DOI： 10.2528/PIERC18111403

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DOI： 10.23919/APMC.2018.8617662

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DOI： 10.1109/COMPEM.2018.8496669

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

We considered the scattering and absorption of the H and E-polarized plane waves by an infinite flat graphene strip grating placed in a dielectric slab, in the THzrange. Accurate numerical treatment was based on the singular integral equations and their projection to specially tailored orthogonal polynomials. The resulting numerical algorithm possessed guaranteed convergence and provided controlled accuracy. Reflectance, transmittance, and absorbance were studied, and the resonances on the surface-plasmon modes, the grating modes, and the slab modes were identified. The grating or lattice modes are caused by the periodicity. Their complex frequencies are extremely close to Rayleigh anomalies and therefore the Q-factors are extraordinarily high, which makes them promising in various applications.

DOI： 10.1109/JSTQE.2017.2684082

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

Light scattering from infinite and finite periodic arrays of silver nanospheres is numerically analyzed based on mode expansions. Comparisons of the far field pattern and the power distribution reveal that the conformation of grating lobes becomes evident as the number of spheres is increased.

DOI： 10.1109/COMPEM.2017.7912819

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

We demonstrate an accurate and powerful numerical solution to the light scattering from a set of nano-strips made of noble metals stacked in parallel. With the aid of the generalized boundary conditions, the problem is formulated into the singular integral equations for unknown electric and magnetic current density on the strip, In the procedure of the moment method, Legendre and Chebyshev polynomials are successively employed as the basis and testing functions. Numerical examples show the the effectiveness of the solution.

DOI： 10.1109/MMET.2016.7544091

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

We considered the scattering and absorption of the H-polarized plane wave by an infinite flat graphene-strip grating in a dielectric slab, in the THz range. Accurate numerical treatment was based on the singular integral equation (IE) and projection to orthogonal polynomials. The resulting numerical algorithm possesses guaranteed convergence and controlled accuracy of computations including the vicinities of sharp resonances. Reflectance, transmittance, and absorbance by the graphene-strip grating were studied. The resonances on the surface-plasmon modes, grating modes, and slab modes were identified.

DOI： 10.1109/EuCAP.2016.7481170

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Electromagnetics Academy  

Numerical solution is presented for light scattering from two kinds of free-standing periodic arrays, that is, disks made of noble-metal and circular apertures perforated in a thin noble-metal sheet. The shapes of them are complementary to each other, and the circular areas are allocated along two orthogonal coordinates with the same periodicity. Using the generalized boundary conditions of the surface impedance type, we formulate the boundary value problem into a set of integral equations for unknown electric and magnetic current densities defined over the circular area. Employment of the method of moments allows us to solve the integral equations and give the expansion coefficients of the current densities, from which we can find reflected, transmitted, and absorbed powers. Dependence of the powers on the array parameters and wavelength is discussed in detail from the viewpoint of grating resonance. Special attention is paid to the extraordinary transmission which occurs in the arrays of apertures of sub-wavelength size by analytical derivation of the quasi-static solutions.

DOI： 10.2528/PIERM15040201

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

We consider the scattering and absorption by infinite flat graphene strip gratings in a dielectric slab in the THz range. Both the H and E-polarization regimes are analyzed. Accurate numerical treatment is based on the use of singular integral equations and projection to orthogonal polynomials. The resulting numerical algorithm possesses guaranteed convergence and controlled accuracy of computations including the natural resonances. Reflectance, transmittance, and absorbance by the graphene-strip gratings are studied; surface-plasmon standing-wave resonances on strips are quantified in the H-polarization case. The potentialities of the polarization discrimination between the E-polarization and H-polarization cases are discussed.

DOI： 10.1109/EuMC.2015.7345732

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：ELECTROMAGNETICS ACAD  

Surface plasmon-coupled emission microscopy (SPCEM) that makes use of a thin layer of metal deposited on glass slides to efficiently excite fluorophore and to collect the emission light is a widely used imaging technique that has found a number of applications in areas such as biotechnology and biological measurements. SPCEM is a relatively new imaging technique that potentially promises better detection sensitivity and higher signal-to-noise ratio than conventional total internal reflection fluorescence (TIRF) imaging. However, recent theoretical studies suggest that the sensitivity of SPCEM is actually reduced due to the metal layer. We have designed a metal-dielectric multilayer film structure which consists of Ag-Si3N4 layers, and we have analyzed the transmission of two counter-propagation lights from the multilayer film by using the characteristic matrix method in the film optics. In this paper, optimization is utilized in the design of the multilayer film structure. And it is coated on the glass slides to improve the quality of microscopic imaging. We mainly use the optimization method to design the thickness of the metal layer and the dielectric layer. We analyze the transmission coefficient of two counter propagation lights from the multilayer film with different thickness and different number of layer. The refractive indexes with different number of the layer of multilayer film are also discussed.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：ELECTROMAGNETICS ACAD  

We develop the concept of the near-field optical storage using a NIF and propose a new near-field solid immersion lens (SIL) optical recording system. Our method is based on the surface plasmas (SP) excited by a NIF-polymer composite nano-layer which is attached on the plane surface of the SIL. An experimentally-fabricated negative index material comprising silver nanorods is chosen as the NIF and the refractive indices mismatching effect is considered in our simulations. The proposed system may be much more close to an actual near-field optical recording system.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

