Crosstalk Simulation for Parallel Microstrip Lines with a Nonlinear Capacitive Load Using the Dynamic C-V Characteristic

Crosstalk analysis is getting more important for avoiding malfunction of circuits. In this paper, crosstalk analysis of parallel microstrip lines with a nonlinear capacitive load is described. A characteristic of the nonlinear capacitive load is changed by a rapidly change of an applied voltage of the load. The change of the characteristic induces a complicated reflected wave that causes complicated crosstalk. To simulate such crosstalk precisely, the dynamic C-V characteristic can be used. However, if the dynamic C-V characteristic is complicated, it takes a long time to simulate the crosstalk by using a conventional method. Thus, a simulation method using a recurrence formula is introduced. The recurrence formula is derived from a function of the dynamic C-V characteristic simply. The calculated results computed by using the introduced method agree with the measured crosstalk and the introduced method is superior in computation time to the conventional method. It is confirmed that the introduced method is effective in crosstalk simulation. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

A quasi‐planar incident wave excitation for time‐domain scattering analysis of periodic structures

We present a quasi‐planar incident wave excitation for time‐domain scattering analysis of periodic structures. It uses a particular superposition of plane waves that yields an incident wave with the same periodicity as the periodic structure itself. The duration of the incident wave is controlled by means of its frequency spectrum or, equivalently, the angular spread in its constituting plane waves. Accuracy and convergence properties of the method are demonstrated by scattering computations for a planar dielectric half‐space. Equipped with the proposed source, a time‐domain solver based on linear elements yields an error of roughly 1% for a resolution of 20 points per wavelength and second‐order convergence is achieved for smooth scatterers. Computations of the scattering characteristics for a sinusoidal surface and a random rough surface show similar performance. Copyright © 2006 John Wiley & Sons, Ltd.     

Principle and application of ball SAW devices

A thin beam of waves usually diverges due to diffraction, which is a limitation of any device using such waves. However, a surface acoustic wave (SAW) on a sphere with an appropriate aperture does not diverge but is collimated, realizing ultra‐multiple roundtrips along an equator of the sphere. This effect is caused by the balance between diffraction and focusing on a spherical surface, and it enables realization of high‐performance ball SAW sensors. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 168(1): 41–51, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20817     

Development of an identification system for location of free metallic particles in GIS based on analysis of Lamb waves

We investigated propagation properties of Lamb waves in a gas‐insulated switchgear (GIS) tank to diagnose insulation performance of GIS. The acoustic signals excited by a free metallic particle colliding with the tank sheath were measured using AE sensors. The wavelet transform was applied to decompose the wave data into its time–frequency components. As a result, difference of propagation properties of Lamb waves is clearly seen with different sizes of GIS tank. Based on the characteristics of Lamb waves, algorithms for location identification of a free metallic particle were examined in model GIS using two AE sensors. Herein, we propose a new system for location identification of a free metallic particle in GIS. Moreover, it is verified that the new identification system is suitable as a diagnostic technique for GIS. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 167(3): 28–35, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20676     

Time‐frequency analysis of a pressure wave caused by impulse tree using wavelet transform

This paper describes results of time‐frequency analysis of a pressure wave caused by impulse tree extension using wavelet transform. Pressure waves were measured by a piezo sensor which was located on the back of the plane electrode when high‐voltage nanosecond pulses were applied to a point electrode in a low‐density polyethylene block. Frequency of the pressure wave from induced charges on the plane electrode was higher than that of the pressure wave from tree. In addition, the frequency of the pressure wave from tree tended to decrease with increasing gap length because of the dispersion of the pressure wave during its propagation. When a large tree extension occurred between a 5‐mm gap, pressure waves of about 10 MHz propagated from the tree tip and a pressure wave of 1 MHz propagated from the tree stem. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 142(1): 1–7, 2003; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10097     

Causes and characteristics of the electromagnetic vibration of a capacitor motor under load

Capacitor motors (CRMs) are widely used to drive industrial equipment and home electric appliances. Recently, reduction of the vibration and noise of CRMs has become increasingly important from the standpoint of environmental improvement. However, electromagnetic vibration of CRMs under load has not been sufficiently analyzed. The present paper theoretically and experimentally discusses the causes and characteristics of CRM electromagnetic vibration under load. The primary conclusions are as follows:

• (1) The general formula for the dominant electromagnetic vibration caused by electromagnetic force waves was derived, including the influences not only of a backward magnetic field but also of magnetic saturation.
• (2) The dominant electromagnetic vibration of CRMs is theoretically attributed to three types of electromagnetic force waves. Two types of electromagnetic force wave are generated by the interaction of two forward magnetic fluxes, such as those of a three‐phase squirrel‐cage induction motor, and the other type of electromagnetic force wave is generated under the influence of a backward magnetic flux.
• (3) The characteristics of the dominant electromagnetic vibration depending on the load and the running capacitance are subdivided theoretically and experimentally into three types based on the characteristics of the electromagnetic force wave and the equivalent circuit current.
• (4) The influences of magnetic saturation in dominant electromagnetic vibration have been verified experimentally and their causes have been clarified theoretically in relation to electromagnetic force waves. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(4): 68–76, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20129

     

Hyperreal waves on transfinite,terminated, distortionless and lossless,transmission lines

A prior work (Graphs and Networks: Transfinite and Nonstandard, Chapter 8. Birkhauser: Boston, Cambridge, MA, 2004) examined the propagation of an electromagnetic wave on a transfinite transmission line—transfinite in the sense that infinitely many one‐way infinite transmission lines are connected in cascade. That there are infinitely many such one‐way infinite lines results in the wave propagating without ever reflecting at some discontinuity. The present work examines the case where the cascade terminates after only finitely many one‐way infinite transmission lines, with the result that reflected waves are now produced at both the far end as well as at the initial end of the transfinite transmission line. The questions whether the reflected waves are infinitesimal or appreciable and whether they sum to an infinitesimal or appreciable amount are resolved for both distortionless and lossless lines. Finally, the generalization to higher ranks of transfiniteness is briefly summarized. Copyright © 2005 John Wiley & Sons, Ltd.     

