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）

The transmission line constructed with cable and ground plane is one of the radiated emission sources. Therefore, the characteristics of the line should be investigated to achieve electromagnetic compatibility. The numerical analysis has the merit that the characteristics can be investigated effectively, but the perfect modeling of this transmission line is difficult. In this paper, we evaluated the calculation accuracy from 0.1 MHz to 1000 MHz by comparing the calculating line constants with the measuring values. As a result, it was found that the characteristic impedance and phase constant can be calculated with a certain degree of accuracy, but the deviation of the attenuation constant is large.

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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）

In this report, the mechanism of mode conversion of interfering electromagnetic waves injected into communication equipment from coaxial cables to in-vehicle communication modules is evaluated and clarified from the viewpoint of immunity. A mode conversion equivalent circuit was used for this purpose. Considering radiated immunity, the applied electromagnetic field induces a common-mode current in the coaxial cable, which propagates through the cable to the signal line inside the enclosure via a connector. When microstrip lines are used within a printed circuit board, the imbalance difference between the two transmission lines causes a conversion from common-mode current to normal-mode voltage. Furthermore, when the imbalance difference is small, the parasitic inductance between the ground connections at the connectors is dominant in the mode conversion. To evaluate these phenomena, a mode transformation circuit with ideal transformers was created. The circuit simulations were conducted using the model and a modal transmission line. The obtained results showed the same trend as that of the 3D electromagnetic field simulation.

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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）

The impedance balance method is used as a countermeasure against electromagnetic noise in power electronic circuits. In a previous research, the authors' research group confirmed the reduction of common-mode voltage in a three-phase inverter circuit using the impedance balance method. However, it has been difficult to reduce common-mode voltage using conventional methods in an electric compressor system with an integrated mechanical and electrical structure, where the three-phase inverter and motor are housed in a single housing. This research describes a method to reduce the common-mode voltage in an electric compressor system with an integrated mechanical and electrical structure, using an impedance balance method. The first is to reduce the impedance of the balancing elements added to the circuit, and the second is to increase the impedance of the three three-phase output line connecting the three-phase inverter and the motor. By combining these two methods, the frequency bandwidth of the reduction effect was expanded from 2 MHz to 30 MHz, and a reduction in common-mode voltage of up to 30 dB was confirmed.

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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）

As the marine business expands, there is a growing demand for real-time capturing of autonomous underwater vehicles (AUVs) status using radio frequency communications. On the other hand, electromagnetic noise emitted by AUVs can interfere with communications. To investigate the impact of electromagnetic noise in undersea Wavelet-OFDM communication, the author constructed an experimental setup that simulates the radio wave transmission characteristics of underwater antennas without the experimental environment in the sea and introduced external noise to assess communication speed. The authors compared the noise power induced in the receiver to the communication speed using the proposed evaluation setup. The results shows that when the distance between the loop antennas was 1 m, communication was disabled by applying a -90 dBm disturbance. Additionally, the author proposed a method to estimate communication speed using transmission characteristics and measured electromagnetic noise. The communication speeds calculated using the proposed method agreed with the measured results with a maximum error of 1.65 Mbps. Improving accuracy remains a challenge for future research.

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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）

In this paper, we compared the immunity characteristics of wiring harnesses connecting automotive communication equipment at different wiring lengths. The communication behavior of an automotive harness connected to an evaluation module equipped with automotive Ethernet and exposed to radiated electromagnetic noise was compared for different wiring lengths. The S-parameters were measured under the same wiring conditions, and the frequency characteristics of the amount of noise applied were derived and compared with the length of the wiring. A reverberation chamber was used for the evaluation. From the results of each evaluation, changes in immunity characteristics due to differences in wiring length were confirmed for each frequency of electromagnetic waves, but no correlation was observed between communication quality characteristics and the results of S-parameter measurement. On the other hand, the frequency characteristics of the amount of noise applied also changed with the difference in wiring length, suggesting that a stable evaluation is possible with longer wiring lengths.

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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）

The authors' research group is engaged in research and development of undersea radio communication technology. To improve communication efficiency, antenna characteristic and communication system are being developed through actual measurement. However, it is not easy to conduct large-scale measurement because of the time and cost required for preparation. Therefore, an undersea communication emulator that simulates undersea radio wave attenuation is being built to simplify large-scale experiment. In this paper, an undersea communication emulator of the transmission characteristic obtained by actual measurement is fabricated, and comparison of transmission characteristic and communication performance are shown through communication experiment. As a result of evaluating the communication characteristics of the fabricated emulator, it was confirmed that the transmission characteristic was expressed with a difference of less than 1 dB in a bandwidth of approximately 85 % of the carrier frequency, and that the transmission rate could be simulated with an accuracy of less than 1 Mbps.

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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）

The Autonomous Underwater Vehicle (AUV) is anticipated as a means of collecting underwater visual information using its built-in camera. While underwater radio wave communication via underwater antennas has been developed as a means of information collection, it is expected that the metal casing of AUV may adversely affect the transmission characteristics of antennas in underwater radio wave communication. Therefore, this report evaluates the impact of AUV's metal casing on antenna-to-antenna communication using an electromagnetic field simulator. The evaluation indicates that when the size of the antennas is larger than the AUV's metal casing, the impact on transmission characteristics is minimal even when the AUV is positioned between the antennas. On the other hand, when the metal casing is larger than the antenna size, the transmission characteristics between antennas degrade due to eddy currents flowing in the metal casing induced by antenna currents. Consequently, it is suggested that when attaching underwater antennas to AUVs, maintaining relatively good transmission characteristics, even with smaller antennas, is possible by appropriately configuring the size relationship and placement of the metal casing relative to the antennas.

Scopus

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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）

A matching circuit is required to improve the transmission characteristics of an antenna for undersea radio communication. Even if the reflection coefficient, S11, the transmission characteristics will not necessarily improve in a system with high radio-wave attenuation in the sea. Therefore, the authors designed a matching circuit to maximize transmission efficiency in the frequency band used. However, it is necessary to acquire the transmission characteristics between the antennas through experiment or simulation for circuit design. In the proposed circuit, an N-section LC ladder circuit is used. When the proposed matching circuits are connected to the antenna, the transmission coefficient is improved up to 12 dB.

DOI： 10.23919/ICEP61562.2024.10535535

Scopus

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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）

Kyushu Institute of Technology (Kyutech) is developing a 6U CubeSat that is named 'VERTECS' (Visible Extragalactic background RadiaTion Exploration by CubeSat). This is an astronomical CubeSat designed to reveal star formation history by observing visible extragalactic background light [1] and the first satellite for Kyutech to rely on not UHF (around 400 MHz) but only microwave (>1 GHz) to communicate between the satellite and ground station. Microstrip patch antennas are adopted on this CubeSat due to desired characteristics such as low profile, lightweight, and non-deployable structure. However due to the performance of the microstrip patch antenna is limited such as directional radiation pattern and narrow operational bandwidth, the placement of the antenna on CubeSat is more critical compared to that of the conventional antenna for UHF communication, such as dipole and monopole antenna. In this paper, we describe choosing the antenna placement while considering antenna performance, including the coupling of transmission and reception antenna.

DOI： 10.23919/ICEP61562.2024.10535673

Scopus

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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）

The design and fabrication of a miniaturized, circularly polarized Microstrip Patch Antenna (MPA) for wireless and small satellite applications at S-band is reported in this paper. The Defected Ground Structure (DGS) technique is applied in a normal circular polarization MPA to create a degree of miniaturization. The results showed that the miniaturized antenna has an operation frequency of around 2.47 GHz while having the same size as the original antenna working at 3.1 GHz, it means that it is a miniaturization efficiency of 21% has been reached. The measured gain is about 1 dBi at 2.47 GHz. Additionally, the AR is below 3 dB at this operation frequency, it indicates that the quality of circular polarization has been maintained. This antenna design is promising when applied in compact wireless devices, as well as small satellites applications.

DOI： 10.1109/iWAT57102.2024.10535821

Scopus

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記述言語：英語   掲載種別：記事・総説・解説・論説等（その他）

DOI： 10.1109/MEMC.2024.10711976

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担当区分：責任著者   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）

With angle of incidence, The authors evaluated how the variation of transmission attenuation to glass for radio waves in the 28 GHz band used in 5G communication. As a result, we observed that the transmission attenuation tends to decrease as the angle of incidence increases for horizontal magnetic field polarization to the glass. In contrast, for horizontal electric field polarization to the glass, the transmission attenuation tends to increase as the angle of incidence increases. Additionally, we observed the variation of transmission attenuation with angle of incidence was different, even for samples with close transmission attenuation at the frontal angle. A variation of approximately 1.7 dB in transmission attenuation was observed within the range of 0 to 45 degrees for both horizontal magnetic field polarization and horizontal electric field polarization, in all samples except for Low-E Glass. Furthermore, the range of variation in transmission attenuation with angle of incidence was shown to be broad, comparable to the minimum transmission attenuation observed for each sample. In the case of Low-E Glass, approximately 8 dB variation was observed within measured range. These results highlight the importance of considering more detailed sample characteristics and varying angle of incidence when evaluating and designing radio wave propagation paths.