The scattering and absorption of the H and E-polarized plane waves by a flat grating of free standing graphene strips is studied in the THz frequency range. We use the Kubo theory to characterize the surface impedance of graphene and reduce the boundary-value problems to the equivalent integral equations, hyper-singular on the H-case and log-singular in the E-case. Then we discretize them using the projection to the set of orthogonal polynomials; in the H-case these polynomials are chosen to perform the analytical regularization. In each case this technique guarantees fast convergence and controlled accuracy of computations. Reflectance, transmittance, and absorbance of graphene-strip gratings are studied as a function of various parameters. In the H-polarization regime, we find the surface-plasmon resonances and small-scale Rayleigh anomalies. In the E-polarization case, there are no [plasmons however the Rayleigh anomalies become well observable. These results can be considered as reference ones opening way to the accurate modeling of tunable absorbers and frequency selective surfaces based on the periodically patterned graphene layers.

DOI： 10.1109/MIKON.2014.6899932

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For recent VLSI circuits, the clock frequency and integration density have continuously increased. Thus, accurate estimate of the per-unit-length resistance and inductance of interconnect has become important for maintaining the signal integrity [1]. In order to design for the transmission lines successfully, it is necessary that correctness of the selected formulas or numerical methods can take into account AC loss due to the skin and proximity effects [2]. The integral equation method is an effective tool for calculating the per-unit-length impedance or current density distributions in the rectangular cross section of metallic lines [3]. Considering that the increase in resistance due to the eddy current flowing in lossy semiconductor substrate has attracted attention nowadays [4], it is advantageous if we can extend the powerful integral equation solutions to this case. © 2012 IEICE.

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An efficient numerical solution is presented for computing per-unit-length impedance of metallic rectangular transmission lines backed by semi-infinite lossy substrate. We formulate the problem into the set of integral equations, the kernel of which is analytically expressed in terms of special functions in the quasi-static regime. The method of moments is applied to find the current density distributions in the metal regions, where the discretization of cross sections is performed by using non-uniform grid arranged according to the skin effect. The practical numerical computations concern the inouence of the substrate loss on the per-unit-length impedance for some types of parallel lines. We thereby show that the substrate loss cannot be neglected at high frequencies. The e®ectiveness of the proposed method is confirmed by showing that the computed values of resistance satisfy the law of energy conservation with acceptable accuracy.

DOI： 10.2528/PIERB12071105

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An effcient numerical solution is been developed to compute the impedances of rectangular transmission lines. Method of moments is applied to integral equations for the current density, where the cross section is discretized, to improve the convergence, by a nonuniform grid that obeys the skin effect. Powerfulness of this approach up to rather high frequencies is verified by comparing with asymptotic formulas and other references. Detailed discussion is given for the current density distribution and its effect to the impedance, especially for a high frequency range.

DOI： 10.2528/PIERM11122105

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

This letter reports the result of modeling of the tropical rain attenuation at 28 GHz adopting the auto-regressive integrated moving average (ARIMA) model. The result obtained is useful for the evaluation of transmission system design in radio communications at millimeter-wave frequencies in tropical areas. In this research, radio power measurement on a 56.4-m link at 28 GHz was carried out in Surabaya, Indonesia, with a data acquisition system that recorded a sample once every second. Approximation of the data by ARIMA(p, d, q) models for every rain event was carried out in order to obtain a valid time series model. In the validation, comparisons were made of the distributions of attenuation from the models against those from direct measurement of attenuation and from estimation based on the synthetic storm method. Comparisons were also made of the attenuation slope distributions against that from the measurement. Each of rain attenuation time series obtained from events in February 2009 was found to be well approached by the ARIMA model with various sets of parameters (p, d, q). The best model was found to be ARIMA(0, 1, 1), as indicated by the Akaike Information Criteria (AIC) and Schwarz Bayesian Criteria (SBC) test results. A procedure for generating rain events based on the model is presented.

DOI： 10.1109/LAWP.2010.2046130

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：Electromagnetics Academy  

Specific rain attenuation is discussed from the viewpoint of numerical solution for scattering and absorption of electromagnetic waves related to dielectric spheres. Special attention is paid to the quantitative evaluations considering the change of temperature and the existence of multiple scattering effect. The analysis is based on the set of Stratton's vector spherical wave functions and its addition theorem, which lead to the simultaneous linear equations for the expansion coefficients with adaptively selected truncation numbers. Computed extinction cross sections lead directly to the specific rain attenuation, where the Weibull raindrop distribution model is used. It is discussed how the dependence of the permittivity of water on temperature and frequency affects the attenuation property. Furthermore, the effect of multiple scattering is evaluated in terms of the root mean square of attenuation deviation from the simple superposition of single scattering (Mie's) coefficients. Contrary to general belief, this deviation is the highest at around the boundary between microwave and millimeter wave bands.

DOI： 10.2528/PIER09102609

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

We present a full-wave numerical study and design of the 2-D model of a perfectly electric conducting (PEC) parallel-plate waveguide lens antenna. Our consideration deals with the E-polarization. It is based on the coupled Singular Integral Equations (SIEs) discretized using a Nystrom-type numerical algorithm, which provides exponential convergence. This enables us to study symmetric and modified side-notched metal-plate lens antennas and make elementary optimization of the feed to achieve the best directivity.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

The present paper numerically clarifies the degree of multiple scattering effects, which has been believed to become significant at high frequencies more than several hundred gigahertz. The specific rain attenuation is evaluated directly from an extinction cross section of dielectric spheres. A set of small dielectric spheres are randomly allocated inside a big fictitious sphere by using Weibull raindrop size distribution model. In order to take account of the multiple scattering among raindrops, we employ the mode matching method based on vector spherical wave functions and its addition theorem. Numerical results are demonstrated for the root mean square deviation of the specific attenuation between the cases with and without multiple scattering terms. Contrary to general belief, the deviation is the highest at around the boundary between microwave and millimeter wave bands.

