pages |
| Authors:
R T Guza; T H Herbers; A Sheremet; LOUISIANA STATE UNIV BATON ROUGE COASTAL STUDIES INST
|
| The infragravity wave (periods between roughly 20 and 200 s) energy balance in shallow, nearshore waters is believed to be effected by generation by groups of sea and swell, dissipation, shoreline reflection, and refractive trapping. Observations obtained with alongshore oriented arrays of current meters or pressure gauges have been previously used to identify concentrations of energy at the frequency-alongshore wavenumbers of refractively trapped edge waves, but seaward and shoreward propagating ... |
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| Characterization of Meta-Materials Using Computational Electromagnetic Methods |
JAN 2005 |
5 pages |
| Authors:
Manohar Deshpande; Joon Shin; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CENTER
|
| An efficient and powerful computational method is presented to characterize a meta-material in terms of its specified electromagnetic properties. Using the periodicity of meta-materials, the Finite Element Methodology (FEM) is developed to estimate reflection and transmission through the meta-material structure for a normal plane wave incidence. For efficient computations of reflection and transmission through a meta-material over a wideband frequency range, a Finite Difference Time Domain (FDTD) approach is developed. ... |
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| FDTD Analysis of a New Leaky Traveling Wave Antenna |
2005 |
5 pages |
| Authors:
G. M. Zelinski; M. L. Hastriter; M. J. Havrilla; J. S. Radcliffe; A. J. Terzuoli; G. A. Thiele; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
|
| A new antenna is proposed based on a structure first constructed by Menzel that utilizes the leaky wave phenomena of the first higher order mode. This work seeks to determine the effect on performance of the antenna due to varying geometries. Standard antenna range far-field and near-field measurements are not sensitive enough to extract the propagation constant. A numerical simulation was thus developed using the Finite Difference Time Domain (FDTD) ... |
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| Improvement of an Acoustic Sounder Device Used to Measure Atmospheric Turbulence |
DEC 2004 |
71 pages |
| Authors:
Jeng-Shiung Liu; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Optical turbulence plays an important role in the propagation of electromagnetic waves through the atmosphere because it broadens and distorts the optical beam. A variety of optical, thermal, and acoustic instruments are used to detect the atmospheric turbulence and an acoustic echosounder has proven to be a valuable tool to probe the fine dynamic structure of atmospheric turbulence within first hundred meters above the surface. The first planar acoustic echosounder ... |
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| Numerical Modelling of Electromagnetic Wave Propagation and Scattering: High-Order Schemes, Impedance Boundary Conditions and Cole-Cole Dielectrics |
12 SEP 2004 |
19 pages |
| Authors:
Peter G. Petropoulos; NEW JERSEY INST OF TECH NEWARK DEPT OFMATHEMATICS
|
| Paper #1 was listed in the report for Grant F49620-99-1-0072 as "to appear" and the work presented there was described previously. In paper #2 we presented an analysis of the perfectly matched layer in cylindrical coordinates discretized with a staggered second-order accurate finite difference time domain method. In paper #3 we conclusively addressed the long-standing issue of the long-time stability of the unsplit Perfectly Matched Layer. In paper #4 we ... |
|
| Stability and Transient Effects in Ultraviolet Filaments |
SEP 2004 |
135 pages |
| Authors:
Thomas A. Niday; ARIZONA UNIV TUCSON OPTICAL SCIENCES CENTER
|
| Short, high intensity laser pulses induce nonlinear optical effects in the atmosphere that have the potential to make them propagate for long distances. Applications for long distance propagation of short pulses include active spectral remote sensing and laser lightning control. Much of the work in this field has been done with infrared pulses; however, it has been proposed that ultraviolet pulses have the advantage that longer pulse lengths can be ... |
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| Well-Conditioned Multi-Level Fast Multipole Modeling of Military Communication Channels |
30 AUG 2004 |
7 pages |
| Authors:
Lawrence Carin; DUKE UNIV DURHAM NC DEPT OF ELECTRICALENGINEERING
|
| Duke University and Virginia Polytechnic Institute and State University (VPI&SU) propose to team in a research effort to develop computer codes for the analysis and prediction of electromagnetic wave (EM) propagation over terrain. Those features of the terrain to be included are geographic scales of surface elevation, surface roughness, variable electrical constitutive properties, and vegetation cover (e.g., single and multiple trees). The frequencies to be considered include those of greatest ... |
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| Parallelization of a Electromagnetic Analysis Tool |