DOI： 10.1109/APMC57107.2023.10439778

Scopus

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Autonomous Underwater Vehicles (AUVs) require long-distance communication, especially in the deep sea. Acoustics communication and wireless optical communication have limitations of low latency and water conditions effects respectively. Radiofrequency (RF) communication provides a high data rate with free orientation of the transmitter/receiver antennas. However, electromagnetic waves are highly restricted by high attenuation over short distances in the underwater medium. In this study, we investigated the RF communication in a tank full of seawater. A loop antenna and rectangular antenna were used for the base station and AUV respectively. The experiments were conducted to measure the transmission rate with different distances between the base station and the AUV using both User Datagram Protocol (UDP) and Transmission Control Protocol (TCP). Live video streaming with framerate analysis was considered. The results show the effect of the distance between the transmitter and receiver on the transmission rate, in addition, to the antenna's stability has huge effects on the connection stability. We successfully achieved a High-Definition (HD) video streaming with 25fps for over 1 meter.

DOI： 10.57417/jrnal.10.1_84

Scopus

CiNii Research

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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）

Autonomous Underwater Vehicles (AUVs) require long-distance communication, especially in the deep sea. Radiofrequency (RF) communication provides a high data rate. However, electromagnetic wave is seriously limited by high attenuation in the water medium. In this study, we investigate Radiofrequency communication in seawater. The experiment results show the effects of the distance between the transmitter and receiver, and the stability of the antennas. We achieved HD video transmission with 25fps.

Scopus

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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）

The impedance-balancing method is a way of reducing common-mode voltage. However, when it is applied to a three-phase inverter circuit, the inductances of the two conductor lines supplying the power affect the common-mode voltage. Here, we investigated the effect of the inductance of the conductor lines supplying power on the common-mode voltage in the impedance balancing method by using a circuit simulation. The results show that when the balance of the inductances of the two conductor lines changes, the value of the balancing element that reduces the common-mode voltage also changes. An analysis of the common-mode voltage during individual switching of the insulated-gate bipolar transistors constituting the three-phase inverter shows that it is reduced under all switching conditions.

DOI： 10.1109/EMCEurope57790.2023.10274203

Scopus

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担当区分：責任著者   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）

It is known that power line communication (PLC) works across different phases in a three-wire three-phase distribution system; even through the pairs of lines for each phase are not physically connected. This research focuses on the distribution boards in the power distribution network and evaluates the effect on PLC of an earth leakage circuit breaker(ELCB) attached to the boards. The results of an evaluation of the common-mode current with and without the ELCB showed that it increased with the ELCB. Resonance in our setup occured at 20 MHz. A simulation analysis showed that the capacitor connecting the two wires at both ends of the ELCB contributed to the resonance.

DOI： 10.1109/EMCEurope57790.2023.10274371

Scopus

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）

今日，IoT化の需要増に伴い，工場等の大規模施設での高速電力線通信(PLC)の要望が高まっている．これまで，一般家庭における単相電力線における伝送特性等の研究は多く行われてきたが，大規模施設における分電盤を経由するPLC信号の透過特性に分岐数やブレーカーの構造が与える影響，及び異相間通信を含む透過特性は明らかにされていない．そこで，本論文では，工場等の大規模施設で利用される分電盤を経由する透過特性について，まずブレーカー単体における信号伝搬特性を検討し，漏電ブレーカーのキャパシタの影響により通常ブレーカーに比べてミクスドモードSパラメータ値が大きくなることを示した．そして，分電盤を経由する通信において分岐数がどのように影響するかを測定と解析により検討し，いずれの場合でもおおよそ分岐数分の1に近くなることを示した．本論文により分電盤を経由した透過特性を概算することで，PLCの中継器を設置すべき場所を推定することが可能となる．

DOI： 10.14923/transcomj.2022pep0001

CiNii Research

担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（学術雑誌）

差動信号のインタフェースは多くの車載機器に使用されており，コモンモードフィルタ（CMF: Common Mode Filter）がキーデバイスとして使用される．CMFの特性指標としてミクスドモード・Sパラメータが使用され，デファレンシャルモード(DM)である信号がCMFの不均衡によりコモンモード(CM)に変換され放射エミッションに大きく寄与する．ミクスドモード・Sパラメータはそれぞれに位相特性が含まれており，元々発生するCM信号の位相とモード変換によって生じたCM信号の位相は同じではなく，単純に比較できない．そのためCMFの選択においても従来システムとして組み込んでCISPR25に準拠した形で比較評価を行う必要がある．本研究においては，CMFの有用性を確認する方法の一つとして等価コモンモード電圧 VEQ の計算式を求め，あるDM信号源とCM信号源の矩形波に対してそれぞれのCMFの VEQ を算出した．次に，信号源の条件が同じ波形を用いて36 MHzから196 MHzまでの放射エミッションレベルをCISPR25に準拠した測定により評価した．その結果，等価コモンモード電圧 VEQ と大小関係が同じ傾向だったことがわかった．

DOI： 10.14923/transcomj.2022pep0009

CiNii Research

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）

Common-mode filter (CMF) is a vital device to improve electromagnetic compatibility (EMC), and the analysis of the CMF effect is essential to improve the design quality of EMC. This paper analyzes the suppression effect of CMF used for telecommunication lines using a chain parameter matrix. The chain parameter matrix represented the CMF and the interface cable, and the S21 at the far end of the cable was calculated. The analytical method was validated by comparing measurements using unshielded twisted pair (UTP) and shielded twisted pair (STP) cables. The results showed that the analysis method was appropriate for analyzing the suppression effect. Using the analysis method, the suppression effect was evaluated by the common mode (CM) current at the cable input and the radiated electric field. The result showed that the characteristic impedance and the transmission loss of the CM transmission line affect the suppression effect. The result also showed that the suppression effect by the radiated electric field could be estimated from the suppression effect by the CM current at the cable input.

DOI： 10.1109/EMCSIPI50001.2023.10241556

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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）

AUVs are used for marine resource exploration, and although acoustic, laser, etc., are often used for wireless communication for AUVs, wireless communication using RF signals is being studied. By placing the VNA in a waterproof container, we measured the insertion loss between the antennas under seawater and obtained good results with simulation results. Furthermore, using a Wavelet-OFDM module as the communication method, a maximum communication speed of 6.8 Mbps was achieved with the antennas embedded in the AUV immersed in seawater.

DOI： 10.23919/EuCAP57121.2023.10133725

Scopus

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記述言語：日本語   掲載種別：研究論文（学術雑誌）

DOI： 10.11486/ejisso.37.0_14a5-4

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）

When designing on-chip power distribution networks (PDNs) of a large-scale integrated circuit (LSI), power integrity (PI) must be ensured not to cause malfunctions. LSI-core macromodels are expected to be used for fast PI simulation. When building LSI-core macromodels from design information, the impedance and equivalent current sources are often extracted for each function block or smaller operating block. In the stage of modeling function blocks, the layout and operation of the surrounding function blocks are not fixed, so equivalent current sources of the macromodel of each function block are extracted under ideal power supply conditions. However, in an actual LSI, the on-chip PDNs have a certain impedance and the power supply voltage of each function block is not ideal dc voltage because of its own operation and the interference from the operation of surrounding function blocks in the same power domain. Since operating currents of transistors are affected by on-chip supply voltage fluctuations, this effect must be taken into account when simulating the PI of the entire LSI or the simulation accuracy will degrade. This article proposes a PI simulation method using LSI-core macromodels that takes into account on-chip supply voltage fluctuations due to the interference between function blocks in the same power domain. To verify the proposed method, a test chip with several function blocks was built, and it was confirmed that the proposed method can simulate PI with high accuracy.

DOI： 10.1109/TEMC.2022.3224704

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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）

Since seawater has high attenuation of electromagnetic waves, the transmitting and receiving antennas are magnetically coupled using a coil with a diameter of 80 cm. The antenna is submerged in saltwater, and insertion loss is measured using a VNA. The communication speeds experiment of the UDP and TCP protocols is conducted when the distance between the transmitter and receiver antenna is changed.

Scopus

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担当区分：責任著者   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）

EMI testing of in-vehicle equipment must be conducted during the automotive development phase. ICs used in automotive equipment need to be replaced by ICs with stable supply due to the shortage of semiconductors. However, it is inefficient to perform EMI testing for every change. Therefore, we are researching a mechanism to complete the evaluation of radiated noise generated from wire harnesses connected to in-vehicle electronic devices with a single IC. We examined and compared the results of two EMI testing methods. One is radiated emission measurement from a wire harness with equipment, while the other is the conducted emission measurement of an IC. The radiated emissions from the wiring harnesses connected to the vehicle-mounted equipment were measured in accordance with CISPR 25 (ALSE). On the other hand, the measurement of conducted emissions from a stand-alone vehicle-mounted IC complies with IEC 61967-4. As a result, it was confirmed that ICs that performed lower noise in stand-alone IC measurements also performed lower noise in mounted in-vehicle equipment. The results show that there is a relationship between the radiated noise from the wiring harness and the conducted noise generated by the individual vehicle-mounted ICs.

DOI： 10.1109/ICSJ55786.2022.10034693

Scopus

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担当区分：筆頭著者   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）

This paper investigates common mode generation in a wideband communication system using magnetic field coupling with two coils. Two coils are placed in parallel and communicate without resonance in the frequency band below 100 MHz. In this case, the common mode current to the feeder line may cause the transmission of electromagnetic field beyond the designed communication range. The circuit analysis shows that both magnetic and electric field coupling contribute to the common mode generation. It was also suggested that the phase difference between these couplings may cancel the common mode generation.