DOI： 10.1109/APMC.2009.5384299

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：E M W PUBLISHING  

Specific rain attenuation is discussed from the viewpoint of numerical solution for scattering and absorption of electromagnetic waves related to dielectric spheres. Special attention is paid to the quantitative evaluations considering the change of temperature and the existence of multiple scattering effect. The analysis is based on the set of Stratton's vector spherical wave functions and its addition theorem, which lead to the simultaneous linear equations for the expansion coefficients with adaptively selected truncation numbers. Computed extinction cross-sections lead directly to the specific rain attenuation, where the Weibull rain drop distribution model is used. It is discussed how the dependence of the permittivity of water on temperature and frequency affects the attenuation property. Furthermore, the erect of multiple scattering is evaluated in terms of the root mean square of attenuation deviation from the simple superposition of single scattering (Mie's) coefficients. Contrary to general belief, this deviation is the highest at around the boundary between microwave and millimeter wave bands

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/APS.2008.4619381

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

Results of rain attenuation statistics measurement in Surabaya using an optical disdrometer is reported. Rain attenuation statistic obtained simulation of the synthetic storm technique applied to the rain rate time series measurements closely with results obtained from ITU-R P.530-10 for outage probabilities 0.01-0.1%. For an outage probabilities less than 0.01 % that predicted by SST have large rain attenuation than ITU-R P.530-10. The simulation results show that the incident direction of storm velocity and the assumption link location, influence rain attenuation statistic.

DOI： 10.1109/WOCN.2008.4542528

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：E M W PUBLISHING  

An effective numerical solution is presented for the plane wave scattering by multilayered periodic arrays of dielectric spheres. The treated structure is a fundamental model of photonic crystals having three-dimensional periodicity. The problem is analyzed by the mode matching method, where the electromagnetic fields in the air and dielectric regions are approximated by using the Floquet harmonics and vector spherical wave functions, respectively. They are matched on the junction surfaces in the least squares sense. Introduction of sequential accumulation in the process of QR decomposition reduces the computation time from O(Q(3)) to O(Q(1)) and the memory requirement from O(Q(2)) to O(Q(1)), with Q being a number of sphere layers. Numerical results are given for CPU time, speed of convergence, and some band gap characteristics.

DOI： 10.2528/PIER06123002

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

Measurement of time-varying rain rate has been performed in Surabaya using an optical disdrometer. The results suggest that consecutive samples of rain rate in Surabaya possesses higher correlation than those measured in such non-tropical sites like Barcelona. Attenuation statistics obtained from a simulation study by means of the synthetic storm technique applied to the rain rate time series measurements agree with those predicted by ITU-R only for links of 1-2 km length at outage probabilities in the range of 0.01-0.1%. The simulation results also show that the use of daily and monthly averages of wind velocity does not yield significant differences in the attenuation statistics.

DOI： 10.1109/KJMW.2007.4402248

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：E M W PUBLISHING  

An effective computational method based on a conventional modal-expansion approach is presented for solving the problem of diffraction by a deep grating. The groove depth can be the same as or a little more than the grating period. The material can be a perfect conductor, a dielectric, or a metal. The method is based on Yasuura's modal expansion, which is known as a least-squares boundary residual method or a modified Rayleigh method. The feature of the present method is that: (1) The semi- infinite region U over the grating surface is divided into an upper half plane U-0 and a groove region U-G by a fictitious boundary (a horizontal line); (2) The latter is further divided into shallow horizontal layers U-1, U-2, center dot center dot center dot, U-Q again by fictitious boundaries; (3) An approximate solution in U-0 is defined in a usual manner, i.e., a finite summation of up-going Floquet modal functions with unknown coefficients, while the solutions in U-q (q = 1, 2,center dot center dot center dot, Q) include not only the up-going but also the down-going modal functions; (4) If the grating is made of a dielectric or a metal, the semi-infinite region L below the surface is partitioned similarly into L-0, L-1, center dot center dot center dot, L-Q, and approximate solutions are defined in each region; (5) A huge-sized least squares problem that appears in finding the modal coefficients is solved by the QR decomposition accompanied by sequential accumulation. The method of solution for a grating made of a perfect conductor is described in the text. The method for dielectric gratings can be found in an appendix. Numerical examples include the results for perfectly conducting and dielectric gratings.

DOI： 10.2528/PIER06071401

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：SCRIPTA TECHNICA-JOHN WILEY & SONS  

The increase of the working frequencies of electromagnetic wave circuits causes high transmission losses due to the roughness of the metal surfaces. To understand this phenomenon, we model a rough metal interface in the simplest manner, by periodic grooves of infinite length. Then the reduced two-dimensional problem is analyzed numerically by the equivalent source method. Two polarizations are treated separately: the H-wave case, in which the directions of grooves and current are perpendicular, and the E-wave case, in which they are parallel. Three cross-sectional shapes of the metal surface-rectangular, triangular, and semielliptical conductors-are selected for computing the power losses and local surface impedances. We observe how the shape and groove depth affect the above characteristics, and investigate the behavior of the numerical results physically by taking account of the field distributions. (c) 2005 Wiley Periodicals, Inc.

