• Title/Summary/Keyword: Double-scattering

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Analysis of H-polarized Electromagnetic Scattering by a Conductive Strip Grating Between a Grounded Double Dielectric Layer Using FGMM (FGMM을 이용한 접지된 2중 유전체층 사이의 완전도체띠 격자구조에 의한 H-분극 전자파 산란 해석)

  • Yoon, Uei-Joong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.1
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    • pp.83-88
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    • 2020
  • In this paper, H-polarized electromagnetic scattering problems by a conductive strip grating between a grounded double dielectric layer are analyzed by applying the FGMM(Fourier-Galerkin Moment Method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, and the conductive boundary condition is applied to analysis of the conductive strip. The numerical results for normalized reflected power are analyzed by according as the width and spacing of conductive strip, the relative permittivity and thickness of the grounded double dielectric layers, and incident angles. Generally, as the value of the dielectric constant and dielectric thickness of a grounded double dielectric layer increases, the reflected power increased. And as dielectric thickness of a grounded double dielectric layer increases, the current density induced in the strip center increases. The numerical results for the presented structure of this paper are shown in good agreement compared to those of the existing papers using the PMM(Point Matching Method).

Scattering of a Normally Incident Monochromatic Light by Optically Active Concentric Double Cylinders: I. Analytic Theory (광학활성 동축 이중 원통을 수직하게 비추는 단색 빛의 산란 : I. 해석적 이론)

  • Kim, Hyun-Woo;Kim, Jin-Seung
    • Korean Journal of Optics and Photonics
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    • v.20 no.6
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    • pp.366-374
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    • 2009
  • An analytic solution is obtained for the problem of monochromatic light scattering by optically active, concentric double cylinders. The validity of the obtained solution is indirectly checked by comparing it with solutions already reported for some special cases. The solution can be used in the optical analysis of rod-shaped biological cells which possibly have optically active nuclei containing helically wound chromosomes.

A Simple Microwave Backscattering Model for Vegetation Canopies

  • Oh Yisok;Hong Jin-Young;Lee Sung-Hwa
    • Journal of electromagnetic engineering and science
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    • v.5 no.4
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    • pp.183-188
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    • 2005
  • A simple microwave backscattering model for vegetation canopies on earth surfaces is developed in this study. A natural earth surface is modeled as a two-layer structure comprising a vegetation layer and a ground layer. This scattering model includes various scattering mechanisms up to the first-order multiple scattering( double-bounce scattering). Radar backscatter from ground surface has been modeled by the polarimetric semi-empirical model (PSEM), while the backscatter from the vegetation layer modeled by the vector radiative transfer model. The vegetation layer is modeled by random distribution of mixed scattering particles, such as leaves, branches and trunks. The number of input parameters has been minimized to simplify the scattering model. The computation results are compared with the experimental measurements, which were obtained by ground-based scatterometers and NASA/JPL air-borne synthetic aperture radar(SAR) system. It was found that the scattering model agrees well with the experimental data, even though the model used only ten input parameters.

Scattering of a Normally Incident Monochromatic Light by Optically Active Concentric Double Cylinders: II. Numerical Result (광학활성 동축 이중 원통을 수직하게 비추는 단색 빛의 산란 : II. 수치 계산 결과)

  • Kim, Hyun-Woo;Kim, Jin-Seung
    • Korean Journal of Optics and Photonics
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    • v.20 no.6
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    • pp.375-380
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    • 2009
  • The scattering of a normally incident monochromatic light by optically active concentric double cylinders is studied by using a numerical method. A numerical code is developed on the basis of the analytical solutions, and the angular distributions of the intensity and the polarization of the scattered light are computed for some specific cases. The numerical code can be used to non-invasively determine the size, structure, and composition of a double cylinder with high accuracy by measuring the angular distribution of the scattered light by an experiment.

Resonant inelastic X-ray scattering of tantalum double perovskite structures

  • Oh, Ju Hyun;Kim, Jung Ho;Jeong, Jung Hyun;Chang, Seo Hyoung
    • Current Applied Physics
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    • v.18 no.11
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    • pp.1225-1229
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    • 2018
  • In this paper, we investigated the electronic structures and defect states of $SrLaMgTaO_6$ (SLMTO) double perovskite structures by using resonant inelastic x-ray scattering. Recently, $Eu^{3+}$ doped SLMTO red phosphors have been vigorously investigated due to their higher red emission efficiency compared to commercial white light emitting diodes (W-LED). However, a comprehensive understanding on the electronic structures and defect states of host SLMTO compounds, which are specifically related to the W-LED and photoluminescence (PL), is far from complete. Here, we found that the PL spectra of SLMTO powder compounds sintered at a higher temperature, $1400^{\circ}C$, were weaker in the blue emission regions (at around 400 nm) and became enhanced in near infrared (NIR) regions compared to those sintered at $1200^{\circ}C$. To elucidate the difference of the PL spectra, we performed resonant inelastic x-ray spectroscopy (RIXS) at Ta L-edge. Our RIXS result implies that the microscopic origin of different PL spectra is not relevant to the Ta-related defects and oxygen vacancies.