DOI： 10.1109/APEMC53576.2022.9888658

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担当区分：最終著者   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）

RF interference is a vital issue to construct the communication network using many Internet of Things (IoT) devices. This study proposes the rapid estimation three-dimensional communication range for the wireless communication system using magnetic field coupling of air-core coils in HF broadband communication. Firstly, an equivalent circuit for rapid calculation of transmission coefficient between transmission coils is shown. The theoretical equation for accurate calculation of the inductance of a straight conductor is derived, followed by the calculation of the total inductance of coils by combining inductances of straight conductors. Then, the calculation speed and accuracy of the proposed method are verified by the simulation and the measurement using the coil implemented on a printed circuit board (PCB). As a result, the proposed method can calculate the transmission coefficient in a few milliseconds, and the error is approximately 1 dB compared to the measurement results. Additionally, it plotted the entire communication range in 3 seconds for the case study of a 2-turns coil.

DOI： 10.1109/EMCSI39492.2022.9889342

Scopus

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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）

Common-mode choke coil (CMC) is used in vehicles and electronic devices to improve electromagnetic compatibility (EMC), and the analysis of the CMC effect is essential to improve the design quality of EMC. In this paper, the suppression effect of CMC for the common-mode (CM) signal converted from the differential-mode (DM) signal is analyzed using a chain-parameter matrix. The chain-parameter matrix of the CMC was obtained from the SPICE model and the measured data. And then, the amount of conversion level from DM signal to CM signal was calculated using the chain-parameter matrix of the signal source, the termination, the cable, and the CMC. The CM signal level was calculated for the shielded twisted pair cable with one pair considering imbalances of the signal source, the termination, the cable, and the CMC. The calculation value was compared to the measurement value due to confirm the validity of the method, and the calculated results were in close agreement with the measurement value. The investigation results showed that we should pay attention to the CMC imbalance when the cable is well balanced. In addition, the results suggested that the CMC should be prepared at both ends of the cable to reduce the current outside the shield.

DOI： 10.1109/EMCSI39492.2022.9889495

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担当区分：責任著者   記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

DOI： 10.5104/jiep.25.309

Scopus

CiNii Research

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記述言語：日本語   掲載種別：研究論文（学術雑誌）

DOI： 10.11486/ejisso.36.0_24b5-1

CiNii Research

記述言語：日本語   掲載種別：研究論文（学術雑誌）

<p>The authors propose an effective method of fault location utilizing TDR measurement in overhead distribution systems. Past studies have shown that reflected waves from accident points such as short circuits, ground faults, and disconnections can be observed in overhead distribution systems. In addition, it is known that the retaining insulators and pulling insulators of overhead power distribution line cause reflected wave because these equipment act as capacitor. On the other hand, although there are many other distribution facilities, the reflection characteristics cannot be evaluated quantitatively. Based on the above, the purpose of this study is to create an equivalent circuit model for TDR measurement for various distribution facilities existing in the overhead distribution system. For modeling, an equivalent circuit model is created by the power system instantaneous value analysis program XTAP, and the experimental results and simulation results are compared and evaluated.</p>

DOI： 10.1541/ieejpes.142.139

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その他リンク： https://www.jstage.jst.go.jp/article/ieejpes/142/2/142_139/_pdf

記述言語：英語   掲載種別：研究論文（学術雑誌）

The use of PLC (power line communication) is growing as the adoption of IoT technology becomes more widespread. However, the maximum communication distance between PLC modems cannot yet be clearly defined since the communication characteristics of the power lines used for PLC are not formally specified. In this paper, the propagation characteristics in the high-speed PLC communication band of 2–30 MHz were investigated when equipment is not connected to the power line except both ends. The line constants for five typical types of cables used as single-phase and two-wire power lines were measured. Our results showed that different cables have markedly different transmission characteristics. The attenuation constant varied up to fourfold depending on the cable insulator material. We also derived a method of estimating the communication distance for different cables for application of the HD-PLC system, which is the most commonly used type of high-speed PLC. The measurement result by using VCT cable was almost agreed with the estimated value. By comparing the estimated distance with the experimental results, we show that the transmission distance can be estimated with sufficient accuracy for practical use. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

DOI： 10.1002/tee.23535

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担当区分：責任著者   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）

In a conventional TLP system, the pulse disturbance is applied to the DUT via the transmission line, whose characteristic impedance is 50 Ω. However, the DUT for the evaluation, such as an ESD protection device, may be affected by the transmission line’s characteristic impedance. This paper adds an impedance matching circuit to the conventional 50 Ω TLP system, making it possible to adjust the circuit to an arbitrary value of the transmission line’s characteristic impedance. By using the developed system, the IV characteristics of an ESD protection device are evaluated when the characteristic impedance is 20 Ω, 50 Ω, and 150 Ω. As a result, it was found that the negative resistance characteristics after the breakdown voltage change depending on the transmission line’s characteristic impedance.

DOI： 10.1109/ICSJ52620.2021.9648864

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Because radiation is essential in high-frequency circuits, such as those used in metamaterials and plasmonics, the investigation of radiation loss is important. This study describes the characteristics of radiation loss, which is a radiation reaction in circuits with retarded electromagnetic couplings. The structure of wired metallic spheres is used to demonstrate metamaterial equivalent circuits, where charges and current exist on the spheres and wires, respectively. An inductance matrix and a potential coefficient matrix with retarded electromagnetic couplings are defined to address the radiation reaction. Subsequently, based on the topology of the wires and spheres, an equivalent circuit equation with retardation is formulated to discuss the losses in the resonant circuit caused by the inductive and capacitive elements. Thereafter, the relationship between the resonant frequency and radiation loss caused by the retarded couplings is demonstrated and the difference between the retarded couplings and couplings with transmission lines is clarified. Furthermore, we indicate that retarded coupling generates singularity on a dispersion curve for a one-dimensional array of resonant circuits. Thus, the circuit with retarded couplings generates novel characteristics of radiation reactions that are not represented by the circuit without retardation. This circuit analysis is expected to afford new aspects in studies on topics, such as metamaterials and plasmonics.

DOI： 10.1049/cds2.12104

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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）

Currently, as a method of identifying fault location on a distribution line, Time Domain Reflectometry (TDR) measurement has been studied. In this study, the fault part is identified by injecting a pulse wave into the distribution line, measuring the reflected wave at the fault point, and comparing the difference between the waveforms before and after the fault. A Previous studies have shown that TDR measurements can be applied to overhead distribution system[1,2]. This paper reports that the fault location by TDR measurement using pulse waves is effective for the underground distribution system as well as the overhead distribution system, with verification on an actual line including multiple ground-mounted equipment.

DOI： 10.1049/icp.2021.2100

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記述言語：英語   掲載種別：研究論文（学術雑誌）

The authors propose an effective method of fault location in overhead distribution system. In past studies, short pulse with high frequency injected into overhead distribution system can propagate through about 1 km distance, but it has been a problem that pulse reflect at other than a fault point. In other words, it is necessary to find out a fault point from multiple reflected waves. In our proposed method, it is possible to extract a change of a fault point by comparing TDR (Time Domain Reflectometry) waveforms before and after failure. In this paper, we clarify theoretical concept and organize the algorithm of comparing TDR waveforms. Moreover we verify effectiveness of the proposed method by experiments in real-scale distribution system after confirming pulse transmission properties of section switch. The verification results show that the proposed method can locate a fault point (short-circuit fault or ground fault) with accuracy of tens of meters or less.

DOI： 10.1541/ieejpes.141.590

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記述言語：英語   掲載種別：研究論文（学術雑誌）

CCBY Increasing attention has been paid to the study of electromagnetic (EM) phenomena in complicated wire networks [e.g., metamaterials and EM compatibility (EMC)]. However, their lack of physical insights usually prevents systematic analysis of the phenomena. To address this, this article describes a transmission line (TL) model of a finite-length single conductor without a return current path to be applied as a fundamental physical model. The model includes radiation effects in a self-consistent way (i.e., its radiation reaction is included in an explicit way), and it is based on Sommerfeld principal wave propagation (strictly speaking, its behavior is asymptotic as the wire&#x2019;s conductivity approaches infinity). This formulation naturally leads to the consequence that the current flowing along a single conductor illuminated by an incident EM field is classified into three components, which are dominated by physically distinct principles, the principal wave itself (<formula><tex>$I_{\rm tr}$</tex></formula>, the traveling wave), the one reinduced by the traveling wave radiation (<formula><tex>$I_{\rm re}$</tex></formula>, the radiation reaction), and the one that directly scatters the incident field (<formula><tex>$I_{\rm sc}$</tex></formula>, the scattering wave). The EM energies of the traveling wave and radiation reaction components are stored in the TL and propagate, while the scattering component indicates an instantaneous scattering process. These components reveal the dynamical characteristics of a single-conductor TL model that includes radiation phenomena.

DOI： 10.1109/TEMC.2020.3041468

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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）

Radiated emission from shielded twisted pair (STP) cable was calculated using a chain-parameter-matrix. The series connection of the matrix represented the transmission line inside the shield, and the common-mode (CM) current was obtained by solving the matrix equation. The induction voltage on the outside of the shield was determined from the CM current using the shield's transfer impedance. The current on the outside of the shield was calculated from this induction voltage. And then, the radiated electric field was calculated from this current. The matrix elements representing the transmission line between conductors and shield were determined from the measurement, and the transfer impedance was also determined from the measurement. The line constants between shield and ground were determined from the theory by assuming the shield as a copper rod. The maximum current on the outside of the shield and the maximum radiated electric field were measured in the frequency range from 30 MHz to 300 MHz, and these were compared to the calculated value. The calculation results of the maximum current intensity were well agreed with the measured value, and the calculation results of the maximum radiated electric-field strength were almost agreed with the measured value.