DOI： 10.1002/ecjb.20218

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Language：Japanese   Publisher：一般社団法人電子情報通信学会  

無限長の細い誘電体円柱を一方向に周期的に並べた格子の等価回路パラメータを求めている.平面波が入射したときの誘電体の散乱効果を, 円柱軸上の実効分極電流及び直交する二つの電流双極子モーメントで表現した.求めた等価リアクタンスをもつ素子を伝送線路内に周期的に装荷すれば, フォトニック結晶の阻止特性を容易に求めることができる.

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Language：Japanese   Publisher：一般社団法人電子情報通信学会  

電磁波回路の動作周波数の上昇に伴い, 金属の表面粗さによる伝送損の増大が問題になっている.この現象を把握するために, 粗い導体表面を周期的な無限長の溝により最も単純にモデル化し, 二次元問題に帰着させて, 等価波源法により数値解析する.偏波については, 溝の向きが電流に対して垂直なH波の場合と平行なE波の場合を個別に扱う.導体突起部の断面形状として, 方形, 三角形, 半楕円形の3種類を選び, 電力損と局所表面インピーダンスを計算する.形状や溝の深さによる特性の違いを観察し, 電磁界分布を参照しながら数値結果の振舞いを物理的に考察する.

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Language：Japanese   Publisher：一般社団法人電子情報通信学会  

細線の集合で形成した同軸ケーブルに対する内外導体の実効半径の近似式を求めた.これにより, 同心円断面のケーブルに対する従来の特性インピーダンスの公式がそのまま利用できるようになった.数値解析結果と比較し, 提案式がよい精度をもつことを確認した.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：E M W PUBLISHING  

The present paper concerns the design, numerical analysis, and measurement for simple metal-plate lens structures. The power of electromagnetic waves can be concentrated by arranging. at strips parallel to one another and adjusting the transverse and longitudinal length of the waveguide regions. The simple designing procedures are described for the lenses with plane, concave, and convex profiles. These steps are practically applied to construct the lenses for the X band. In order to discuss the dependence of focusing properties on the lens and source types, we numerically analyze the scattering problems using the integral equations combined with the moment method. The lenses are made up by aluminum plates, and the field amplitude in the transmission region is measured. We confirm the formation of the focus near the design point.

DOI： 10.2528/PIER05011401

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Language：Japanese   Publisher：電気学会  

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

DOI： 10.1109/MMET.2002.1106941

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Language：Japanese   Publisher：一般社団法人電子情報通信学会  

任意形断面をもつ導体伝送線路の交流実効抵抗とインダクタンスを, 断面を多数の小領域に分割してそれぞれをワイヤ要素に置き換えるいわゆるワイヤモデルを用いて計算する.このために複数本の円形断面ワイヤからなる伝送線路に対して, 電流密度分布に関する積分方程式を導き, モーメント法により連立1次方程式に帰着させる手順を示す.数値計算では, まず孤立導体及び単純な平行2線・平行3線のワイヤ伝送路のインピーダンス特性について物理的に詳しく検討する.その後, 任意形断面導体の例としてマイクロストリップ線路を取り上げ, 本解析法による結果が他の手法によるものとよく一致することを示し, その有効性を実証する.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

The problems of a plane wave scattering from multilayered resistive strip grating embedded in a dielectric slab without and with an impedance plane and multilayered perpendicularly crossed resistive strip grating in free space have been analyzed in order to investigate the absorption and scattering characteristics of resistive gratings. Each of considered problems was converted into a set of integral equations, which were solved by the moment method with appropriate basis functions to ensure a fast convergence. It has been verified that the obtained solutions are very efficient over a broad range of parameters of the incident wave and considered gratings.

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DOI： 10.2528/PIER99102801

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

An accurate and efficient numerical solution is presented for a two-dimensional electromagnetic wave scattering from a multilayered resistive strip grating embedded in a dielectric slab. Both E- and H-waves are treated. The problem is formulated into a set of integral equations, which is solved by the moment method accompanied by a regularization procedure. The resultant set of linear algebraic equations has the form of the Fredholm second kind, and therefore yields stable and accurate numerical solutions. The power distribution is computed for several grating parameters. Attention is paid to seek a set of parameters that maximizes absorption in the strips. The low frequency approximate formulas are also derived. This analysis would be useful in designing electromagnetic wave absorbers.

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Language：English   Publisher：Kumamoto University  

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Language：Japanese   Publisher：一般社団法人電子情報通信学会  

円柱導体集合の交流実効抵抗を積分方程式にモーメント法を併用して精密に数値解析した.円柱の太さは共通とするが, その配置および集合の直列グループへの分割数は任意とする.種々の外形をもつ集合に対して交流実効抵抗を計算することにより, 近接効果の影響を詳しく調べたて計算値の一部は他の解法および実測値と比較し, よく一致する結果を得た.機器設計における本解法の適用例として偏向ヨークの水平偏向コイルをとり上げ, 使用周波数帯における損失電力を種々のパラメータに対して求めた.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

An accurate and efficient numerical solution is presented for the two-dimensional electromagnetic wave scattering from multilayered resistive strip gratings embedded in a dielectric slab. The problem is formulated into the, set of integral equations, which is solved by moment method with the regularization ion procedure. Numerical computations are carried out for both scattered and absorbed powers.

