研究者詳細 - 豊田　啓孝

MISC - 豊田　啓孝

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Connector Model for Use in Common-Mode Antenna Model Used to Estimate Radiation from Printed Circuit Boards with Board-to-Board Connector

Yuri Wakaduki, Tetsushi Watanabe, Yoshitaka Toyota, Kengo Iokibe, Liuji R. Koga, Osami Wada

IEICE TRANSACTIONS ON COMMUNICATIONS E99B ( 3 ) 695 - 702 2016年3月

記述言語：英語出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

A connector model expressed as an inductance is proposed for use in a previously reported common-mode antenna model. The common-mode antenna model is an equivalent model for estimating only common-mode radiation from a printed circuit board (PCB) more quickly and with less computational resources than a calculation method that fully divides the entire structure of the PCB into elemental cells, such as narrow signal traces and thin dielectric layers. Although the common-mode antenna model can estimate the amount of radiation on the basis of the pin configuration of the connector between two PCBs, the calculation results do not show the peak frequency shift in the radiation spectrum when there is a change in the pin configuration. A previous study suggested that the frequency shift depends on the total inductance of the connector, which led to the development of the connector model reported here, which takes into account the effective inductance of the connector. The common-mode antenna model with the developed connector model accurately simulates the peak frequency shift caused by a change in the connector pin configuration. The results agree well with measured spectra (error of 3 dB).

DOI： 10.1587/transcom.2015EBP3269

Web of Science

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配線へのコモンモード電流注入における電流プローブのモデル化とモード等価回路シミュレーション (環境電磁工学)

久米川公嗣, 五百旗頭健吾, 豊田啓孝

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 115 ( 427 ) 65 - 70 2016年1月

Suppression of mode conversion by installing bypass capacitor to power distribution network

Yoshitaka Toyota, Toshiki Mikura, Kengo Iokibe

IEEJ Transactions on Fundamentals and Materials 136 ( 1 ) 25 - 32 2016年1月

記述言語：日本語出版者・発行元：Institute of Electrical Engineers of Japan

In the modal-equivalent circuit derived from the view of the mode-decomposition technique, mode-conversion sources are placed at the interface where the imbalance factor of the transmission lines changes. In addition, the amount of the mode-conversion sources is proportional to not only the difference in the imbalance factor but also the magnitudes of the normal-mode voltage and the common-mode current at the same position. In this paper, therefore, the suppression of mode conversion from normal mode to common mode is experimentally examined by installing a bypass capacitor to power distribution network. The bypass capacitor helps reduce the normal-mode voltage in the vicinity of a connector on a test board where mode conversion occurs so that the common-mode current flowing a power-line cable and the electric field far from the test board are decreased. In fact, the mode conversion was most suppressed when the bypass capacitor is placed closest to the connector on the test board. Also, it was found that the mode conversion was suppressed by the capacitor installed to the power-line cable in the vicinity of the connector.

DOI： 10.1541/ieejfms.136.25

Scopus

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Analysis of side-channel information leaking behavior in cryptographic circuit using internal current source

Kengo Iokibe, Nobuhiro Tai, Hiroto Kagotani, Hiroyuki Onishi, Yoshitaka Toyota, Tetsushi Watanabe

IEEJ Transactions on Fundamentals and Materials 136 ( 6 ) 365 - 371 2016年

記述言語：日本語出版者・発行元：Institute of Electrical Engineers of Japan

Cryptographic circuits were analyzed regarding their side-channel information leaking behavior based on internal current source. Cryptographic circuits were implemented in an FPGA with registers arranged to demonstrate three known side-channel information leaking behaviors
(1) leakage is reduced by making Hamming distance (HD) at registers constant, (2)leakage increases with signal-to-noise ratio of side-channel traces, and (3) unbalance of routing path from registers to load circuits produces leakage. The implemented circuits were measured in terms of voltage fluctuation in the power distribution network for FPGA core circuit where the circuits were implemented. The measured voltage fluctuations were converted into internal current sources that were exploited to analyze the information leaking behavior by applying a side-channel analysis, correlation power analysis (CPA). The analysis confirmed that internal current source clearly demonstrated the side-channel information leaking behaviors. This results suggests that internal current source would allow to understand what parts of encryption circuits largely contribute to leak information and how to develop an efficient and low-cost countermeasure against side-channel attacks.