DOI： 10.1109/EMC/SI/PI/EMCEurope52599.2021.9559295

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担当区分：筆頭著者   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）

A mode division multiplex transmission system that assigns signals to the eigenmodes of a transmission line was proposed for a cable that is uniform in the longitudinal direction. The transmission characteristics when the proposed method is used in a 1m long shielded untwisted 4-wire cable were verified by circuit simulation. It is shown that the proposed method enables four-channel simultaneous transmission. In addition, the proposed method significantly improves the crosstalk compared to the differential and single-ended transmission methods.

DOI： 10.1109/EMC/SI/PI/EMCEurope52599.2021.9559178

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記述言語：日本語   掲載種別：研究論文（学術雑誌）

LVDS (Low Voltage Differential Signaling)ドライバが電流差動駆動系であることに着目し，完全平衡ではない伝送系をLVDSドライバで駆動した際に発生するコモンモードを低減する手法を提案する．抵抗による簡単な平衡度補正回路の追加により不平衡系のコモンモードを低減する．シミュレーションと実験により，不平衡度が0.5から大きくずれた系においても，大幅にコモンモード発生量を低減することが可能であることを示す．LVDSドライバと平衡度補正を用いた準差動伝送系について，実験によりコモンモード電位変動の低減を確認した．

DOI： 10.14923/transcomj.2020pep0007

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）

In this paper, the influence to electromagnetic environment was evaluated on the outside of buildings where power line communication (PLC) systems were installed to a three-wire three-phase power distribution line. The electric field strength was measured at 140 points in five factories, in two office buildings, and in one stadium. Since many radio waves existed in the environment, the electric field strength when PLC system was operated and was not operated was measured. The influence was evaluated by the cumulated occurrence probability because the frequency characteristics of the electric filed strength changed by the measurement points. The results showed that the occurrence probability was not changed when the PLC system was operated and was not operated. The electric field strength was calculated by the common mode current obtained from the test result, and this indicated that the occurrence probability was lower than the measured occurrence probability of electric field strength.

DOI： 10.1002/eej.23324

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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）

A common-mode choke coil (CMC) is an essential device for achieving electromagnetic compatibility (EMC). An equivalent circuit considering the common-mode (CM) disturbance converted from differential-mode (DM) signal is needed because the spectrum of telecommunication signals overlaps with the regulated frequency band of the radiated disturbance due to the increase of telecommunication speed in recent years. In this paper, an equivalent circuit of CMC considering the conversion phenomenon is proposed. The admittances were inserted between each terminal of the CMC and the ground for demonstrating the phenomenon. The SPICE model of CMC was represented by the combination of the ABCD chain-parameter-matrices, and the elements of the overall matrix were calculated. The mixed-mode S-parameters were calculated using these elements. The elements of the ABCD matrix and the mixed-mode S-parameters were measured and the admittance values were determined by comparing the calculated data with the measured data. The pulse response calculated by the proposed equivalent circuit was well agreed with the measurement value.

DOI： 10.1109/EMCCompo52133.2022.9758620

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記述言語：英語   掲載種別：研究論文（学術雑誌）

CiNii Article

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記述言語：英語   掲載種別：研究論文（学術雑誌）

<p>Adverse effect of pulse disturbances on the communication quality is investigated experimentally on in-vehicle Ethernet (1000BASE-T1, IEEE 802.3bp). Common- and differential-mode pulse disturbances were injected into communication cables by a method referring to the coupling network described in IEC 62228-5. As a result, it was revealed that steep change of differential signal due to pulse disturbance degrades the communication quality at a specific pulse width.</p>

DOI： 10.1587/comex.2020COL0019

CiNii Article

CiNii Research

その他リンク： https://ci.nii.ac.jp/naid/130007871606

記述言語：日本語   掲載種別：研究論文（学術雑誌）

© 2020 The Institute of Electrical Engineers of Japan. In this paper, the influence to electromagnetic environment was evaluated on the outside of buildings where power line communication (PLC) systems were installed to a three-wire three-phase power distribution line. The electric field strength was measured at 140 points in five factories, in two office buildings, and in one stadium. Since many radio waves existed in the environment, the electric field strength when PLC system was operated and was not operated was measured. The influence was evaluated by the cumulated occurrence probability because the frequency characteristics of the electric filed strength changed by the measurement points. The results showed that the occurrence probability was not changed when the PLC system was operated and was not operated. The electric field strength was calculated by the common mode current obtained from the test result, and this indicated that the occurrence probability was lower than the measured occurrence probability of electric field strength.

DOI： 10.1541/ieejfms.140.557

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CiNii Research

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担当区分：責任著者   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）

担当区分：責任著者   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）

担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

© 1964-2012 IEEE. In wired signal transmission, conversion between the differential and common modes deteriorates the quality of the transmitted signal and also causes electromagnetic compatibility problems in the environment. Therefore, the transmission-line components are requested to be tested on their conversion loss characteristics, such as the longitudinal conversion loss (LCL), transverse conversion loss (TCL), and mixed-mode S-parameters. Theoretical investigations are carried out to analyze the mode conversion of a differential one-port device in order to express the conversion loss parameters in terms of the modal impedances of the device. Consequently, the mutual relationships among the parameters are derived using the modal impedances. In addition, a new LCL measurement method is proposed that can accurately determine LCL values of a device under test by using a vector network analyzer instead of a traditional balun-transformer measuring instrument. Furthermore, it is found that the ratio of the TCL to LCL is not constant but varies with device characteristics. Therefore, a new definition of the TCL is proposed in place of the conventional one. The validity of these theoretical results is confirmed through SPICE simulation and measurements.

DOI： 10.1109/TEMC.2019.2958935

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担当区分：責任著者   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）

© 2020 IEEE. Power line communication (PLC) is the technology that uses a power line as a signal line. Because an imbalance of the power line is generally larger than that of the communication line, we should take care of radiated emission from the PLC cable. A small-scale model can be applied to evaluate easily the radiated emission from PLC cables for large structures. In a scale model, all structures in the PLC system need to be manufactured as 1/n size to satisfy complete equivalence between the reference model and its scale model, though it is difficult to fabricate the fine structure such as conductors in a cable smaller. Therefore we investigated the effect on common-mode current when some parameters of the scale model were not scaled down perfectly. As a result, a reliable scale model was obtained to evaluate peak common-mode currents in resonant frequency even if some parameters of the structure were incompletely scaled. Furthermore, the cable length dependency of common-mode current was evaluated experimentally by using the scale model.

DOI： 10.1109/EMCEUROPE48519.2020.9245868

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担当区分：筆頭著者   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）

© 2020 IEEE. In this paper, reduction effect of a common-mode filter is discussed. When the performance of a common-mode filter is evaluated, it is necessary to consider not only SCC21 but also SCD21. Using these two parameters, the common-mode current flowing on the secondary side of the common-mode filter was formulated. Common-mode current is a summation of two causes: common-mode transmission and differential mode conversion from a signal source. The common-mode current depends on not only the phase relationship between SCC21 and SCD21 of the common-mode filter but also the phase relationship between the differential mode and the common mode of the signal source. Even if the same common-mode filter is used on a differential signaling system, the common-mode current increases or decreases depending on the phase of the differential mode voltage and the common-mode voltage at the signal source.

DOI： 10.1109/EMCEUROPE48519.2020.9245809

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担当区分：筆頭著者   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）

© 2020 IEEE. The radiated emission of the power line communication (PLC) system should be investigated to maintain electromagnetic compatibility. Recently, the development of applying the PLC system to factories and offices was started. In these environments, many cables are arranged in the cable tray. Therefore, the multi-cable effect should be investigated. In this paper, the multi-cable effect was examined by using the scale model. The 0.5 times scale model was constructed in the semi-anechoic chamber, and the maximum common-mode (CM) current was measured by changing position along with the cable. The measured result was agreed with the result using the full-size original model. The experiment by using five cables suggested that the influence by the conductive loss and the dielectric loss of cable was not large for the maximum CM current, and the CM current was dominated by the cancellation effect of the in-phase currents flowing on the cables. The investigation for dependency of the position of the signal apply was indicated that the effect can be roughly estimated from the current division factor.