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Language：English   Publishing type：Research paper (international conference proceedings)   Publisher：IEEE  

An accurate and efficient numerical solution is presented for the two-dimensional electromagnetic wave scattering from multilayered resistive strip gratings embedded in a dielectric slab. Both E- and H-waves are treated. The problem is formulated into the set of integral equations, which is solved by moment method accompanied with, the regularization procedure. The resultant set of linear algebraic equations has the form of Fredholm second kind, and therefore yields stable and accurate numerical solutions. Power distributions computed far several grating parameters are presented. We paid special attention to maximizing the absorption into the strips as this analysis to be useful in designing electromagnetic wave absorbers.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：VSP BV  

An accurate and efficient numerical solution is presented for the two-dimensional electromagnetic wave scattering from multilayered resistive strip gratings. Both E- and H-waves are treated. The method is based on the integral equations combined with the moment method with regularization procedure. The numerical experiment reveals the criteria for the truncation numbers. The reflected, transmitted, and absorbed powers are computed for various grating parameters and frequencies. Special attention is paid to maximizing the absorption into the strips, and thereby the relative absorbed power amounts to more than 90%.

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

An accurate numerical solution is presented for the electromagnetic scattering from a double strip grating, where the strip planes are each supported by a dielectric slab. This structure is a model of polarization diplexers. The direction of propagation and the polarization of the incident plane wave are arbitrary. We derive a set of singular integral equations and solve it by the moment method, where the Chebyshev polynomials are successfully used as the basis and the testing functions. By numerical computations we examine the dependence of the diplexing properties on grating parameters in detail. The cross-polarization characteristics at skew incidence are also referred. From these results we construct an algorithm for the design of polarization diplexers.

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Language：Japanese   Publisher：電気学会  

DOI： 10.1541/ieejfms1990.113.3_191

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：VSP BV  

An accurate numerical solution for the electromagnetic scattering from an infinite strip grating is presented, where the strips are loaded with a symmetrical pair of dielectric slabs. The direction of propagation and the polarization of the incident plane wave are arbitrary. The boundary value problem is reduced to a solution of singular integral equations, which are discretized by an application of the moment method. Numerical computations are performed mainly for the purpose of designing polarization diplexers. Dependence of diplexing characteristics on grating parameters is examined in detail. Appearance of cross-polarized field at skew incidence is referred.

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DOI： 10.1541/ieejfms1990.113.3_205

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

An accurate numerical solution is presented for the electromagnetic scattering from infinite strip gratings attached to both sides of a dielectric slab. This structure is a model of polarization discriminating devices. The period of the strips is common to both planes, but the widths and the axes may be different. The direction of propagation and the polarization of an incident plane wave are arbitrary. We derive a set of singular integral equations and solve it by the moment method, where the Chebyshev polynomials are successfully used as the basis and the testing functions. This method is accurate and effective owing to the incorporation of the edge condition and the decomposition of the kernel functions into the singular and the regular parts. Numerical calculations are carried out for the purpose of designing polarization discriminators, and it is shown that the band width is widened by decreasing the permittivity of the slab. The cross-polarization characteristics at skew incidence are also discussed.

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Language：English   Publisher：Kumamoto University  

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Language：English   Publisher：Kumamoto University  

CiNii Books

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：VSP BV  

An accurate numerical solution for the electromagnetic scattering from a periodic array of a finite number of conducting strips is presented, where the incident plane wave propagates in an arbitrary direction. Both TM and TE polarizations are treated. First, the boundary value problem is formulated into the solution of a set of Fredholm integral equations of the first kind with singular kernels. Then it is regularized to a set of the second kind equations which is numerically solved by the moment method. The present method is much more effective than the moment solution of the first kind equations. This is because the kernel functions of the resulting second kind equations are bounded and smooth, and because the edge condition is automatically taken into account in the course of the regularization. Some numerical examples are shown for the total scattering cross-sections, surface current distributions, and the far-zone scattered fields. The near zone fields are compared with the experimental data.

Web of Science

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CiNii Books

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Language：English   Publishing type：Research paper (scientific journal)   Publisher：VSP BV  

Web of Science

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Language：Japanese   Publisher：電子通信学会  

CiNii Books

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Language：Japanese   Publisher：電子通信学会  

CiNii Books

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

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Language：Japanese   Publishing type：Internal/External technical report, pre-print, etc.  

J-GLOBAL

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

CiNii Books

J-GLOBAL

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

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Language：English   Publishing type：Research paper, summary (international conference)  

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：The Institute of Image Information and Television Engineers  

The characteristics of scattering and absorption of electromagnetic waves by a two-dimensional grating of thin noble metal disks are obtained by numerical analysis. A set of integral equations for the unknown surface current density on the disks are derived by generalized boundary conditions and solved numerically using the method of moments. We apply the transverse magnetic field of the circular waveguide modes as the basis function. The reflected, transmitted, and absorbed powers are computed for several grating parameters.

