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K-space formulation of the two-dimensional electromagnetic scattering problem /Krueger, Charles Huston January 1972 (has links)
No description available.
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Modeling spontaneous undulator emissions using Lienard-Wiechert fieldsHallman, Susan 01 April 2003 (has links)
No description available.
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SUBSYSTEM RADIATION MEASUREMENTS USING A RECTANGULAR TRANSVERSE ELECTROMAGNETIC CELL.Dezember, Michael Jo. January 1984 (has links)
No description available.
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Polarization dependent radar return from rough surfacesKrishen, Kumar. January 1966 (has links)
Call number: LD2668 .T4 1966 K92 / Master of Science
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Identification of parameters describing a conductor-backed dielectric slabTran, Huong Ngoc, 1966- January 1989 (has links)
In this parametric inverse problem, we consider a lossless dielectric slab excited by a transient plane wave. The scattered electric field from the slab is presented in the ray-optic and the complex-resonance forms. Our interest is to extract the complex-resonances of the system in order to identify the parameters that describe the scatterer. We review the signal processing procedure and the identification procedure employed to identity the poles of the system. We investigate the effect of noise on identification and determine the maximum amount of noise one can impose on the system. In addition, we study the effect of data truncation on our identification procedure. We also discuss the parameters that dictate the minimum record required for successful identification. Finally, we demonstrate some similarities in effect of noise and truncation on our identification process.
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Fourth-order finite difference methods for the time-domain Maxwell equations with applications to scattering by rough surfaces and interfacesXie, Zhongqiang January 2001 (has links)
No description available.
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Performance analysis of variable code rate signals transmitted over frequency-nonselective, slowly fading channels in a pulse-interference environmentShih, Wan-Chun 09 1900 (has links)
Wireless systems, including wireless local area networks (WLAN) and cellular networks, are increasingly being used for both commercial and military applications. For military applications, it is important to analyze the effect of interference on wireless communications systems. The objective of this research is to investigate the performance of variable code rate signals transmitted over frequency-nonselective, slowly fading channels in a worst case, pulse-noise interference environment. Both binary phase-shift keying (BPSK) and noncoherently detected binary frequency-shift keying (NCBFSK) are considered. System performance with both Viterbi hard decision decoding (HDD) and soft decision decoding (SDD) is analyzed for additive white Gaussian noise (AWGN) alone and for AWGN plus pulse-noise interference for various receiver types and conditions of channel fading. The effect of varying the code rate, both for HDD and SDD, is examined. The amplitude of the signal power 2 c a is modeled as a random variable, and the channel is modeled as either Rayleigh fading or Ricean fading, depending on the modulation under consideration.
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Performance analysis of the IEEE 802.11G waveform transmitted over a fading channel with pulse-noise interferenceTaxeidis, Konstantinos 06 1900 (has links)
The performance of the most promising wireless local area network (WLAN) standards today, IEEE 802.11g, which specifies orthogonal frequency-division multiplexing in order to avoid multi-path effects and at the same time achieve high data rates, was examined in this thesis. We investigated four different receivers and analyzed their performance with Viterbi soft decision decoding when the signal was transmitted over a slow, flat fading Nakagami channel for AWGN only, as well as for AWGN plus pulse-noise interference. The implementation of forward error correction coding with soft decision decoding improves the performance compared to uncoded signal if pulse-noise interference is not present. The scenarios when no side information is available (linear-combining receiver), when perfect side information is available (noise-normalizing receiver), and two alternatives to the noise-normalized receiver with much coarser side information (modified noise-normalized receiver and noise-normalized receiver with normalization error) are examined. All the scenarios are examined for various fading and interference conditions. The performance of the noise-normalized receiver is, as expected, much improved compared to the linear-combining receiver when PNI is present. Finally, the noise-normalized receiver with normalization error achieves the same or better performance than the noise-normalized receiver without the exact interference noise power.
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An approximation to the Heidler Function with an analytical integral for engineering applications using lightning currentsTerespolsky, Brett Ryan January 2015 (has links)
A dissertation submitted to the Faculty of Engineering and the Built
Environment, University of the Witwatersrand, Johannesburg, in fulfilment of
the requirements for the degree of Master of Science in Engineering
in the
Lightning and EMC Research Group
School of Electrical and Information Engineering
September 2015 / The work presented contributes to research in lightning protection simulations and focuses
on approximating the Heidler function with an analytical integral and hence a
frequency domain representation. The integral of lightning current models is required
in the analysis of lightning events including the induced effects and frequency analyses
of lightning strikes. Previous work in this area has produced very specific forms of the
Heidler function that are used to represent lightning current waveshapes. This work
however focuses on a generic solution with parameters that can be modified to produce
any lightning current waveshape that is required. In the research presented, such an
approximation is obtained. This function has an analytical solution to the integral and
hence can be completely represented in the frequency domain. This allows for a true
representation of Maxwell’s equations for Electromagnetic (EM) fields and for an analytical
frequency domain analysis. It has parameters that can be changed to obtain
different waveshapes (10/350, 0.25/100, etc.). The characteristics of the approximation
are compared with those of the Heidler function to ascertain whether or not the function
is applicable for use with the lightning protection standard (IEC 62305-1). It is shown
that the approximation does represent the same characteristics as those of the Heidler
function and hence can be used in IEC 62305-1 standardised applications. This represents
a valuable contribution to engineers working in the field of lightning protection,
specifically simulation models. / MT2017
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Theory of photonic band gap materials.January 1994 (has links)
Lee Wai Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1994. / Includes bibliographical references (leaves 177-181). / List of Figures and Tables --- p.iii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Photonic Band Gap materials --- p.1 / Chapter 1.2 --- Theoretical Calculation on PBG materials --- p.5 / Chapter 2 --- Plane Wave Expansion --- p.13 / Chapter 2.1 --- Plane Wave Expansion within Scalar Wave Approximation --- p.14 / Chapter 2.2 --- Plane Wave Expansion to Scalar I and II Equations --- p.21 / Chapter 3 --- Formalism of Photonic k.p Theory --- p.33 / Chapter 3.1 --- Vectorial k.p formulation --- p.33 / Chapter 3.2 --- Scalar k. p formulations --- p.36 / Chapter 4 --- Implementation and k.p Band Structures --- p.38 / Chapter 4.1 --- Evaluation of Integrals plj and qlj --- p.38 / Chapter 4.2 --- k.p Band Models --- p.47 / Chapter 5 --- Dependence of k .p Parameters on Dielectric Contrast and Fill- ing Ratio --- p.57 / Chapter 5.1 --- Accuracy of Integrals plj and qlj --- p.57 / Chapter 5.2 --- Sensitivity of k.p Parameters to System Parameters --- p.71 / Chapter 6 --- Empirical Tight-binding Scheme --- p.99 / Chapter 6.1 --- Electronic Tight Binding Approximation --- p.99 / Chapter 6.2 --- Empirical Tight-binding Scheme --- p.101 / Chapter 7 --- Summary --- p.137 / Chapter A --- Preprint of Ref. [36] --- p.144 / Chapter B --- The Coefficients in Eq. (2.22) --- p.161 / Chapter C --- Formalism of Photonic k.p Theory --- p.163 / Chapter D --- The Coefficients in Eq. (5.2) --- p.166 / Chapter E --- The Coefficients in Eq. (5.3) --- p.168 / Chapter F --- The Coefficients in Eq. (6.15) --- p.170
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