Faculty Profiles - TOYOTA Yoshitaka

MISC - TOYOTA Yoshitaka

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A Simulation Method for EM Radiation from Power/Ground Plane of PCB by Using a Power Current Model, Vol.J86-B,No.2, pp.226-235

TAKAYAMA Keisuke, KINOSHITA Tomohiro, MATSUISHI Takuya, MATSUNAGA Shigeki, WANG Zhi Liang, TOYOTA Yoshitaka, WADA Osami, KOGA Ryuji, FUKUMOTO Yukihiro, SHIBATA Osamu

IEICE transactions on communications 86 ( 2 ) 887 - 887 2003.2

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

High-frequency currents flowing from power terminals of an IC/LSI onto power/ground planes of a digital printed circuit board can generate a great amount of electromagnetic noise. A powercurrent model of an IC/LSI for EMI simulation was proposed in our previous studies. A high-speed simulation algorithm of EM radiation due to resonance of the power/ground planes in a PCB was also developed. This paper describes the mechanism and quantitative effect of reducing high frequency currents on power/ground terminals by embedding a decoupling inductor and/or a bypass capacitor in an IC/LSI package. Furthermore, the internal decoupling effect on suppressing EMI radiated from the board is verified in both the simulations and measurements.

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Multipath structure for FSR expansion in waveguide-based optical ring resonator

IS Hidayat, Y Toyota, O Torigoe, O Wada, R Koga

ELECTRONICS LETTERS 39 ( 4 ) 366 - 367 2003.2

Language：English Publisher：IEE-INST ELEC ENG

A multipath structure of a ring resonator is proposed to expand the free spectral range. Simulation work indicates that the multipath ring resonator has 25 GHz-adjacent-channel crosstalk of -41 dB, maximum interchannel crosstalk of - 18 dB, and -1 dB bandwidth of 4 GHz for a typical expansion factor of 10. The results show the advantages of characteristics compared with a double-cavity ring resonator and a triple-coupler ring resonator.

DOI： 10.1049/el:20030276

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Aerosol Extinction Coefficient Continuously Measured with Polarized Mie Scattering Lidar

Iokibe Kengo, Toyota Yoshitaka, Wada Osami, Koga Ryuji

Memoirs of the Faculty of Engineering, Okayama University Vol.37, No.2, pp.89-97 ( 2 ) 89 - 97 2003

LSIの電源端子電流モデルのEMIシミュレーションへの適用

高山惠介, 木下智博, 松石拓也, 松永茂樹, 王志良, 豊田啓孝, 和田修己, 古賀隆治, 福本幸弘, 柴田修

電子情報通信学会論文誌B 2003

黄砂の観測を目的としたインターネットシステム上のレーザレーダ運用

古賀隆治, 五百旗頭健吾, 伊藤嘉則, 白川紘之, 豊田啓孝, 和田修己

計測自動制御学会中国支部学術講演会論文集 12th 2003

Effect of a rectangular field-stop for the laser rader receiving telescope

GOTOH Takanori, IOKIBE Kengo, TOYOTA Yoshitaka, WADA Osami, KOGA Ryuji

Technical report of IEICE. OPE 102 ( 448 ) 73 - 78 2002.11

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

A rectangular field-stop was employed in a polarization-discriminating lidar to suppress multiple scattering lights in the lidar return as well as to suppress background sunlight. In this paper, effect of the rectangular field stop for background light was investigated in terms of the signal to noise ratio. The effect for multiple scattering on the polarization coefficient as the result of measurement was also investigated for a rectangular field stop in comparison with circular one.

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Time response analysis of optical functional devices with multiple paths

ICHI-UMA Satoru, TOYOTA Yoshitaka, SYARIF HIDAYAT Iip, WADA Osami, KOGA Ryuji

Technical report of IEICE. OPE 102 ( 448 ) 67 - 72 2002.11

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

Various optical functional devices with multiple paths are studied. We have also studied the chracteristics of a double ring optical resonator as an optical functional device with multiple paths. In the double ring resonator, the difference of the propagation time exists between an inner ring and an outer ring. Therefore, we propose the analysis method in consideration of propagation delay time. This method was applied to our double ring resonator. It turns out that it is valid. In addition, the modulation analysis for double ring modulator was also performed with this method.