Scattering from a Periodic Array of Duble-Dipole Elements over a Grounded Dielectric Slab

  • Ko, Jin-Whan
    • ETRI Journal
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    • v.20 no.1
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    • pp.46-54
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    • 1998
  • An analysis method of electromagnetic scattering from periodic patch array of double-dipole elements on a grounded dielectric substrate in case of oblique incident and arbitrary polarization is considered. The basis functions are chosen to be entire consinusoidal functions are chosen to be entire consinusoidal functions covering the rectangular shaped domain in which the original dipoles are inscribed, unlike the conventional method in which basis functions are defined only for the conducting element region. To confirm the validity of the proposed analysis method, we calculate the normalized scattered power for two propagating modes and compare the results with those obtained by the previous numerical method for the double dipole elements of rectangular type and parallelogram type which have the property of frequency scanned reflection and polarizer. Good correspondence has been observed between them. Some numerical results such as variation of power and axial ratio of first-order diffracted wave by a periodic array of double-dipole elements are compared with previous results.

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Improvement of Polarization Maintenance Property of Scattering Polarizer Film for Double-Screen 3D Projection Display Screen Applications Via Surface Oxide Deposition (산화막 증착을 통한 이중스크린 3D 프로젝션 디스플레이 스크린용 산란형 편광필름의 편광유지도 개선)

  • Kim, Dae-Yeon;Seo, Jong-Wook
    • Journal of the Semiconductor & Display Technology
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    • v.11 no.4
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    • pp.1-6
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    • 2012
  • Keeping the polarization direction of the projection light unchanged is of crucial importance for high quality of images on a double-screen 3D projection display system. It has been found that the deposition of oxide layers on the surfaces of scattering polarizer film results in an improvement of polarization maintenance property of the film. The secondary image formed on the front screen by the light scattered from the rear screen decreases by 30% through the application of oxide layers on both surfaces of the screen. Since the oxide layer can also be used as an anti-reflection (AR) coating of the film, this method is very effective for the projection display applications.

A Study on TE Scattering by a Conductive Strip Grating between Grounded Double Dielectric Layer (접지된 2중 유전체층 사이의 완전도체띠 격자구조에 의한 TE 산란에 관한 연구)

  • Yoon, Uei-Joong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.16 no.4
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    • pp.153-158
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    • 2016
  • In this paper, TE(transverse electric) scattering problems by a conductive strip grating between grounded double dielectric layer are analyzed by applying the PMM(point matching method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the conductive boundary condition is applied to analysis of the conductive strip. The numerical results for normalized reflected power are analyzed by according as the width and spacing of conductive strip, the relative permittivity and thickness of the double dielectric layers, and incident angles. The most normalized reflected powers of the sharp variations in minimum values are scattered in direction of the other angles except incident angle. The numerical results for the presented structure of this paper having a grounded double dielectric layer are shown in good agreement compared to those of the existing papers.

A Study on TM Scattering by a Conductive Strip Grating Between a Double Dielectric Layer (2중 유전체층 사이의 완전도체띠 격자구조에 의한 TM 산란에 관한 연구)

  • Yoon, Uei-Joong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.2
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    • pp.73-79
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    • 2018
  • In this paper, TM(transverse magnetic) scattering problems by a conductive strip grating between a double dielectric layer are analyzed by applying the PMM(point matching method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, the scattered electromagnetic fields are expanded in a series of Floquet mode functions, and the conductive boundary condition is applied to analysis of the conductive strip. The most normalized reflected powers of the sharp variations in minimum values are scattered in direction of the other angles except incident angle. Generally, in the case of numerical analysis except for reflection and transmission power in free space, as the dielectric constants of the double dielectric layer increases, the reflected power increases and the transmitted power decreases relatively, respectively. The numerical results for the presented structure of this paper having a grounded double dielectric layer are shown in good agreement compared to those of the existing papers.

A Study on TM Scattering by a Resistive Strip Grating Between a Double Dielectric Layer (2중 유전체층 사이의 저항띠 격자구조에 의한 TM 산란에 관한 연구)

  • Yoon, Uei-Joong
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.21 no.1
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    • pp.49-54
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    • 2021
  • In this paper, n this paper, E-polarized electromagnetic scattering problems by a resistive strip grating between a double dielectric layer are analyzed by applying the PMM(Point Matching Method) known as a numerical method of electromagnetic fileld. The boundary conditions are applied to obtain the unknown field coefficients, and the resistive boundary condition is applied to analysis of the resistive strip. The numerical results for the normalized reflected and transmitted power are analyzed by according as the relative permittivity and thickness of the double dielectric layers, and the resistivity of resistive strip. Overall, when the resistivity of the resistive strip decreased or the relative permittivity of the dielectric layer increased, the reflected power increased, and as the reflected power increased, the transmitted power decreased relatively. Especially, as the relative permittivity of double dielectric layer increases, the minimum value of the variation curve of the reflected power shifted in the direction that the grating period decreased. The numerical results for the presented structure of this paper are shown in good agreement compared to those of the existing papers.