DOI： 10.1109/EMCEUROPE48519.2020.9245704

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記述言語：日本語   掲載種別：研究論文（学術雑誌）

<p>The authors propose a new and more efficient method to search for fault points by injected short pulse with high frequency into distribution line. This method, which is called as TDR measurement, enables to find the fault point easily by measuring propagation time of the pulse reflected due to impedance change at the fault point. In this paper, the proposed method is experimented in real-scale distribution system with about 700m distance which is isolated by DAS (Distribution Automation System) as outage area. The measurement result shows that an injected pulse with corresponding to utility pole span resolution is able to propagate through about 700m distance, and each reflected wave by several brunches and terminals is observed clearly in the real-scale distribution system. And the measurement result corresponds with the simulation result of the test equivalent circuit model. Moreover, the authors measured reflected waves from a fault point (short circuit, broken wire, or grounding) in test circuit. As the results, reflected waves from every fault point were confirmed by simulation, and they depend on the fault type. We calculated the fault location from the pulse velocity and the propagation time of the reflected wave, and the result nearly corresponded to the actual setting. In addition, the measured wave corresponds to the simulation result using equivalent circuit model of each fault point.</p>

DOI： 10.1541/ieejpes.140.662

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記述言語：英語   掲載種別：研究論文（学術雑誌）

<p>The analysis method using the chain parameter matrix (F-matrix) has been proposed for calculating radiated emission from the cable used by power line communication (PLC). In this paper, the radiation resistance was implemented to the F-matrix as the load of the common mode current which was converted from the differential mode PLC signal by the unbalance of the transmission system and was considered as the emission source. The calculated result for the simple cable model was compared to the measurement value and to the calculation value of which the radiation resistance was not considered. The investigation result indicated that the influence of radiation resistance appeared at the frequency where the high radiated emission was observed.</p>

DOI： 10.1587/comex.2020XBL0070

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CiNii Research

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担当区分：責任著者   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）

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）

© 2020 IEEE. The common-mode filter (CMF) is a key device for suppressing emissions radiated from telecommunication cables. Recent serial interfaces deliver the necessity of considering that common-mode (CM) disturbances are converted from the differential mode (DM) telecommunication signals by a CMF. To examine this phenomenon, this study investigated the S_{\text{cd}21} characteristic, which is one of the mixed-mode S-parameters. Two types of CMFs whose S_{\text{cd}21} were different were examined. A signal was supplied to an unshielded twisted pair (UTP) cable through the CMF. The emission from the cable was measured using a setup complying with CISPR 25. Then, the relationship between the ratio of CM to DM signals and the emission level was investigated. The results showed that the emission level decreased as a result of employing the lower S_{\text{cd}21} CMF and that the emission level was linearly proportional to the ratio of the CM to DM signals. The results indicate that {S}_{\text{cd}21} is an essential parameter with which to evaluate CMFs used in telecommunication ports of serial interfaces.

DOI： 10.1109/EMCSI38923.2020.9191645

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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）

© 2020 IEEE. The differential mode impedance (DMZ) and the longitudinal conversion loss (LCL) are important parameters to introduce high-speed power line communication (PLC) systems. Therefore, we should evaluate the DMZ and LCL in a factory environment because the three-phase power distribution system has been employed in factories. The admittance matrix elements at the power distribution board were determined from S-parameter measured with a vector network analyzer. An isolation probe was developed to measure S-parameters under high voltage applying conditions. Measurements were carried out at 60 points in 4 factories. The admittance matrix was represented by the equivalent circuit composed by six impedances, then the DMZ and the LCL were calculated from the mean value of the impedances. The results showed that the absolute value of DMZ was lower than the characteristic impedance of the PLC transmission line, and the LCL value was similar to the LCL in house environment where a two-phase power distribution system was employed.

DOI： 10.1109/ISPLC48789.2020.9115393

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担当区分：責任著者   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）

© 2019 IEEE. Characteristics of radiated emission from the three-wire power cable where the power line communication signal was transmitting was studied by using circuit theory. The simple model whose length was 14.4m was used for the investigation, and the radiated emission was calculated and measured. The average deviation between the calculated data and the measured data was -3.6dB and the standard deviation was 3.3dB. The calculation results indicated that the maximum magnetic field strength could be estimated from the maximum common-mode current. The analysis also suggested that the maximum common-mode current of a three-wire cable was less than that of a two-wire cable in many cases.

DOI： 10.1109/EMCEurope.2019.8872015

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記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

さまざまなモノがインターネットに接続されるIoT 時代において，無線通信だけでなく有線通信も重要な技術の一つである。たとえば，自動車を考えてみても，自動運転やADAS の普及により，車載Ethernet などの高速通信技術の開発が進んでいる。一方，EV/HEV の普及により車内の電磁ノイズ環境は一層厳しいものになっている。車載通信はこれらの電磁妨害波がある環境においても十分に高い信頼性を実現しなければならない。
本講演では，上記のような複数のシステム間の電磁的干渉（EMC）に関して，事例を踏まえて紹介する。特に，特徴的な電磁ノイズがディジタル通信にどのように影響するかを説明し，干渉低減法を紹介する。

DOI： 10.12792/iiae2019.001

CiNii Article

CiNii Research

記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

現在，500mを超える長距離区間で電力線通信(PLC)を使うケースが増えている。そのため電力線ケーブルの高周波透過特性を調べることが必要である。本報告ではVVFケーブルとEEFケーブルの透過特性を測定した。全帯域を使える長さはVVFケーブルでは0.3 kmであるが，EEFケーブルでは1.5k mである。よって長距離通信ではEEFケーブルを用いることが望ましい。今後は他のケーブルも測定することでより良い透過特性を持つケーブルの検証を実施する。

DOI： 10.12792/iiae2019.022

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 1986-2012 IEEE. A control strategy based on matching the source and load changes of the order of milliseconds, called peer-to-peer energy transfer, is introduced. This energy transfer enables a decoupled energy transfer system in common bus networks. To realize the transfer with a pair of two-port circuits, a power gyrator is derived from the phasor-based model of a bidirectional ac/dc converter, based on the concept of a time-variable transformer. Power-gyrator timing synchronization is achieved by communication, and a peer-to-peer energy transfer system is developed. Experimental and simulation results are compared, and it is demonstrated that peer-to-peer energy transfer can be used for decoupling common bus voltage networks.

DOI： 10.1109/TPEL.2018.2882129

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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）

© 2019 The Institute of Electronics, Information and Communication Engineer. Electromagnetic field radiated from Power Line Communication (PLC) which was applied to three wires system was examined with Method of Moments (MoM). The influence of the wire configuration and the terminating condition of the third wire was also evaluated. Calculated common mode current and electromagnetic field intensity agreed well with measured results. The calculation results showed that electromagnetic field intensity decreased or didn't change from two wires system when the third wire was connected to the ground.

DOI： 10.23919/EMCTokyo.2019.8893771

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担当区分：筆頭著者   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）

© 2019 The Institute of Electronics, Information and Communication Engineer. Modal analysis of a multi-channel differential transmission line is discussed for estimation of far-end crosstalk. A simple formula to evaluate the far-end crosstalk was derived using eigenmode and mixed mode S parameter. The accuracy of the proposed formula was verified by comparison with a full wave simulation. The far-end crosstalk of test four-channel differential lines was calculated by the derived formula. These results were in good agreement with that obtained by full-wave simulation. In addition, position of the differential transmission line with low crosstalk was determined using the proposed method.

DOI： 10.23919/EMCTokyo.2019.8893837

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記述言語：日本語   掲載種別：研究論文（学術雑誌）

DOI： 10.14923/transcomj.2018PEP0007

記述言語：日本語   掲載種別：研究論文（学術雑誌）

DOI： 10.14923/transcomj.2017pei0002

記述言語：英語   掲載種別：研究論文（研究会，シンポジウム資料等）

<p>近年,自動運転技術などの発達により,車載通信の大容量化が求められている.この要求に対して,通信容量が比較的大きいEthernetを車載用途に転用する動きがある. Ethernetはオフィスや家庭で使用されてきたため,車載用途と比較して信頼性要求は高くない.</p><p></p><p>そこで本研究では,信頼性の評価方法を定めるため,Ethernetが弱点とする妨害波のパラメータを探ることを目的とした.そのために,妨害波として差動のパルス電圧を通信中のEthernetケーブルに対して印加し,その妨害波のパラメータとパケットエラーレートの相関を調査した.この論文ではその結果を報告する.</p>

DOI： 10.11486/ejisso.33.0_12C2-04

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記述言語：英語   掲載種別：研究論文（研究会，シンポジウム資料等）

<p>PLCなど電力線上の高周波電流を測定する際、低周波電流による磁気飽和をしないロゴスキーコイルを用いる必要がある。</p><p></p><p>本論文では、モーメント法を用いた電磁界解析プログラムであるNEC2によるシミュレーションにより伝達インピーダンスを求め、所望の高周波電流を測定できるロゴスキーコイルを設計した。</p><p></p><p>設計したロゴスキーコイルを作製・評価し、電力線上のPLC信号の電流測定を行った。</p>

DOI： 10.11486/ejisso.33.0_11D3-02

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CiNii Research

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記述言語：英語   掲載種別：研究論文（学術雑誌）

<p>The relation between maximum common mode current and maximum radiated magnetic field strength was experimentally studied using a simple power distribution line model. The common mode current was measured along the cable and the radiated magnetic field strength was measured around the model. They were evaluated using the <i>S</i>₂₁ parameter. The frequency characteristic of both the maximum current and the maximum strength showed a closely similar pattern. Our evaluation of their correlation indicated that the relation between the maximum common mode current and the maximum radiated magnetic field strength could be represented by a straight line, and that 80% of the measured data was contained within 2 dB of the regression line.</p>

DOI： 10.1587/comex.2019XBL0004

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記述言語：日本語   掲載種別：記事・総説・解説・論説等（その他）

DOI： 10.5104/jiep.22.622

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記述言語：英語   掲載種別：研究論文（学術雑誌）

Copyright © 2018 The Institute of Electronics, Information and Communication Engineers. This paper describes the equivalent-circuit model of a metamaterial composed of conducting spheres and wires. This model involves electromagnetic coupling between the conductors, with retardation. The lumped-parameter equivalent circuit, which imports retardation to the electromagnetic coupling, is developed in this paper from Maxwell’s equation. Using the equivalent-circuit model, we clarify the relationship between the retardation and radiation loss; we theoretically demonstrate that the electromagnetic retardation in the near-field represents the radiation loss of the meta-atom in the far-field. Furthermore, this paper focuses on the retarded electromagnetic coupling between two meta-atoms; we estimate the changes in the resonant frequencies and the losses due to the distance between the two coupled meta-atoms. It is established that the dependence characteristics are significantly affected by electromagnetic retardation.

