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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

This paper proposes a spiral-shaped dispersive delay structure (Spiral-DDS) composed of vertically stacked spiral coils and vertical vias. This all-pass network architecture can produce a large group delay peak at a certain frequency in a few GHz range. Basic performance of the Spiral-DDS are studied theoretically, and the group delay with more than 6 ns was successfully generated by a compact multilayered architecture with dimensions of 6.0 x 6.0 x 1.18 mm (3). This paper also reports that the most of losses occurred in DDS comes from conductor loss, not from dielectric loss.

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記述言語：日本語   出版者・発行元：一般社団法人電子情報通信学会  

本研究では,2次元解析モデルを用いて金属ナノ開口から発生する表面プラズモンポラリトンについて検討を行う.FDTD法により得られた界分布と理論解析から求められる偶奇モードの界分布の重なり積分を求めることによりその評価を行う.

CiNii Books

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

The scattering from a phase change disk that is illuminated by an optical near field through a ridged-square nano-aperture was analyzed. A finite-difference time-domain (FDTD) method installed with motion equations of free electrons was used in the analysis and a three dimensional disk structure was taken into consideration. The far-field scattering patterns from the phase change disk were analyzed and the sum-signal output through a condenser lens was calculated. The crosstalk between plural marks and the readout characteristics of mark trains were investigated.

DOI： 10.1587/transele.E95.C.1110

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

DOI： 10.1541/ieejeiss.132.1310

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：WILEY-BLACKWELL  

A compact ultra-widehand (UWB) bandpass filter using a multilayered structure is proposed. The proposed filter is composed of a pair of parallel plates, a meander line, and a thin conductor column that connects the parallel plates. The fabricated filter has a small size of 5 X 6 X 1.818 mm(3) that amounts to 0.19 lambda(g) x 0.22 lambda(g) x 0.07 lambda(g), where lambda(g) is the guided wavelength at the center frequency of the passband (6.95 GHz). CIWB bandpass characteristics from 1.9 to 12.0 GHz with two attenuation poles at 0.4 and 12.8 GHz were achieved. Experimental results are in good agreement with the numerical ones that are obtained from a simulation and an equivalent circuit. Flat group delay characteristics in the wide frequency range are also shown. (C) 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 53:557-559, 2011: View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.258

DOI： 10.1002/mop.25816

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

A comb-line filter with a coupling capacitor in the ground plane is proposed. The filter consists of two quarter-wavelength microstrip resonators. A coupling capacitor is inserted into the ground plane in order to build strong coupling locally along the resonators. The filtering characteristics are investigated through numerical simulations as well as experiments. Filtering characteristics that have attenuation poles at both sides of the passband are obtained. The input susceptances of even and odd modes and coupling coefficients are discussed. The filters using stepped impedance resonators (SIRs) are also discussed, and the effects of the coupling capacitor for an SIR structure are shown. © 2011 Toshiaki Kitamura.

DOI： 10.1155/2011/919240

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

Scattering characteristics of a domain wall displacement detection (DWDD) disk with a control layer were investigated by finite difference time domain (FDTD) analysis DWDD is one of the high density storage technologies of magneto optical (MO) disks and the control layer is used to suppress ghost signals due to a rear process The effects of the control layer on the scattering characteristics were studied

DOI： 10.1587/transele.E93.C.1713

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

Readout characteristics of a near-field optical disk with an acute-edged metallic nano-aperture were investigated. The electromagnetic field distributions of the near field around the aperture were analyzed, and the far-field scattering of the waves transmitted through the phase change disk was calculated by finite-difference time-domain method into which motion equations of free electrons were incorporated. Adjusting the edge angle of the aperture increased the field intensity of near-field light. The influence of the edge angle on output through the recorded mark was also investigated. It was found that there is an optimum edge angle that differs depending on the aperture width.