CiNii Books

J-GLOBAL

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：The Institute of Image Information and Television Engineers  

Much attention has been attracted for solar power generation. For reduction of the generation cost, amorphous silicon solar battery without the worry of the lack of materials attracts attention unlike a conventional crystal type. Recently, electromagnetic scattering from arrays composed of periodic dielectric bodies have attracted more and more attention because they are important as highly efficient for solar panels. We analyzed the three dimensional problem numerically by an application of the modal expansion method. In conclusion, we calculated total scattering cross section and absorption cross section for confirming the reinforcement of the electric field derived from surface plasmon resonance and lattice resonances.

CiNii Books

J-GLOBAL

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)   Publisher：The Institute of Image Information and Television Engineers  

Scattering and absorption property of electromagnetic waves by a very thin semi-infinite plate of noble-metal is obtained by numerical analysis using generalized boundary conditions. To investigate directly the behavior of electromagnetic waves at the endpoints when light waves is incident on this plate, we solve semi-infinite problem using the Wiener-Hopf method.

CiNii Books

J-GLOBAL

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Language：Japanese   Publishing type：Research paper, summary (national, other academic conference)  

J-GLOBAL

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Authorship：Lead author   Publishing type：Research paper, summary (national, other academic conference)  

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：一般社団法人映像情報メディア学会  

We present an idea of grating-based plasmon biosensor utilizing phase detection to realize high resolution in finding a refractive index of a material put on the surface of a metal grating. Assuming the resolution in phase detection to be 2.5×10^<-2> degrees, we estimate the resolution of the biosensor as 7.5×10^<-7> refractive index units. We also discuss the possible improvement to realize a predicted superior limit of resolution around 10^<-8>.

CiNii Books

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Language：Japanese  

CiNii Books

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Language：Japanese  

CiNii Books

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Authorship：Corresponding author   Publishing type：Research paper, summary (national, other academic conference)  

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese  

CiNii Books

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Language：Japanese  

CiNii Books

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Language：Japanese   Publisher：一般社団法人電子情報通信学会  

Impedance of a conductor with an rectangular cross section are computed by the cross section is subdivided into small segments. To this end, an integral equation is derived of the current density distribution at subdivided cross sections. This equation is transformed to a set of linear simultaneous equations by the method of moments. In the numerical calculations, the impedance characteristics that considered influence of substrate loss are discussed in physically for an isolated conductor.

CiNii Books

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

An accurate numerical solution is presented and applied to the electromagnetic scattering by a set of dielectric spheres with various diameters and positions. The method of modal expansion is for solving boundary value problems using the mode matching method, where the electromagnetic fields in the air and dielectric regions are approximated using Shcelkunoff Bessel function and Stratton vector spherical wave functions, respectively. The treated structure is a fundamental model of modeling millimeter wave scattering by realistic distributed raindrops. Introduce QR decomposition based on Gram-Schmidt orthoganalization to reduce the computation time.

CiNii Books

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Language：Japanese   Publisher：映像情報メディア学会  

CiNii Books

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CiNii Books

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CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

The present report concerns the design, numerical analysis, and measurement for simple metal-plate lenses available in basic laboratories. Electromagnetic waves c.an be focused by forming waveguide regions using less than 20 parallel strips, and adjusting the width or interval of them. A simple design method is proposed and practically used to construct lenses for the 10 GHz band. In treating the integration equations, we adopted the general and exact solution for linear functional equations which one of the authors established. Numerical computations revealed how the characteristics depend on the structure and excitation. We made an experiment using aluminum plates, and checked the usefulness of the present structure by comparing the theoretical and measured values.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

We extend the applicability of the conventional mode matching method for the electromagnetic scattering from a dielectric sufrace with two dimensional periodicity to the case of deep grooves. The groove region is devided to several shallow layers, in which the field is expressed by a superposition of up- and down-going plane waves constructed from mode functions. This treatment improves the approximation efficiency compared with the conventional method that uses one way plane waves in respective air and dielectric regions. While the description is limited to the pyramidal shape, minor exchange enables to apply to other dielectric types such as sinusoidal one.

CiNii Books

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Language：Japanese  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

We model rough metal surfaces, in the simplest manner, by periodic metallic grooves of infinit length. This two dimensional problem is analyzied by the equivalent source method. The direction of current is both perpendicular and parallel to the grooves, which are the cases of H- and E-waves, respectively. The power loss char- acteristics are computed for three types of groove cross sections: rectagular, parbolic, and triangular. We compare the results and investigate the reason of difference by taking account of the current distributions.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

An equivalent circuit parameter is obtained for a one-dimensional periodic grating composed of dielectric cylinders with circular cross section at plane wave incidence by the use of Lewin's algorithm. The boundary condition on the cylinder surface leads us to a set of linear algebraic equations for the effective polarization current and the dipole moments of the longitudinal and transeverse electric current. Band gap characteristics of photonic crystals are easily computed by loading the above equivalent reactance periodically in the transmission line model.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

We calculate the AC effective resistance and inductance of conducting transmission lines having an arbitrary cross section shapes using so-called the wire model. In this method we divide the cross section into a lot of subdomains and replace each of them by a wire element. To this end, we lead a set of integral equations for the current density distribution on transmission lines composed of conducting wires, and apply the moment method to derive a set of simultaneous linear equations. The numerical computations are carried out for isolated conductors and microstrip lines. We demonstrate the effectiveness of the present analysis by showing that the results agree well with the solutions by other techniques.