DOI： 10.1587/transele.E101.C.923

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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）

© 2018 IEICE In this paper, we propose a single-conductor transmission line model with external excitation. It is expressed basically as the wave equation for the variables of linear charge densities and currents, but added by an excitation term of external electric fields. We theoretically derive electric fields generated by terminal discontinuity and incorporate them into the proposed equation as feedback. The model is tested against Method of Moments (MoM) and we confirmed its validity.

DOI： 10.23919/APMC.2018.8617551

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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）

© 2018 IEICE We describe a topological approach for the analysis of meta-atoms. We focus on the star structure of wired metallic spheres and represent the dynamics by the equivalent circuit model in which the incident matrix of the circuit corresponds to the topology of wires. We show that all the resonant frequencies of the structures are approximately found by the graph Laplacian of the wire structures.

DOI： 10.23919/APMC.2018.8617226

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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）

© 2018 IEEE. Detection of a fault point in an overhead distribution system is necessary for accident restoration in power grid. Applying a pulse wave to the overhead distribution line and measurement of reflection wave, which is called TDR measurement with utility-pole-interval resolution, can detect distance to the fault point. In this report, an overhead distribution line is treated as a three-conductor transmission line with earth ground. Eigen modes in the transmission line are derived by inductances and capacitance matrices calculated by electrostatic or magnetostatic simulator. In addition, a fundamental matrix of an equivalent circuit model of a fault point is expressed by impedances and admittances. The fundamental matrix is converted to a modal S parameter. Reflection coefficient with mode conversion of disconnection fault case is calculated using derived S parameter. The calculated reflection coefficients are in good agreement with calculation results using a circuit simulator. As a results, considering mode conversion in the TDR method can detect type of fault in the overhead distribution lines.

DOI： 10.1109/ISEMC.2018.8393833

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担当区分：責任著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

The electric asymmetry of a pair of differential transmission lines placed near an adjacent ground edge causes unwanted electromagnetic radiation when the adjacent ground width changes. In this paper, the imbalance difference model which has been proposed by the authors is verified by experiment and fullwave simulation for asymmetric differential transmission lines at different distances from the adjacent ground edge. The difference in secondary-common mode current in terms of the distance from the ground edge coincides with an error of up to 3 dB among the imbalance difference model, measurement, and electromagnetic simulation. Therefore the imbalance difference model has sufficient accuracy for practical use in designing differential transmission lines which produce less undesired emissions.

DOI： 10.5104/jiep.21.178

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2012 IEEE. Recently, a series of EMC standards for bus transceiver ICs, IEC 62228, which focuses on automotive applications, has been greatly attracting attention. In particular, the importance of immunity characteristics is increasing to ensure safety and reliability. In this article, the latest trends for IEC 62228 series are introduced; particularly, automotive Ethernet is focused on among automotive network devices, and the importance of using pulse disturbance in immunity testing for Ethernet is considered. The influence of pulse disturbance on the communication quality of 100BASE-TX was evaluated experimentally, and the relationship between the threshold level of Ethernet and pulse disturbance affecting communication quality was revealed when the amplitude and width of pulse disturbance were changed. In particular, disturbance with a pulse width of about the same as 1-bit time degraded communication quality the most.

DOI： 10.1109/MEMC.0.8339542

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2012 IEEE. Designing electronic devices in consideration of EMC is very important, especially in the case of using the devices in cars. Because of this, standards for evaluating the EMC of bus transceivers equipped in cars are focused on. The authors are currently researching CAN FD transceivers and carried out an RF immunity test by using the DPI method to investigate the reason for CAN FD communication errors. In a test on the CAN bus, the maximum variation in differential voltage was 1 V, although the common mode voltage on the CAN bus was 40 V. Therefore, the CAN FD could communicate with the other one. In a test on power-supply terminals, an error was observed just after the change in bitrate in the middle of a CAN FD data-frame. It is shown that the short bit time was the reason for the error.

DOI： 10.1109/MEMC.0.8339543

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記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2018 The Institute of Electrical Engineers of Japan. It is necessary to detect a fault point in overhead distribution system for failure restoration. To search the fault point effectively and precisely, we apply TDR (Time Domain Reflectometry) measurement with utility-pole-distance resolution. In this method, we inject a pulse wave into distribution lines and measure the reflection. In this paper, the authors confirm propagation characteristics of overhead distribution system and compare the measurement of the reflected wave with the simulation result. Through the experiments, the authors confirm an influence of parasitic capacitances in overhead distribution facilities such as a transformer and a switchgear. When distribution facility is not connected with distribution line, the reflected wave from every utility pole and the end terminal are observed; the reflected waves from every utility pole are caused by parasitic capacitors between the distribution lines and cross arms. When distribution facility such as a transformer and a switchgear is connected with distribution line, the reflected waves caused by these facilities are observed. As a result, we confirmed that parasitic capacitances of distribution facilities affect the propagation characteristics of distribution failure pulse wave. In addition, the authors developed a simulation tool to evaluate the propagation characteristics of the pulse wave in the overhead distribution system based on the result utilizing the test distribution system, and confirmed that the simulation results corresponded to the measurement results.

DOI： 10.1541/ieejpes.138.766

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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）

© 2018 Electromagnetics Academy. All rights reserved. To design electromagnetic phenomena in complex metallic structures such as metamaterials, it is useful to analyze them by equivalent circuit models. Although general equivalent circuit models do not have retardations of electromagnetic couplings, the model derived theoretically from Maxwell's equation includes the retardation. The retardation causes the singularity on the light line of the dispersion curve. In order to find the dispersion curve, we usually pick up the most dominant root in the infinite characteristic roots. However, considering the other characteristic roots, we find another dispersion curve and clarify the coupling between the light line and plasmonic modes.

DOI： 10.1109/PIERS-FALL.2017.8293540

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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）

© 2017 IEEE. Now voltage sources are widely used for differential signaling. However, a common mode current is excited in unbalance differential transmission line. In this paper, common-mode excitation by differential current sources is compared with that by differential voltage sources in the unbalanced differential transmission line. A equivalent circuit describing the differential transmission line are used for evaluation of common mode current generated by the differential voltage or current sources. As a result, by using the current sources, the primary common mode current can be reduced by about 15 dB at 100 MHz than that of the voltage sources.

DOI： 10.1109/EMCEurope.2017.8094707

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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）

© 2017 The Institution of Engineering and Technology. All rights reserved. A new method for locating fault point by injecting high-frequency short pulse into overhead distribution line is attempted in this study. This method, which is called as time-domain reflectometry (TDR) measurement, enables to find the fault point easily by measuring propagation time of the pulse reflected due to the impedance change at the fault point. In a prior research, propagation characteristics of injected pulse through the experiment in test circuit have been confirmed. In this study, the result of the experiment on TDR measurement in real-scale distribution system has been explained. As a result, application of the method in real-scale distribution system has been confirmed. Moreover, different characteristics based on fault type for reflected waves at fault points, such as short circuit, grounding, or broken wire, have been confirmed.

DOI： 10.1049/oap-cired.2017.0195

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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）

© 2017 IEEE. Transient analysis of an electrostatic discharge (ESD) is important for development of a highly immune device and an IC. High nonlinearity of an ESD protection circuit makes it difficult to simulate transient waveform of ESD. In this manuscript, a nonlinear model of a zener diode as ESD protection device is proposed for transient simulation of ESD. In the proposed model, voltage-dependence of a series resistance and a diffusion capacitance are represented by approximation formulae. In order to evaluate the proposed model, transient waveforms are calculated using SPICE model and the proposed model when ESD current specified by IEC 61000-4-2 is injected into the zener diode. By comparison with these waveforms, the calculation results by the proposed model is in good agreement with that by SPICE model.