DOI： 10.1541/ieejfms.136.365

Scopus

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ディジタルICの電源供給回路網に付加するオンボードRLスナバの最適抵抗値決定式の導出

河田直樹, 吉野慎平, 矢野佑典, 五百旗頭健吾, 豊田啓孝

電気・情報関連学会中国支部連合大会講演論文集(CD-ROM) 67th 2016年

暗号回路におけるサイドチャネル情報漏洩挙動の内部電流源による分析

五百旗頭健吾, 田井伸拓, 籠谷裕人, 大西紘之, 豊田啓孝, 渡辺哲史

電気学会論文誌 A 136 ( 6 ) 2016年

近傍磁界分布測定を利用したサイドチャネル情報漏洩特性の分析

五百旗頭健吾, 矢野佑典, 豊田啓孝

電子情報通信学会大会講演論文集(CD-ROM) 2016 2016年

損失を有する共振器型フィルタ実用化のための複雑形状の電源/GND層間の共振抑制評価

久保輝真, 五百旗頭健吾, 豊田啓孝

電子情報通信学会大会講演論文集(CD-ROM) 2016 2016年

フェライト膜の電気的特性を考慮した損失を有する共振器型フィルタの設計 (環境電磁工学)

久保輝真, 豊田啓孝, 五百旗頭健吾

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 115 ( 309 ) 31 - 36 2015年11月

B-4-47 IC電源供給回路の共振抑制を目的としたオンボードRLスナバの最適パラメータ(B-4.環境電磁工学,一般セッション)

五百旗頭健吾, 河田直樹, 豊田啓孝

電子情報通信学会ソサイエティ大会講演論文集 2015 ( 1 ) 260 - 260 2015年8月

高密度実装のための差動線路屈曲部における非対称テーパ付密結合屈曲構造の収納性向上 (環境電磁工学) -- (若手研究者発表会)

王晨宇, 豊田啓孝, 五百旗頭健吾

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 115 ( 131 ) 49 - 54 2015年7月

Suppression of Mode Conversion by Using Tightly Coupled Asymmetrically Tapered Bend in Differential Lines

Yoshitaka Toyota, Shohei Kan, Kengo Iokibe

IEICE TRANSACTIONS ON COMMUNICATIONS E98B ( 7 ) 1188 - 1195 2015年7月

記述言語：英語出版者・発行元：IEICE-INST ELECTRONICS INFORMATION COMMUNICATIONS ENG

In this paper, we propose a tightly coupled asymmetrically tapered bend to suppress differential-to-common mode conversion caused by bend discontinuity in a pair of differential lines. Tightly coupled symmetrically tapered bends have been so far proposed to suppress the mode conversion by decreasing the path difference in the bend. This approach makes the path difference shorter so that the differential lines are coupled more tightly but the path difference of twice the sum of the line width and the line separation still remains. To suppress the remaining path difference, this paper introduces the use of asymmetric tapers. In addition, two-section tapers are applied to reduce differential-mode reflection increased by the tapers and hence improve differential-mode propagation. A full-wave simulation of a right-angled bend demonstrates that the forward differential-to-common mode conversion is decreased by almost 30 dB compared to the symmetrically tapered bend and that the differential-mode reflection coefficient is reduced to the same amount as that of the classic bend. Also, the generality of the proposed bend structure is discussed.