20 AUG 2004 |
7 pages |
| Authors:
Milissa Benincasa; Chris Card; Alan George; BLACK RIVER SYSTEMS COMPANY INC UTICA NY
|
| This paper describes research work currently being conducted under the Common High Performance Software Support Initiative (CHSSI) sponsored by the DoD High Performance Computing Modernization Program (HPCMO). A scalable, portable, parallel electromagnetic modeling tool is being developed that will provide the capability to rapidly generate scenes of radiating and scattering structures (targets and their surrounding environment) in realistically complex electromagnetic environments. This tool allows users to accurately model targets embedded ... |
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| Investigation of Electromagnetic Field Propagation in Reverse Saturable Absorbers |
05 JUL 2004 |
50 pages |
| Authors:
David W. McLaughlin; Mary Potasek; NEW YORK UNIV NY COURANT INST OF MATHEMATICAL SCIENCES
|
| We have developed and implemented a numerical technique for the propagation of the electromagnetic field in a five-level reverse saturable absorber medium, which includes the nonlinear Kerr effect and dispersion. The numerical method combines a split step beam propagation method with the Crank- Nicholson method. Our numerical results and calculations enable the prediction of nonlinear absorption using experimentally measurable material parameters such as the absorption cross-sections and decay rates. We ... |
|
| On the Addition of EM Field Propagation and Coupling Effects in the BLT Equation. Revision |
08-Jun-2004 |
44 pages |
| Authors:
F M Tesche; C M Butler; CLEMSON UNIV SC DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| Recent developments in electromagnetic (EM) field sources producing high power microwave (HPM) or ultra wide-band (UWB) transient signals have led to a concern about the effects of these environments on modern digital systems. Such excitations, which collectively are referred to as high power electromagnetic (HPEM) fields, could be inadvertent, like the environment produced by a search radar illuminating a nearby aircraft, or intentional, such as a deliberate attack on a ... |
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| Realizations of Electromagnetic Pulsed-Beam Wavelets and Applications of Physics-Based Radar Analysis and Sensing |
31 DEC 2003 |
5 pages |
| Authors:
Gerald Kaiser; VIRGINIA CENTER FOR SIGNALS AND WAVES GLEN ALLEN
|
| A solid and rigorous understanding of electromagnetic pulsed beam wavelet (PBW) sources has been established, though more work is needed to compute realizable current sources (eliminating magnetic charges). New results on using branch cuts to form spheroidal antennas are promising, as they determine the necessary boundary conditions to make the sources nonsingular. The recent computation of the 4D Fourier transform of PBW opens the way toward efficient numerical computations with ... |
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| Effects of Radio Wave Propagation in Urbanized Areas On UAV-GCS Command and Control |
DEC 2003 |
|
| Authors:
Lock W. Willy; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
 | The purpose of this research was to examine the effects of radiowave propagation in urbanized areas on unmanned aerial vehicle-ground control station (UAV-GCS) command and control. Operating at high frequency has merits of higher data rate transfer, which is crucial to support the large quantity of voice and video data to be transmitted via UAV-GCS linkage. However, high frequencies are attenuated more rapidly in lossy materials and weather. Having a ... |
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| Evaluation of EM Propagation Models Using Data from Wallops Island Experiment (2000) |
SEP 2003 |
162 pages |
| Authors:
Andrew J. Moys; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF METEOROLOGY
|
| The Royal Navy and the United States Navy emphasise utilising the environment to achieve a tactical edge Such approaches are outlined in Sea Power 21 This thesis recognizes accurate characterisation of the physical battlespace as vital to concepts of both self-defence (Sea Shield) and strike (Sea Strike), Electromagnetic (EM) propagation is presented as a vital factor in the performance of a wide variety of ship, land, and airborne sensors and ... |
|
| Bubble and Wave Measurements for the Rough Evaporation Duct (RED) experiment |
AUG 2003 |
14 pages |
| Authors:
Eric J. Terrill; W. K. Melville; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| The long term goals of this project are to better understand the influence of air-sea interaction processes on electromagnetic and electrooptical signal propagation including surface waves, spray generation, and the atmospheric conditions which lead to near-surface ducting of the signal in the atmosphere |
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| Time-Reversal for Electromagnetic Waves in Complex Media |
JUL 2003 |
16 pages |
| Authors:
Jean-Pierre Fouque; Mansoor A. Haider; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATHEMATICS