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Output-Load Dependency of Power Current Model of CMOS Driver Circuit

KINOSHITA Tomohiro, OSAKA Hideki, WADA Osami, TOYOTA Yoshitaka, KOGA Ryuji

IEICE technical report. Electromagnetic compatibility 102 ( 25 ) 25 - 30 2002.4

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

A macro-model of CMOS-LC/LSI for EMI simulation is discussed. To expand the power-current model, which the authors proposed, for I/O circuit, dependencies of internal impedance and RF power-current on load capacitance are experimentally investigated. As a result, variation of rise and fall current spectra coincides with the dependency of high and low state impedances, respectively. In addition, it is shown that the variation of current spectra has no direct correlation to the impedance difference due to the change of duty ratio of input signal.

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Experimental Verification of Common-Mode Excitation Model for PCB Having Partially Narrow Return Path

Watanabe Tetsushi, Wada Osami, Koga Ryuji, Toyota Yoshitaka, Miyashita Takuya

Memoirs of the Faculty of Engineering, Okayama University 36 ( 2 ) 83 - 89 2002

Application of segmentation method to analysis of power/ground plane resonance in multilayer PCBs

ZL Wang, O Wada, Y Toyota, R Koga

2002 3RD INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY 775 - 778 2002

Language：English Publisher：IEEE

The fast algorithm developed for calculating the resonant characteristics of the power/ground planes in multilayer PCBs, is extented to the case of that the pattern of the power/ground planes consists of several "segments" of rectangles, using the so-called sec,mentation method. Good agreements between the calculated and measured results have demonstrated the usefulness and accuracy of our fast algorithm and the segmantation method.

DOI： 10.1109/ELMAGC.2002.1177545

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Application of Transfer Matrix Method with Signal Flow-Chart to Analyze Optical Multi-Path Ring-Resonator

Hidayat Iip Syarif, Toyota Yoshitaka, Torigoe Osamu, Wada Osami, Koga Ryuji

Memoirs of the Faculty of Engineering, Okayama University 36 ( 2 ) 73 - 82 2002

Analytical simulation of radiated emission from power bus noise on PCB with linear macro-model of IC/LSI

Osami Wada, Zhi Liang Wang, Yukihiro Fukumoto, Yoshitaka Toyota, Ryuji Koga

XXVIth General Assembly of the International Union of Radio Science(URSI) 2002

Analysis of Cascade Microring-Resonator Type of Interleave Filter

Iip Syarif Hidayat, Yoshitaka Toyota, Osami Wada, Ryuji Koga

Asia-Pacific Conference on Communications (APCC 2002) 2002

Estimation of common-mode EMI caused by a signal line in the vicinity of ground edge on a PCB

T Watanabe, O Wada, Y Toyota, R Koga

2002 IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY, VOLS 1 AND 2, SYMPOSIUM RECORD 113 - 118 2002

Language：English Publisher：IEEE

The authors have developed an estimation method of common mode radiation from a PCB. A parameter named 'current division factor' explains a generation mechanism of the common mode. Rigorous analysis, instead of rough approximation, is required to calculate the factor for an asymmetric structure. A 2-dimentional static electric field analysis by the boundary, element method (BEM) is applied to this calculation, which requires less time than 3-dimentional simulations. EMI increases when the signal line comes close to the edge of ground pattern. The effect is evaluated with the simulation of the factor. The estimation agrees well with measurement within 1 dB.