DOI： 10.1587/transele.E93.C.1474

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

This paper proposes a super-compact dual-band Wilkinson power divider composed of two multi-layered (ML) composite right/left-handed (CRLH) transmission lines (TL). Theoretical analysis based on the finite element method shows that the divider with dimensions of 7.6 x 5.0 x 2.85 mm(3) has two operation bands from 3.7 GHz to 5.1 GHz in a left-handed branch and from 7.2 GHz to 8.0 GHz in a right-handed branch, with corresponding to the fractional bandwidth of 31.8% and 10.5%, respectively. Experimental verification is also carried out for the prototype model. This new architecture, incorporated with ML CRLH technique, is quite useful to realize highfunctionality along with significant size-reduction.

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記述言語：日本語   出版者・発行元：一般社団法人 電気学会  

In this paper we propose a new type of comb-line filter which consists of a couple of meander-shaped quarter-wavelength microstrip resonators. We investigate the filtering characteristics through FD-TD simulations. Furthermore, we design the filter and discuss its filtering characteristics through experiments as well as numerical simulations. It is found that this filter realizes a considerable reduction in the size of structure and sharp bandpass characteristics with multiple attenuation poles around the passband.

DOI： 10.1541/ieejeiss.125.1596

CiNii Books

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記述言語：英語   掲載種別：研究論文（学術雑誌）  

This paper proposes a new type of multi-stratified comb-line filters of narrow pass band utilizing conductor-backed coplanar waveguides. It is shown through numerical simulations by means of FD-TD method that the filtering characteristics can be controlled effectively by introducing a grounding conductor with a window between the coupled two resonators. It is demonstrated that, by changing the dimensions of the window on the grounding conductor, we can change, without affecting the odd mode, the input susceptance of the even mode independently and that we can adjust the frequency of attenuation pole. An interesting feature of this filter is that an additional window on the grounding conductor makes another attenuation pole appear around the passband. © 2003, The Institute of Electrical Engineers of Japan. All rights reserved.

DOI： 10.1541/ieejeiss.123.875

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

In this paper, a dual-plane comb-line filter having plural attenuation poles is proposed. We investigate the filtering characteristics from both experiments and numerical simulations by means of the finite-difference time-domain method. It is shown that this filter has attenuation poles just above, as well as below the passband and that intersections between the curves of input susceptance of the even and odd modes agree with the attenuation-pole frequencies. Furthermore, it is demonstrated that, by changing the position of the metal pin, which connects two resonators, we can change the input susceptance of the odd mode alone and, hence, regulate the attenuation-pole frequencies.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

We propose a new element containing a two-mode nonlinear waveguide consisting of Kerr-like material for all-optical logic circuits. The proposed element, incorporated into the Mach-Zehnder interferometer, functions like a phase shifter. Although the optical waves propagating in the proposed element are monochromatic and identical in polarization, its function is insensitive to the relative phase difference between the incident beams. Using this element, we can realize various logic functions. In this paper, we demonstrate such logic circuits as inverters, distributors, and AND gates.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

This paper proposes an optical power limiter composed of serially connected two tapered velocity couplers consisting partly of nonlinear material. The method of device designing is explained and it is exemplified that the optical output can be regulated stably to a prescribed value over a wide range of optical input. The del ice performance is: simulated by means: of FD-BPM algorithm.

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記述言語：英語   掲載種別：研究論文（国際会議プロシーディングス）   出版者・発行元：IEEE  

This paper proposes a novel multi-stage dual-plane comb-line filter having plural attenuation poles just below and above the passband. As this filter has such a structure that two quarter-wavelength step impedance resonators are placed face-to-face beyond the substrate on each filter block, the mutual coupling between adjacent blocks are small and the optimisation on each block can be done independently. High performance filters up to 4-stages are demonstrated both theoretically and experimentally.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

Optical logic gates for OR, AND, NOT, and NOR operations in waveguides consisting of nonlinear material are numerically investigated by means of FD-BPM (Finite Difference Beam Propagation Method). The proposed devices are designed utilizing the self-routing characteristics of nonlinear X-crossing structures when they are operated with one input beam or two. The numerical simulations show that the proposed structures can favorably be applied to optical data processing and computing as fundamental logic gates.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

We examine crossing waveguides with three channels consisting of nonlinear material by means of FD-BPM (Finite Difference Beam Propagation Method). Specifically, we investigate how the insertion of a multimode waveguide into the crossing section of both 1x3 and 2x3 structures influences the switching characteristics of output power. We then confirm that these structures can be favorably applied to a wide variety of all-optical devices for integrated optics such as intensity-dependent optical switches, optical power distributors and so on.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