DOI： 10.1587/transcom.E98.B.1188

Web of Science

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Planar EBG Structure with Ferrite Thin Film for Power-bus Noise Reduction (Electromagnetic Compatibility)

TOYOTA Yoshitaka

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 115 ( 114 ) 29 - 32 2015年6月

電源系配線におけるモード変換位置へのコンデンサ実装によるコモンモードノイズ発生量の低減 (環境電磁工学)

三倉駿紀, 豊田啓孝, 五百旗頭健吾

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 115 ( 29 ) 7 - 12 2015年5月

アルカリ金属のスピン偏極を用いた低周波電磁波計測の検討 (環境電磁工学)

長岡孝幸, 田上周路, 豊田啓孝

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 115 ( 29 ) 43 - 48 2015年5月

B-4-63 差動線路の信号品質に与えるコモンモード特性インピーダンスの影響評価(B-4.環境電磁工学)

高力圭太, 菅翔平, 豊田啓孝, 五百旗頭健吾

電子情報通信学会総合大会講演論文集 2015 ( 1 ) 353 - 353 2015年2月

電源-グラウンド層間のノイズ低減のためのビアレス・オープンスタブ型EBG構造の提案 (環境電磁工学)

山下祐輝, 豊田啓孝, 五百旗頭健吾, 近藤幸一, 吉田栄吉, 金子俊之

電子情報通信学会技術研究報告 = IEICE technical report : 信学技報 114 ( 398 ) 57 - 62 2015年1月

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

周期構造による電磁バンドギャップ(Electromagnetic Bandgap: EBG)形成(EBG構造)により,プリント回路基板の電源-グラウンド層間の高周波ノイズを低減する検討が行われている.EBG構造はその抑制量が非常に大きいため,デジアナ混載基板において微弱な信号を扱う高周波回路部に対してディジタル回路部で発生する同時スイッチングノイズの伝搬抑制に有効である.EBG構造には様々な形状があるが,大まかにはビアの有無で分類できる.我々は,ビアの無いプレーナ型EBG構造に着目して高周波ノイズの抑制を検討してきた.これは2層で構成でき,ビアが不要であることからコスト面からも有利と考えられるためである.一方,ビア有りのEBGで提案されているオープンスタブEBGは抑制周波数に依存せず小型化が可能である.オープンスタブEBG構造はビア有りに特有の構造と考えていたが,本報告では,構造を工夫することでビア無しのプレーナ型オープンスタブEBG構造を提案する.そして,電磁界シミュレーションによりその抑制効果を調べ,2.4GHz帯においてそれを確認した.

CiNii Article

CiNii Books

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Effect of Mg loading on the high-frequency tunability of Ba0.8Sr0.2TiO3 ceramics

Takashi Teranishi, Tsuyoshi Sogabe, Hidetaka Hayashi, Akira Kishimoto, Kengo Iokibe, Yoshitaka Toyota

JAPANESE JOURNAL OF APPLIED PHYSICS 54 ( 1 ) 11502-1-011502-6 2015年1月

記述言語：英語出版者・発行元：IOP PUBLISHING LTD

The effect of Mg loading on the high-frequency tunable properties and dielectric loss of Ba0.8Sr0.2Ti1-xMgxO3 (BSTM) ceramics was investigated. Variation in the lattice parameters and the 90 degrees domain configuration with Mg loading indicated a decrease in the tetragonal distortion. Additionally, the 90 degrees domain size decreased slightly with a low Mg loading, up to 0.1 mol %, resulting in a higher domain-wall density compared with the non-doped specimen. The 0.075 mol% Mg-loaded BSTM ceramic exhibited the highest tunability; this was attributed to the domain-size effect. The loss tangent (tan delta) roughly decreased with Mg loading, due to loaded oxygen vacancies. The maximum figure of merit value (FOM = tunability/tan delta) at 10 MHz was achieved for the 0.075 mol% Mg specimen, twice that of the non-doped specimen, due to an increase in the tunability and a decrease in the loss tangent with Mg loading. (C) 2015 The Japan Society of Applied Physics

DOI： 10.7567/JJAP.54.011502

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Dependence of Power Distribution Network Impedance on Circuits Implemented in Field Programmable Gate Array

Nobuhiro Tai, Kengo Iokibe, Yoshitaka Toyota, Tetsushi Watanabe, trial Technology Center of Okayama Pre

Eighth 2015 Korea-Japan Joint Conference on EMT/EMC/BE (KJJC-2015), P-09, Sendai, Japan 85 - 86 2015年

線路接続部で生じるモード変換の等価回路モデル－モデルの妥当性とノイズ抑制に向けた検討－

豊田啓孝

電磁環境工学情報EMC 321 ( 9 ) 85 - 100 2015年

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