DOI： 10.1109/EMCCompo.2017.7998101

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記述言語：日本語   掲載種別：研究論文（学術雑誌）

IoT時代の到来や5G構想により，利用する通信環境やアプリケーションに応じて，最適な通信方式や通信パラメータを選択する利便性の高いアクセス制御が求められており，最適な通信方式や通信パラメータの選択には，通信環境に応じて実現できる通信品質をあらかじめ推定できることが重要となる．通信環境を決定する要因の一つに妨害波があり，ディジタル無線通信の通信品質劣化と相関の高い振幅確率分布（APD）や信号と妨害波の電力比（SIR）を用いて，妨害波の存在する通信環境における通信品質を推定する手法が提案されている．一方，人工的な妨害波の多くはパルス性妨害波であるが，APDには，妨害パルスの持続時間や妨害パルス間のインターバルを考慮することができない等の課題があり，SIRを用いる場合も，複数の妨害源が混在し，妨害パルスごとに妨害波電力が異なる状況においては必ずしも有効とは言えない．本論文では，様々なディジタル無線変調方式に適用可能なパケット通信を想定し，妨害パルスごとに，パルス持続時間，パルス間インターバル，及び妨害波電力の異なる通信環境において，妨害パルスとパケットの衝突確率を考慮したパケット誤り率（PER）解析方法を提案する．更に，提案手法を用いたケーススタディにより，パルス持続時間及び妨害波電力の異なる妨害パルスが一定間隔でランダムに存在する通信環境において，PERへの影響を推定する際に必要な妨害波のパラメータについても考察する．

DOI： 10.14923/transcomj.2016pep0008

CiNii Research

記述言語：英語   掲載種別：研究論文（学術雑誌）

© 2017 The Institute of Electronics, Information and Communication Engineers. An equivalent-circuit model is an effective tool for the analysis and design of metamaterials. This paper describes a systematic and theoretical method for the circuit modeling of meta-atoms. We focus on the structures of wired metallic spheres and propose a method for deriving a sophisticated equivalent circuit that has the same topology as the wires using the partial element equivalent circuit (PEEC) method. Our model contains the effect of external electromagnetic coupling: excitation by an external field modeled by voltage sources and radiation modeled by the radiation resistances for each mode. The equivalent-circuit model provides the characteristics of meta-atoms such as the resonant frequencies and the resonant modes induced by the current distribution in the wires by an external excitation. Although the model is obtained by a very coarse discretization, it provides a good agreement with an electromagnetic simulation.

DOI： 10.1587/transele.E100.C.305

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記述言語：日本語   掲載種別：研究論文（学術雑誌）

DOI： 10.11486/ejisso.31.0_320

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記述言語：英語   掲載種別：研究論文（学術雑誌）

<p>In this paper, in order to improve the reliability of Ethernet communication, the effect of pulse disturbances on the communication quality of 100BASE-TX was evaluated experimentally. A relationship between the threshold level of Ethernet and disturbances affecting communication quality was revealed when the amplitude and width of the pulse disturbance were changed. A disturbance in which the pulse width was the same as 1 bit time of the signal degraded the communication quality the most. These findings should help in the effort to apply Ethernet to automotive area network.</p>

DOI： 10.1587/comex.2017XBL0116

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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）

© 2016 IEEE. This paper describes a time domain model for current and charge density on thin cut wire structures. The model represents the reaction of radiation from the cut wires with retarded couples which express the loss, and the validity of the model is confirmed by comparing it with electromagnetic simulations. Since the model gives the reaction of the radiation only by near field coupling in time domain and provides a physical insight of the radiation, we can easily estimate the reactions of the radiation from thin-wire structures.

DOI： 10.1109/MetaMaterials.2016.7746480

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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）

© 2016 IEEE. In order to estimate undesired behaviors in ICs due to RF conducted electromagnetic disturbances, immunity macro models are necessary for prediction of malfunction at front-loading of the design process. In this paper, a mechanism of malfunction of an LDO (low dropout) voltage regulator is investigated from the aspect of the internal terminal in a circuit. Measurement results show that the DC drift of the internal reference voltage is the dominant factor in malfunction of the LDO voltage regulator used in this study. In addition, an immunity macro model called ICIM-CI considering internal functional blocks is proposed. The model consists of PDN (passive distribution networks) for representing the transmission and reflection characteristics of RF disturbance and IB (immunity behavior) describing relation between malfunction of IC and the reference voltage (an internal terminal voltage of the LDO voltage regulator). The proposed model can predict variation of immunity behavior when a bypass capacitor is added near the injection terminal of RF disturbance. The simulation results using the proposed model is in good agreement with measurement results.

DOI： 10.1109/EMCEurope.2016.7739228

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担当区分：筆頭著者   記述言語：日本語   掲載種別：研究論文（研究会，シンポジウム資料等）

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記述言語：日本語   掲載種別：研究論文（学術雑誌）

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記述言語：日本語   掲載種別：研究論文（学術雑誌）

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記述言語：日本語   掲載種別：研究論文（学術雑誌）

DOI： 10.11486/ejisso.30.0_338

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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）

© 2013 IEEE. A method to reduce common-mode current flowing on a wire harness attached to a printed circuit board is proposed in this paper. In this method, SMD inductors are placed on a power supply line and/or a ground line on a LSI package with floating conductor to control balance of impedance of the power distribution network, and the common-mode current can be reduced. The common-mode voltage is reduced about 20 dB with the package proposed in this paper.

DOI： 10.1109/APEMC.2013.7360608

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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）

© 2015 IEEE. Because predicting undesired behaviors in IC (Integrated Circuit) due to conducted electromagnetic disturbances is necessary for front-loading the design process, immunity models are becoming more important to predict a malfunction at the design stage of electronic products. In this paper, the failure to function mechanism in a LDO (Low Dropout) voltage regulator is investigated from the aspect of the internal terminal in a circuit. Simulations confirm a relation between the internal reference voltage and the DC shift error at certain frequencies. Thus, monitoring the voltage or current at an internal terminal between functional blocks gives useful information about an IC model to predict immunity.

DOI： 10.1109/EMCCompo.2015.7358346

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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）

© 2015 IEEE. Conducted disturbances from communication or power supply cables affect Ethernet devices. A conducted disturbance, which is generated when several switching power devices reach a communication device, degrades the quality of signal communications. In addition, a disturbance passing through an Ethernet device influences neighboring devices connected by the communication cables. Herein we propose a system to measure the propagation modes of conducted disturbances in power supply cables and Ethernet cables. The results indicate that mode conversion occurs in not only an Ethernet hub but also an AC adapter supplying DC voltage to Ethernet devices. The conducted disturbance to the AC and DC power supply cable is strongly transmitted to the Ethernet cable as the primary common mode and the differential mode. Conversion from the common mode in the power supply cable to the primary common mode in the Ethernet cable is dominant in the measured frequency range.

DOI： 10.1109/ISEMC.2015.7256190

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記述言語：日本語   掲載種別：記事・総説・解説・論説等（学術雑誌）

DOI： 10.5104/jiep.18.348

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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）

© 2015 The Japan Institute of Electronics Packaging. In this paper, a mechanism of common mode noise generation in a full bridge converter is discussed, and a reduction method is proposed. Common mode noise is generated due to parasitic capacitors around power MOSFETs. In order to explain the mechanism of common mode generation, an equivalent circuit with the parasitic capacitors is proposed. When the circuit satisfies the impedance balance condition, the common mode noise can be eliminated. However, the impedance balance condition is time-varying because a full bridge converter changes the circuit topology during the operation of the circuit. Therefore, large capacitors are inserted for keeping the current paths dominant, and making input impedance of AC side high is applied in order to form the topology satisfying the impedance balance condition. The effectiveness of this method is verified by measurement, and the common mode current in DC side is reduced about 26 dB.

DOI： 10.1109/ICEP-IAAC.2015.7111100

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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）

© 2014 The Institute of Electronics, Information and Communication Engineer. We derived expressions of power and ground voltage noises for reducing common-mode voltage in a power distribution network of an LSI and found that they have the same amplitude and a phase difference approaching 180°. To confirm this, we performed an experiment using a test board with a cover-metal structure-essentially, a floating conductor in an LSI package to reduce common-mode voltage. The evaluation was performed using an instrument that can measure the amplitude and phase difference of two channels in synchronization and calculate common-mode and differential-mode voltages. Results demonstrated phenomena similar to the expressions we derived.

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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）

© 2014 The Institute of Electronics, Information and Communication Engineer. At a differential transmission line bend, a differential mode propagated in a differential transmission line is converted to a common mode due to asymmetry of the transmission line. The common mode conversion leads to problems with signal integrity. We propose a method to improve electric symmetry of the transmission line bend and thus reduce the common mode conversion. The self-capacitance and inductance of one line are different from those of another. In order to fit those parameters, the narrowing signal line for increasing self-inductance and placing a conductor shape which is like a stub are used to reduce the imbalance degree of the transmission line bend. We obtained a 20-dB reduction of common mode excitation by optimizing the signal line width and stub length. In addition, an equivalent circuit model for the transmission line bend is proposed to evaluate the reduction. The simulation results using the proposed equivalent circuit model are in good agreement with the results obtained by the 3D electromagnetic solver.

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担当区分：筆頭著者   記述言語：英語   掲載種別：研究論文（学術雑誌）

Asymmetry in a differential transmission line bend generates a large common mode, which leads to signal integrity issues. Herein two methods are proposed to improve the symmetry and reduce the common-mode at the line bend on a printed circuit board. Placing a guard trace near a narrowed inner signal line at the line bend results in a 15-dB reduction of the common mode. Alternatively, employing a stub connected to the inner signal at the bend section results in a more than 20-dB reduction.

DOI： 10.1587/comex.3.295

CiNii Article

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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）

A differential transmission line bend generates a large common mode due to its asymmetry, and it leads signal integrity problems. In this paper, the imbalance difference model, which was proposed by the authors for estimation of common-mode radiation, is extended to apply to the differential signaling systems. An equivalent circuit model based on the imbalance difference model is proposed for estimation of the common-mode excitation at the bent area. Simulation results of mode conversion from the differential mode to the common mode calculated by the proposed model are in good agreement with those using a three-dimensional electromagnetic solver. In order to reduce the common mode, a guard trace is added near the narrowed inner signal line at the bent area and it gives 15 dB of reduction of the common mode. © 2013 EMC Europe Foundation.