The influence of loaded capacitance on the resonant frequency of a triplate-type strip resonator is investigated through numerical simulations by means of the finite-difference time-domain (FDTD) method. This type of resonator is one of the basic components of very small high-dielectric stripline filters, named laminated planar filters. Numerical results of resonant frequencies are compared with experimental results and found to be in excellent agreement, which circumstance ensures that the FD TD method can be applied to the characterization of a wide range of laminated planar microwave devices including resonators and filters. It is also found that the resonant frequency is directly related to the square root of its line capacitance when the resonator is regarded equivalently as a series LC circuit.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

The influence of ground terminal shape on the resonant frequency of a microstrip resonator is investigated through numerical simulations and experiments, Resonators are one of the basic components of very small high-dielectric stripline filters, named the laminated planar filter. The resonant frequencies are calculated by means of the finite-difference time-domain (FDTD) method and compared with experimental results, It is also shown that the resonant frequency is directly related to the square root of its line inductance when the resonator is regarded equivalently as a series LC circuit.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

Investigated is a guided-wave device for dividing optical power into three equal parts. The device fundamentally consists of a three-waveguide tapered-velocity coupler which is designed to operate under the adiabatic condition. Field distributions of the local normal modes along the coupler explain basic principles of the device. Its performance is confirmed through numerical simulations by means of finite difference beam propagation method.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

A new type of guided-wave polarization splitter is proposed for the operation at optical Frequencies. The basic structure of the device is a bifurcating waveguide fabricated in a uniaxial crystalline material such as LiNbO3. The splitting behavior of optical waves into two waves with mutually perpendicular directions of polarization by an optically anisotropic material is utilized in the branching section of the present polarization splitter. One of the conspicuous features of the device is free of any electrical control via the electro-optic effects. Some numerical results obtained with the finite difference beam propagation method indicate that extinction ratios better than 20 dB are possible of realization for both TE and TM modes.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

A two-waveguide tapered velocity coupler is presented for a variable divider of optical beams. The coupler consists of one tapered slab waveguide in dimension and the other slab waveguide with a constant film thickness. It is assumed that the device is fabricated on a LiNbO3 substrate, with a push/pull external electric field parallel with the optic axis applied only in the film regions of the coupler. Various numerical simulations through the finite difference beam propagation analysis show that a wide range of dividing ratios from - 15 dB to 15 dB or more can be achieved with considerably small values of driving-voltage electrode-length product and that the dividing characteristics are stable over a wide range of frequencies.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

We investigate a three-waveguide tapered velocity coupler which consists of a uniform linear, tapered linear and tapered nonlinear slab waveguide. The coupling characteristics depending on the gap width between the waveguides and sloping angle of the tapered waveguides are analyzed by means of the finite difference method. The numerical results show that with realistic structural parameters flat output power characteristics can be obtained over a wide range of input power. It is found that it is possible to use the present structure as a power limiter.

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記述言語：英語   掲載種別：研究論文（学術雑誌）   出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG  

This paper presents a theoretical study on transmission properties of bent optical waveguides of uniaxial anisotropic material. The waveguiding structure consists of two parallel straight slab waveguides connecting by an oblique section. By arranging the direction of the optical axis in the oblique section so that the wave normal always points to the same direction throughout the waveguiding structure, low loss transmission can be realized. The analysis of wave propagation through the structure is based on the finite difference beam propagation method. Numerical results indicate that by optimally arranging the direction of the optical axis in the oblique section power coupling coefficients better than 95% can be obtained for any tilt angle of the oblique section when the tilt angle is smaller than 2 degrees. Some held distributions are also presented along the waveguiding structure.

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記述言語：英語   出版者・発行元：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC  

This paper presents full-wave analysis of the cylindrical striplines and the cylindrical microstrip lines utilizing the finite difference time-domain method in a circular-cylindrical coordinate system. Numerical results on the normalized characteristic impedance are in good agreement with the available results. Furthermore, the junctions of the coaxial transmission line and the cylindrical microstrip line are analyzed to show the usefulness of this method.