|
| A time-reversal mirror is, roughly speaking, a device which is capable of receiving an acoustic signal in time, keeping it in memory and sending it back into the medium in the reversed direction of time. In this paper, we employ an accurate numerical method for simulating waves propagating in complex one-dimensional media. We use numerical simulations to reproduce the time-reversal self-averaging effect which takes place in randomly layered media. This ... |
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| The Analytical Method of Investigation of Faraday Chiral Media |
11 JUN 2003 |
3 pages |
| Authors:
K. Vytovtov; DNIPROPETROVSK NATIONAL UNIV (UKRAINE)DEPT OF RADIOPHYSICS
|
| A plane-parallel homogeneous bianisotropic plate under an oblique incidence of a plane harmonic wave is considered. The bianisotropy axis is not coincide with a normal to a plate. The propagation and reflection coefficients are found in the analytical form. |
|
| Analytical Investigation of Periodic Media with Negative Parameters |
11 JUN 2003 |
4 pages |
| Authors:
K. Vytovtov; DNIPROPETROVSK NATIONAL UNIV (UKRAINE)DEPT OF RADIOPHYSICS
|
| The electromagnetic properties of an artificial layered material with negative permittivity and permibility are studied analytically. To analyses the translation matrix method is employed The translation matrix for multilayered structure is found in analytical form. The reflection and propagation coefficients of multilayered plate arc written in analytical form. The propagation conditions of a wave within periodic layered structure with negative parameters are obtained in analytical form. |
|
| Diffraction on the Eigen Waves on an Inclined Medium Interface in the Waveguides with Metallic Bounds |
11 JUN 2003 |
3 pages |
| Authors:
I. N. Pleshchinskii; N. B. Pleshchinskii; KAZAN STATE UNIV (RUSSIA)
|
| The electromagnetic wave diffraction problems on an inclined medium interface with a metallic plate and without it in the plane waveguide and in the rectangular waveguide are considered. It is shown that these problems can he reduced to boundary value problems for the Helmholtz equation or for the Maxwell system in a bounded rectangular domain. |
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| Modified Method of Geometric Electromagnetics for the Analysis of Radio Field in Marine Tropospheric Waveguides |
11 JUN 2003 |
3 pages |
| Authors:
Anatoly Bychkov; Alexei Bychkov; SEBASTOPOL NAVY INST (UKRAINE) DEPT OFRADIO ENGINEERING
|
| The interest for practical use of tropospheric waveguides (TWG) above the sea surface is still high. This is because there are many new tools for remote sensing of the atmosphere boundary layer and efficient methods for calculation of radiowave fields. Those TWG often form over the Black Sea. |
|
| Global Modeling of Compact High-Speed Circuits |
APR 2003 |
50 pages |
| Authors:
Y. A. Hussein; S. M. El-Ghazaly; ARIZONA STATE UNIV TEMPE TELECOMMUNICATIONS RESEARCH CENTER
|
| In this report, we present the work done during May 2002 to April 2003. We developed a fast wavelet-based time-domain modeling technique to study the effect of electromagnetic-wave propagation on the performance of high power and frequency multifinger transistors. The proposed approach solves the active device model that combines the transport physics, and Maxwell's Equations on nonuniform self-adaptive grids, obtained by applying wavelet transforms followed by hard thresholding. This allows ... |
|
| Computational Scattering Models for Elastic and Electromagnetic Waves in Particulate Media |
2003 |
222 pages |
| Authors:
Timothy Edwin Doyle; UTAH STATE UNIV LOGAN DEPT OF PHYSICS
|
| Numerical models were developed to simulate the propagation of elastic and electromagnetic waves in an arbitrary, dense dispersion of spherical particles. The scattering interactions were modeled with vector multipole fields using pure-orbital vector spherical harmonics, and solved using the full vector form of the boundary conditions. Multiple scattering was simulated by translating the scattered wave fields from one particle to another with the use of translational addition theorems, summing the ... |
|
| Analysis of Enhanced Second-Harmonic Generation in Periodic Nanostructures using Modified Rigorous Coupled-Wave Analysis in the Undepleted-Pump Approximation |
SEP 2002 |
11 pages |
| Authors:
Wataru Nakagawa; Rong-Chung Tyan; Yeshaiahu Fainman; CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING
|
| The authors present an extension of the rigorous coupled-wave analysis (RCWA) technique to analyze second-harmonic generation (SHG) in periodic optical nanostructures in the undepleted-pump approximation. They apply this method to analyze SHG in two example nanostructures for which they predict enhanced nonlinearity due to transverse near-field localization of the fundamental optical field in the nonlinear material. First, they examine a periodic nanostructure that yields up to twice the transmitted SHG ... |
|
| Extremely Low Frequency (ELF) Propagation Formulas for Dipole Sources Radiating in a Spherical Earth-Ionosphere Waveguide |