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記述言語：日本語   掲載種別：研究論文（学術雑誌）

屈曲した差動伝送線路では、構造的な対称性の欠如によりコモンモードが発生し、信号品質の悪化を引き起こす。伝送線路におけるコモンモード発生について平衡度不整合理論を用いた説明がなされているが、本報告ではこの理論を拡張し、差動伝送線路の屈曲部におけるコモンモード変換を予測する等価回路モデルを提案した。提案する等価回路モデルでは、伝送線路の直線部は仮想的なモード伝送線路で表現し、屈曲部近傍は集中素子で表現する。それらの接続は理想変成器で行う。提案モデルを用いた回路計算により得たコモンモード発生量は、3次元電磁界解析により得られたコモンモード発生量と1dB以内の誤差で一致した。また、屈曲部の平衡度(電気的対称性)を向上させるために、ガードトレースを用いる方法とオープンスタブを配置する方法を検討し、それぞれ約15dBおよび約20dB程度のコモンモード発生抑制を実現した。

CiNii Article

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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）

Substrate noise coupling from digital circuits causes degradation of performance of analog circuits on the same LSI chip. Generally large area on the chip is necessary to reduce the substrate coupling. In this paper, a proposed method eliminates the substrate coupling by extension of the impedance balance control technique which was proposed by the authors. The impedance balance condition on the LSI chip is satisfied by tunable resistances inserted into the substrate contacts. Even if the substrate coupling between two circuits is low (for example, 70 ω,) the substrate noise coupling was reduced enough on the condition of impedance balance. © 2013 IEEE.

DOI： 10.1109/EMCCompo.2013.6735168

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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）

Simultaneous switching current of a CMOS circuit causes power and ground bounces. The voltage fluctuation is injected into the CMOS substrate, and it degrades the performance of the circuit operation. In this report, we focus on the fact that parasitic couplings in the CMOS substrate and parasitic inductance in the power and ground connection form a bridge circuit, and we demonstrate that the voltage bounce can be suppressed by controlling variable resistances that are inserted between the substrate resistive coupling and the conductor line for the DC supply. The effectiveness of this method is verified with a scaled quad flat package (QFP) and we reduced the measured voltage bounce about 40 dBμV. © 2013 IEEE.

DOI： 10.1109/EMCCompo.2013.6735187

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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）

In this paper, we discussed the reproducibility of the direct RF power injection method. Transmission and reflection characteristics of the measurement setup affected the evaluation of immunity. Also, the common-mode generation at the connection of the DC supply cable should be reduced using the common-mode absorption devices. © 2013 IEEE.

DOI： 10.1109/EMCCompo.2013.6735173

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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）

When an LSI package is mounted on a PCB, parasitic couplings are unintentionally generated between them. Antiresonance of these couplings (package-common-mode resonance) can cause degradation of signal and power integrity. In this paper, the authors experimentally verified the package-common-mode resonance by comparing scattering parameters with variation of CMOS output jitter. In order to suppress increase of the jitter, resister-dumping method was tested as a countermeasure. © 2012 IEEE.

DOI： 10.1109/EMCEurope.2012.6396871

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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）

The authors proposed a method to reduce the common-mode current flowing on a wire harness attached to a printed circuit board (PCB). In this method, SMD inductors are placed on a power supply line and/or a ground line on a PCB to control balance of impedance of the power distribution network, and the common-mode current can be reduced. In this paper, the authors apply this reduction method to an LSI package, and propose a new structure of the LSI package with floating conductor which is called cover metal. The common-mode voltage is reduced about 20 dB with the package proposed in this paper. © 2012 IEEE.

DOI： 10.1109/EDAPS.2012.6469405

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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）

In a differential transmission line, a large common-mode current is excited due to its asymmetry. In this paper, the authors demonstrate experimentally the common-mode current and verify the imbalance difference model that was proposed for prediction of the common-mode current reduction. Experimental results show that the reduction of common-mode current of about 20 dB is achieved by changing the position of the transmission line. In addition, the differences that are calculated using the imbalance difference model are in agreement with the measured ones within 2 dB. © 2012 IEEE.

DOI： 10.1109/APEMC.2012.6237956

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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）

Package-common-mode resonance which is caused by a parasitic capacitance and a parasitic inductance between package and PCB grounds degrades signal and power integrity. A parasitic capacitance between a package ground and a PCB ground resonates with a parasitic inductance at ground connections, such as solder balls in a BGA package. In this paper, the authors simulate ground bounce due to the package-common-mode resonance caused by external conductive noise in a power supply system. The ground bounce degrades signal integrity of CMOS output signal. The authors demonstrated an increase in jitter of CMOS output at the package-common-mode resonance frequency. © 2012 IEEE.

DOI： 10.1109/APEMC.2012.6237999

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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）

Package-common-mode resonance which is caused by a parasitic capacitance and parasitic inductances between package and PCB grounds makes degradation of signal and power integrity. A parasitic capacitance between a package ground and a PCB ground anti-resonates with a parasitic inductance at ground connections such as solder balls in a BGA package. In this resonance, currents flow on power and ground lines in the package with the same phase. Thus, the authors name this antiresonance "Package-common-mode resonance". The package-common-mode resonance causes the power and/or ground bounce and increase of jitter of the output signal. According to measurement results of test boards, the resonance frequency is depend on the number of ground connection because the parasitic inductance is decreased by increasing ground connection. For example, the resonance frequency was changed from 575 MHz to 862 MHz in the test board when the number of the ground connection was decupled. © 2011 Univ of Zagreb.

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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）

To simulate power supply noise of an LSI, an EMC macro-model, LECCS-core, is under development. The LECCS-core model consists of a linear equivalent circuit and equivalent current sources. In this paper, program-dependent current elements are extracted for functional blocks of a microcontroller. By combining these component currents with considering the program sequence, the power supply current is simulated both in time domain and frequency domain. Even when the LSI runs different programs with different clock frequencies, noise spectra consisting of harmonics and sub-harmonics are reproduced in good agreement with measured data. © 2011 Univ of Zagreb.

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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）

In a differential transmission line, a large common-mode radiation is excited due to asymmetry. To suppress the radiation, the differential line must be designed electrically symmetric. In this paper, the imbalance difference model, which was proposed by the authors for estimation of common-mode radiation, is extended to apply the differential signaling system. The authors focus on two pairs of differential transmission lines with asymmetric property, which consists of an adjacent return plane and signal lines which are placed close to an edge of the return plane. The authors define five transmission modes; two normal modes, two primary common modes and a secondary common mode. In these transmission modes, the secondary common mode radiation is dominant, and the authors evaluate the radiation using the imbalance difference model. To reduce the common-mode radiation, placing a guard trace which has the same potential as that of the return plane, we can control the imbalance and reduce common-mode radiation even the transmission line has asymmetry. The reduction of common-mode radiation can be estimated quantitatively by calculation of the imbalance of the transmission line. ©2010 IEEE.

DOI： 10.1109/ISEMC.2010.5711310

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記述言語：英語   掲載種別：研究論文（学術雑誌）

We propose a novel technique of matching at both ends of the guard trace to suppress resonance. This approach is derived from the viewpoint that the guard trace acts as a transmission line. We examined that matched termination suppresses guard-trace resonance through simulating a circuit and measuring radiation. We found from these results that the proposed method enables guard-trace voltages to remain low and hence avoids increases in radiation. In addition, we demonstrated that "matched termination at the far end of the guard trace" could suppress guard-trace resonance sufficiently at all frequencies. We eventually found that at least two vias at both ends of the guard trace and only one matching resistor at the far end could suppress guard-trace resonance. With respect to fewer vias, the method we propose has the advantage of reducing restrictions in the printed circuit board layout at the design stage. © 2010 The Institute of Electronics, Information and Communication Engineers.

DOI： 10.1587/transcom.E93.B.1746

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記述言語：英語   掲載種別：研究論文（学術雑誌）

An EMC macro-model for LSIs, named the LECCS-core model, is under development for simulating high frequency noise in power supply currents. In this paper, the conventional LECCS-core model is extended by adding resistances in the ground connection of an LSI, in order to separate the core block and the analog block. The model parameters are identified using symbolic analysis and least-square optimization. Using this new model, the transfer impedances between different power supply pins can be simulated accurately. Additionally we derived the equivalent internal current sources by using that model. As a result, we confirmed that the internal current sources were improved. In conclusion, we confirmed that the configuration of the linear equivalent circuit and our modeling method can be applied widely to microcontrollers of the same block configuration. © 2010 The Institute of Electrical Engineers of Japan.

DOI： 10.1541/ieejeiss.130.1897

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記述言語：英語   掲載種別：研究論文（学術雑誌）

In a differential transmission line, a large common-mode radiation is excited due to its asymmetry. In this paper, the imbalance difference model, which was proposed by the authors for estimation of common-mode radiation, is extended to apply to the differential signaling systems. The authors focus on a differential transmission line with asymmetric property, which consists of an adjacent return plane and two signal lines which are placed close to an edge of the return plane. Three orthogonal transmission modes, a normal mode, a primary common mode and a secondary common mode, are defined. Among these transmission modes, the secondary common mode is dominant in radiation, and a mechanism of the secondary common-mode generation is explained. The radiated emission which was calculated using the imbalance difference model was in good agreement with that obtained by full wave calculation. © 2010 The Institute of Electronics, Information and Communication Engineers.

DOI： 10.1587/transcom.E93.B.1739

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CiNii Article

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