CiNii Books

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

The characteristics of the H-plane Y-junction ferrite circulator of a rectangular waveguides are analyzed by the mode matching method in the sense of least squares. The cross section of the ferrite and dielectric cylinders is numerically treated by the Fourier series. It is demonstrated that the introduction of the smoothing procedure is effective to reduce the computational error. The reflection, insertion, and isolation losses were computed for several cross sections of the ferrite and dielectric cylinders. It is shown that the partial control of the width and center of the operating frequency band is possible by the depression of cylinder sides and the loading of dielectric material.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

We analyzed the H-plane Y-junction circulators of rectangular waveguides by using the mode matching method based on the least squares. This technique can easily treat the case where the cross section of the ferrite cylinder is deformed from a circle. The dependence of the norm and energy errors on the truncation numbers is examined when the cross section is circular and quasi-triangular. The frequency characteristics of the circulator, i.e., the reflection, insertion, and isolation losses are discussed.

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

An accurate numerical analysis is presented for the AC effective resistance and the inductance of imperfectly conducting wire transmission lines. The number and the allocation of the wires are arbitrary. The analysis is based on integral equations combined with the moment method. The numerical results are shown for the resistance and inductance of two-wire and three-wire lines, and their behavior is considered physically in view of the skin and proximity effects. The present technique is also applied to the microstrip lines and obtained good agreement with the results by other methods.

CiNii Books

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：English  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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CiNii Books

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CiNii Books

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CiNii Books

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Language：English   Publisher：The Institute of Electronics, Information and Communication Engineers  

The plane wave scattering from resistive strip gratings has been analyzed by the spectral Galerkin procedure and the method of the Riemann-Hilbert problem. The present report constructs the integral equation solution to thid canonical problem as a preparation for treating more complicated geometries.

CiNii Books

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Language：Japanese  

CiNii Books

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Language：Japanese  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

An accurate numerical treatment is proposed for the dispersion characteristics of disk-type artificial dielectrics. Two approaches based on the moment method is described for solving the homogeneous integral equation for the current density on the disk. As a preparation of accurate numerical computations, the approximate results for the relative effective permittivity and the dispersion curves are presented.

CiNii Books

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Language：English  

CiNii Books

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Language：Japanese  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

CiNii Books

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Language：Japanese   Publisher：The Institute of Electronics, Information and Communication Engineers  

An accurate numerikal solution is presented for the excitation characteristics of guided modes of a slab waveguide at a plane wave incidence,where a strip-type grating coupler is used.The problem is twodimensional and both TE and TM modes are treated.We derive a set of singular integral equations and solve it by the moment method,where the Chebyshev polynomials are successfully used as the basis and the testing functions.Numerical calculations are carried out under the condition that the error on the optical theorem is less than 0.01%.The calculations predict that the efficiencies of the first even mode at its maximum are 48% and 55% in the TE and TM cases,respectively.

CiNii Books

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Language：English  

We develop a numerical solution to the scattering problem with regard to perpendicularly crossed multi-layered strip gratings. This structure is regarded as a microscopic model of electromagnetic wave absorbing sheet of the fiber type. The boundary value problem is formulated into the set of integral equations, which is discretized to the linear equations by applying the moment method. Numerical computation is carried out for the distribution of the incident power to the reflected, transmitted, and absorbed powers. The absorbing rate exceeds 94% by a proper choice of grating parameters. The equivalent circuit parameters of the crossed resistive grating is also obtained.

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Language：English  

We develop a numerical solution to the scattering problem with regard to perpendicularly crossed multi-layered strip gratings. This structure is regarded as a microscopic model of electromagnetic wave absorbing sheet of the fiber type. The boundary value problem is formulated into the set of integral equations, which is discretized to the linear equations by applying the moment method. Numerical computation is carried out for the distribution of the incident power to the reflected, transmitted, and absorbed powers. The absorbing rate exceeds 94% by a proper choice of grating parameters. The equivalent circuit parameters of the crossed resistive grating is also obtained.

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Language：Japanese  

An accurate numerical analysis is presented for the AC effective resistance and the inductance of imperfectly conducting wire transmission lines. The number and the allocation of the wires are arbitrary. The analysis is based on integral equations combined with the moment method. The numerical results are shown for the resistance and inductance of two-wire and three-wire lines, and their behavior is considered physically in view of the skin and proximity effects. The present technique is also applied to the microstrip lines and obtained good agreement with the results by other methods.

researchmap

Language：Japanese  

An accurate numerical analysis is presented for the AC effective resistance and the inductance of imperfectly conducting wire transmission lines. The number and the allocation of the wires are arbitrary. The analysis is based on integral equations combined with the moment method. The numerical results are shown for the resistance and inductance of two-wire and three-wire lines, and their behavior is considered physically in view of the skin and proximity effects. The present technique is also applied to the microstrip lines and obtained good agreement with the results by other methods.

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Language：Japanese  

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Language：Japanese  

We calculate the AC effective resistance and inductance of conducting transmission lines having an arbitrary cross section shapes using so-called the wire model. In this method we divide the cross section into a lot of subdomains and replace each of them by a wire element. To this end, we lead a set of integral equations for the current density distribution on transmission lines composed of conducting wires, and apply the moment method to derive a set of simultaneous linear equations. The numerical computations are carried out for isolated conductors and microstrip lines. We demonstrate the effectiveness of the present analysis by showing that the results agree well with the solutions by other techniques.

researchmap

Language：Japanese  

We analyzed the H-plane Y-junction circulators of rectangular waveguides by using the mode matching method based on the least squares. This technique can easily treat the case where the cross section of the ferrite cylinder is deformed from a circle. The dependence of the norm and energy errors on the truncation numbers is examined when the cross section is circular and quasi-triangular. The frequency characteristics of the circulator, i.e., the reflection, insertion, and isolation losses are discussed.

researchmap

Language：Japanese  

We analyzed the H-plane Y-junction circulators of rectangular waveguides by using the mode matching method based on the least squares.This technique can easily treat the case where the cross section of the ferrite cylinder is deformedfrom a circle. The dependence of the norm and energy errors on thetruncation numbers is examined when the cross sectin is circular and quasi-triangular. The frequency characteristics of the circulator,i.e.,the renection, insertion, and isolation losses are discussed.