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記述言語：日本語   出版者・発行元：一般社団法人電子情報通信学会  

分散性媒質に適用できる差分時間領域法(frequency-dependent finite-difference time-domainmethod)を用いた高温超伝導コプレーナ線路の解析について報告する.2流体モデルから得られる超伝導体の複素導電率を差分時間領域法に組み込むことにより解析する.LaAlO_3基板上にYBCO薄膜で形成された高温超伝導コプレーナ線路を基板の誘電損を考慮して解析し,Kesslerらの結果と比較して本手法の有効性を確認する.超伝導体厚を変化させた場合の検討や,常伝導コプレーナ線路との特性の比較を行い,その低損失性および低分散性を明らかにする.また,導波路形光変調器の進行波形電極として高温超伝導線路を用いることが提案されている.本論文では,LiNbO_3基板上にYBCO薄膜で形成された高温超伝導コプレーナ線路について基板の異方性や損失をも考慮してその特性を明らかにし,優れた進行波形電極が構成できることを示す.

CiNii Books

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記述言語：日本語   出版者・発行元：一般社団法人電子情報通信学会  

GaAs基板上に,金属・絶縁膜を積層化し,これらの層間・層上にマイクロ波伝送線路や回路素子を配置する構造の薄膜マイクロストリップ回路の提案がなされており,回路の小形化,新しい回路構成の実現,設計性の向上が図られることが示されている.一方,3次元構造に対する汎用的な解析法の一つとして差分時間領域法が注目を浴びており,かなり複雑な解析対象まで扱えることが示されている.しかし,従来の差分時間領域法においては,ほとんどの場合,導体は厚みなしの完全導体として扱われており,薄膜マイクロストリップ線路のように線路寸法に比べて導体厚が無視できない場合には適用できない.そこで本研究では,実際的なモデルとして,導体厚を考慮し,その損失を含めた定式化を行うとともに,導体部分では導体厚より十分小さな離散間隔とし,また,電磁界分布の変化の緩やかなところでは離散間隔を大きくし,必要な計算機の主記憶容量の削減,ならびに計算時間の短縮を図った.いくつかの形状の薄膜マイクロストリップ線路について解析を行い,線路定数の周波数特性,ならびに電磁界分布,ポインチング電力分布を求め,本手法の妥当性ならびに適用性を示す.

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記述言語：日本語   出版者・発行元：一般社団法人電子情報通信学会  

モノリシックマイクロ波集積回路(MMIC)の小形化,高集積化を目的とした多層化MMICの提案がなされており,新しい回路構成の実現,設計性の向上が図れることが示されている.多層化MMICを用いることによって回路の積層化が可能であり,回路サイズをより小形化できるが,回路の積層化に伴って上下線路間のクロストークを定量的に評価することが重要になってくる.従来,マイクロストリップ線路交差部の解析のほとんどは2線路が直角に交差している場合について行われたものであるが,本研究では任意座標系に対して適用できる差分時間領域法(FD-TD法)を用いて,2線路が任意の角度で交差している場合のクロストークについて解析を行う.まず,任意座標系に適用できるFD-TD法の概要を示す.次に単一のマイクロストリップ線路における本解析結果が,メッシュの形状に依存しないことを確認すると共に,任意角マイクロストリップ線路曲り部について,本解析結果が他文献の結果と一致することを示す.最後にマイクロストリップ線路の任意角立体交差部について解析を行い,sパラメータの規格化周波数特性,交差角依存性,ならびに線路間距離依存性を明らかにする.

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記述言語：日本語   出版者・発行元：電子情報通信学会エレクトロニクスソサイエティ  

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記述言語：英語   出版者・発行元：大阪府立大学  

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開催地：Shanghai, China  

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開催地：Shanghai, China  

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開催地：Montreal, Canada  

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開催地：Kuala Lumpur, Malaysia  

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開催地：Marrakesh, Morocco  

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開催地：Marrakesh, Morocco  

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開催地：Marrakesh, Morocco  

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開催地：Paris France  

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開催地：Paris France  

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開催地：Paris France  

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