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Radiated emission analysis of power bus noise by using a power current model of an LSI

Y Fukumoto, O Shibata, K Takayama, T Kinoshita, ZL Wang, Y Toyota, O Wada, R Koga

2002 IEEE INTERNATIONAL SYMPOSIUM ON ELECTROMAGNETIC COMPATIBILITY, VOLS 1 AND 2, SYMPOSIUM RECORD 1037 - 1042 2002

Language：English Publisher：IEEE

In this paper a power current model of an LSI, which was proposed at the last Symposium [5][6], was used for analysis of radiated emissions. The simulated radiation noise was compared with measurements by using an evaluation module that emulates an LSI. The simulation results showed good agreement with the measurement results. The effects of adding an internal decoupling capacitance and/or internal decoupling inductance to an LSI were also evaluated.

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Pulse Timing Control of Multiple Signal Interconnections for Reduction of EMI

Memoirs of the Faculty of Engineering, Okayama University 37 ( 1 ) 51 - 60 2002

岡山・福山における偏光ライダーによる対流圏同時観測

五百旗頭健吾, 香川直己, 豊田啓孝, 和田修己, 古賀隆治

応用物理学会学術講演会講演予稿集 63rd ( 3 ) 2002

Numerical analysis of optical ring resonators with double-ring structure to extend their FSR

TOYOTA Yoshitaka, HIDAYAT Iip SYARIF, TORIGOE Osamu, ICHI-UMA Satoru, WADA Osami, KOGA Ryuji

Technical report of IEICE. OPE 101 ( 504 ) 37 - 42 2001.12

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

A ring resonator with wider FSR is expected as an Add/Drop filter for the WDM system. In ring resonators, wider FSR is incompatible with less bending loss, because the FSR of a ring resonator is proportional to the inverse of its radius. Therefore the double-ring structure has been proposed to solve this problem. We analyzed this structure by the method based on the transfer matrix principle and signal flow chart. As a result, the FSR of more than 4THz and twenty times as wide as the one of single-ring structure is obtained. Moreover, the proper transmission characteristics are obtained for the structure of the input waveguide coupled with outer ring and output waveguide coupled with inner ring, and vice versa.

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A simple method for measuring the relative permittivity of printed circuit board materials

A Namba, S Wada, Y Toyota, Y Fukumoto, ZL Wang, R Koga, T Miyashita, T Watanabe

IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY 43 ( 4 ) 515 - 519 2001.11

Language：English Publisher：IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC

This paper presents a simple method to measure the relative permittivity of glass-epoxy printed circuit boards (PCBS). In this method, relative permittivity as a function of frequency is measured using an actual PCB. In order to estimate relative permittivity, the reflection coefficient is measured with a network analyzer. Relative permittivity is calculated by observing the frequencies of the resonant cavity modes. We show that the relative permittivity of a FR-4 sample decreases from 4.3 to 4.2 at frequencies from 300 MHz to 2 GHz.

DOI： 10.1109/15.974630

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Power current model of LSI/IC containing equivalent internal impedance for EMI analysis of digital circuits

Y Fukumoto, Y Takahata, O Wada, Y Toyota, T Miyashita, R Koga

IEICE TRANSACTIONS ON COMMUNICATIONS E84B ( 11 ) 3041 - 3049 2001.11

Language：English Publisher：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

This paper investigates a device model of the power current used for an LSI/IC. The model is proposed to analyze the power bus noise in digital circuit boards. This model is defined in the frequency domain and constructed with an equivalent internal impedance and an equivalent internal current source. Accordingly, the output current of the model is affected by power bus impedance, such as the capacitance of bypass capacitors and the parasitic inductance of power bus wiring. Therefore, the model is useful for analyzing the effectiveness of bypass capacitors and power bus wiring. The structure of equivalent internal impedance for a simple logic IC, such as 74HCXX, can be represented as an RLC series circuit. These parameters are identified by applying the least square method. To demonstrate the validity of the model, an experimental study was conducted. As a result, it was shown that the output current of the model corresponds to the measured current under a variety of power bus impedance levels within 6 dB.

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