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Language：Japanese  

We extend the applicability of the conventional mode matching method for the electromagnetic scattering from a dielectric sufrace with two dimensional periodicity to the case of deep grooves. The groove region is devided to several shallow layers, in which the field is expressed by a superposition of up- and down-going plane waves constructed from mode functions. This treatment improves the approximation efficiency compared with the conventional method that uses one way plane waves in respective air and dielectric regions. While the description is limited to the pyramidal shape, minor exchange enables to apply to other dielectric types such as sinusoidal one.

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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The plane wave scattering from resistive strip gratings has been analyzed by the spectral Galerkin procedure and the method of the Riemann-Hilbert problem. The present report constructs the integral equation solution to thid canonical problem as a preparation for treating more complicated geometries.

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Language：English  

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Language：Japanese  

The present report concerns the design, numerical analysis, and measurement for simple metal-plate lenses available in basic laboratories. Electromagnetic waves c.an be focused by forming waveguide regions using less than 20 parallel strips, and adjusting the width or interval of them. A simple design method is proposed and practically used to construct lenses for the 10 GHz band. In treating the integration equations, we adopted the general and exact solution for linear functional equations which one of the authors established. Numerical computations revealed how the characteristics depend on the structure and excitation. We made an experiment using aluminum plates, and checked the usefulness of the present structure by comparing the theoretical and measured values.

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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Language：Japanese   Presentation type：Oral presentation (general)  

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An equivalent circuit parameter is obtained for a one-dimensional periodic grating composed of dielectric cylinders with circular cross section at plane wave incidence by the use of Lewin's algorithm. The boundary condition on the cylinder surface leads us to a set of linear algebraic equations for the effective polarization current and the dipole moments of the longitudinal and transeverse electric current. Band gap characteristics of photonic crystals are easily computed by loading the above equivalent reactance periodically in the transmission line model.

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Language：Japanese  

筆者らは有限枚の平板格子を付けた誘電体スラブに平面波が入射する散乱問題に対して,特異積分方程式による精密な数値解法を適用してきた.スラブの表面,内部中心に格子を置いた場合では,構造に応じた特定次数の導波モードの励振効率が約40%となった.本稿では任意に指定したモードとの結合を密にするため,格子を任意の深さで埋めた場合へ解析を拡張する.

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The characteristics of the H-plane Y-junction ferrite circulator of a rectangular waveguides are analyzed by the mode matching method in the sense of least squares. The cross section of the ferrite and dielectric cylinders is numerically treated by the Fourier series. It is demonstrated that the introduction of the smoothing procedure is effective to reduce the computational error. The reflection, insertion, and isolation losses were computed for several cross sections of the ferrite and dielectric cylinders. It is shown that the partial control of the width and center of the operating frequency band is possible by the depression of cylinder sides and the loading of dielectric material.

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Language：Japanese  

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Language：Japanese  

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We model rough metal surfaces, in the simplest manner, by periodic metallic grooves of infinit length. This two dimensional problem is analyzied by the equivalent source method. The direction of current is both perpendicular and parallel to the grooves, which are the cases of H- and E-waves, respectively. The power loss char- acteristics are computed for three types of groove cross sections: rectagular, parbolic, and triangular. We compare the results and investigate the reason of difference by taking account of the current distributions.

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2方向に周期的に並べた平板導体群,ならびに3方向に周期的な円板導体群は,レンズアンテナに応用が可能な人工誘電体として,その低周波領域における分散特性が解析的に求められてきた.これらの構造は,近年ふたたび関心が高まってきたフォトニックバンドギャップを生ずる結晶媒質の基本的なモデルとも考えられる.したがって共振領域や高周波領域に至るまで正確な分散特性を与える数値解析法を開発しておくことは重要である.本稿では筆者らが多重平板格子による電磁波散乱問題に対して用いてきた特異積分方程式法を,固有値問題に適用できるように変形する.

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Language：Japanese  

An accurate numerikal solution is presented for the excitation characteristics of guided modes of a slab waveguide at a plane wave incidence,where a strip-type grating coupler is used.The problem is twodimensional and both TE and TM modes are treated.We derive a set of singular integral equations and solve it by the moment method,where the Chebyshev polynomials are successfully used as the basis and the testing functions.Numerical calculations are carried out under the condition that the error on the optical theorem is less than 0.01%.The calculations predict that the efficiencies of the first even mode at its maximum are 48% and 55% in the TE and TM cases,respectively.

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An accurate numerical treatment is proposed for the dispersion characteristics of disk-type artificial dielectrics. Two approaches based on the moment method is described for solving the homogeneous integral equation for the current density on the disk. As a preparation of accurate numerical computations, the approximate results for the relative effective permittivity and the dispersion curves are presented.

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