14 MAY 2002 |
182 pages |
| Authors:
Joseph P. Casey; NAVAL UNDERSEA WARFARE CENTER NEWPORT DIV RI
|
| Extremely low frequency (ELF) propagation formulas are derived for dipole sources radiating in a spherical earth-ionosphere waveguide. In these formulas, the earth and ionosphere boundaries are modeled as scalar surface impedances. The spherical waveguide formulas are applied to predict the electromagnetic fields produced by vertical and horizontal electric dipoles (located on the surface of the earth) at antipodal ranges for several frequencies and propagation conditions. These results are used to ... |
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| Numerical Modeling and Analysis of Transient Electromagnetic Wave Propagation and Scattering |
18 SEP 2001 |
12 pages |
| Authors:
Peter G. Petropoulos; NEW JERSEY INSTITUTE OF TECH UNIVERSITYHEIGHTS
|
| In 3 the P1 developed a scaling argument that proved useful in the derivation of reflectionless sponge layers to absorb outgoing time-harmonic waves in numerical solutions of the three-dimensional elliptic Maxwell equations in rectangular, cylindrical, and spherical coordinates. Also, this work developed these reflectionless sponge layers to absorb outgoing transient waves in numerical solutions of the time-domain Maxwell equations and proved that these absorbing layers are described by causal, strongly ... |
|
| Advanced Refractive Effects Prediction System (AREPS) |
AUG 2001 |
6 pages |
| Authors:
Wayne L. Patterson; SPACE AND NAVAL WARFARE SYSTEMS CENTER SAN DIEGO CA
|
| In 1987, SSC San Diego fielded the Integrated Refractive Effects Prediction System (IREPS), the world's first electromagnetic prediction system for shipboard use. Advances in research and technology have led to the replacement of IREPS with the Advanced Refractive Effects Prediction System (AREPS). AREPS computes and displays radar probability of detection, propagation loss and signal-to-noise ratios, electronic-support-measures vulnerability, UHF/ VHF communications, and surface-borne surface-search radar capability versus range, height, and bearing ... |
|
| Computation of Nonlinear Backscattering Using a High-Order Numerical Method |
JUL 2001 |
13 pages |
| Authors:
G. Fibich; B. Ilan; S. Tsynkov; INSTITUTE FOR COMPUTER APPLICATIONS IN SCIENCE AND ENGINEERING HAMPTON VA
|
| The nonlinear Schrodinger equation (NLS) is the standard model for propagation of intense laser beams in Kerr media. The NLS is derived from the nonlinear Helmholtz equation (NLH) by employing the paraxial approximation and neglecting the backscattered waves. In this study we use a fourth-order finite- difference method supplemented by special two-way artificial boundary conditions (ABCs) to solve the NLH as a boundary value problem. Our numerical methodology allows for ... |
|
| Clear-Air Effects on Airborne Sensors |
29 MAY 2001 |
35 pages |
| Authors:
Mireille F. Levy; RUTHERFORD AND APPLETON LABS CHILTON (UNITED KINGDOM)
|
| This report results from a contract tasking Council for the Central Laboratory of the Research Councils as follows: The contractor shall investigate novel approaches to using stochastic modeling to study radar propagation in the UK AWACS. Simulated data will be used to study the impact of refractive index fluctuations due to turbulence and determine if these phenomena will fill the radar holes or deepen them. The deliverables will consist of ... |
|
| Development and Experimental Evaluation of Oceanic Evaporation Duct Models Based on the LKB Approach |
30 MAR 2001 |
8 pages |
| Authors:
Steven M. Babin; G. D. Dockery; JOHNS HOPKINS UNIV LAUREL MD APPLIED PHYSICS LAB
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| Comparison is made between four evaporation duct models based on the surface layer theory of Liu, Katsaros and Businger. These models are used to generate modified refractivity (M) profiles that are then compared with those determined from time-averaged atmospheric data measured by the JHU/APL profiling buoy. Model inputs are derived from measurements from masts on the R/V CHESSIE and a tethered sea-surface temperature (SST) buoy. Because electromagnetic propagation is critically ... |
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| Attenuation and Refraction of an Electromagnetic Wave in an Electron Beam Generated Plasma |
FEB 2001 |
166 pages |
| Authors:
Nathaniel P. Lockwood; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT
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| Artificially generated plasmas may be employed to alter the propagation characteristics of electromagnetic waves. The purpose of this report is to study the propagation of electromagnetic waves in an electron beam generated plasma. To understand the physics related to this concept requires the development of computational tools dealing with a plasma created by an electron beam, an assessment of the temporal and spatial evolution of the plasma, and a characterization ... |
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Reports by Keyword(s)
*ELECTROMAGNETIC WAVE PROPAGATION