Wave digital simulation of passive systems in linear state‐space form

This paper deals with wave digital modeling of passive state‐space models. The set of differential equations must be of linear state‐space form, but all parameters can be time‐variant and/or nonlinear. For such state‐space models, a canonical internally passive reference circuit is presented and used for deriving wave digital structures. In order to show the usability, special solutions for important basic linear time‐variant models are compared with wave digital simulation results. Moreover, the wave digital modeling of a nonlinear and time‐variant oscillator is discussed. Especially for a lossless oscillator an implementation is proposed, which preserves energy under finite‐arithmetic conditions. This is verified by comparing simulation results with the analytical solution of a gravity pendulum. Copyright © 2009 John Wiley & Sons, Ltd.     

Sliding mode control for a class of uncertain nonlinear system based on disturbance observer

In this paper, a sliding mode control (SMC) scheme is proposed for a class of nonlinear systems based on disturbance observers. For a nonlinear system, the disturbance that cannot be directly measured is estimated using a nonlinear disturbance observer. By choosing an appropriate nonlinear gain function, the disturbance observer can well approximate the unknown disturbance. Based on the output of the disturbance observer, an SMC scheme is presented for the nonlinear system, and the stability of the closed‐loop system is established using Lyapunov method. Finally, two simulation examples are presented to illustrate the features and the effectiveness of the proposed disturbance‐observer‐based SMC scheme. Copyright © 2009 John Wiley & Sons, Ltd.     

Analysis and implementation of a fourth‐order bandpass filter for R‐wave detection of an implantable cardiac microstimulator

This paper presents an ultra‐low‐power fourth‐order bandpass operational transconductance amplifier‐C (OTA‐C) filter for an implantable cardiac microstimulator used to detect the R‐wave of intracardiac electrograms. The OTA‐C filter fabricated by TSMC 0.35‐µm complementary metal–oxide–semiconductor (CMOS) technology is operated in the subthreshold region to save power under a supply voltage of 1 V. The current cancellation technique is adopted to reduce the transconductance of the amplifier. Through this, the low‐frequency OTA‐C filter can be realized by ultra‐low transconductance with on‐chip capacitors. Direct comparison to conventional RLC ladders replaced by OTA‐C circuits shows that the method of reducing the number of OTAs further diminishes power consumption. Design issues, including ultra‐low transconductance, linearity, and noise, are also discussed. Measurement results show that the low‐voltage, low‐power filter has a bandwidth between 10 and 50 Hz, third inter‐modulation distortion of ?40 dB, dynamic range of 43 dB, and power consumption of only 12 nW. The real electrocardiography signal is fed into the bandpass filter to verify the function of signal processing with the distribution of the R‐wave. Copyright © 2012 John Wiley & Sons, Ltd.     

A new standing‐wave testing system for bridge structure nondestructive damage detection using electromagnetic wave

Several data analysis algorithms exist for detecting damages in bridges; however, such algorithms only approximately locate the damaged areas. To increase the accuracy and sensitivity, a new nondestructive, standing‐wave, bridge‐testing system as well as algorithm is proposed. The proposed system sends 3.8–5.8 GHz modulated sweeping waves to an object, the input and reflected waves form a standing wave, which is used to check and evaluate the state of the object under examination. In comparison with other systems, the proposed system is compact and less expensive, and offers higher sensitivity, higher resolution, and higher accuracy. Simulations and experiments verified its effectiveness. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Consideration of radiated electromagnetic waves from partial discharge based on half‐wave dipole antenna model

Partial discharge (PD) may take place due to residual defects like metallic particles in SF₆ gas‐insulated power apparatus such as GIS. However, the signal of PD occurring in SF₆ gas is very weak and susceptible to external noise in air. Moreover, because of the complicated mechanism of PD, the radiation property of electromagnetic waves from PD has not as yet been clarified. Therefore, it is hard to distinguish the PD signal in SF₆ gas from external noise. From the above points of view, we have been investigating the radiation mechanism of electromagnetic waves from PD. We measured the polarization characteristics of electromagnetic waves radiated from PD in comparison with those of half‐wave dipole antennas. The polarization characteristics of PD were explained by the theory of half‐wave dipole antenna, rather than that of an infinitesimal dipole antenna. Moreover, we compared the power spectrum for PD measured using a biconical antenna with that received from the half‐wave dipole antenna or infinitesimal dipole. It was found that the power spectrum for PD also corresponded to that for the half‐wave dipole antenna with a length of 50 cm. © 1999 Scripta Technica, Electr Eng Jpn, 126(4): 40–47, 1999     

Proposal for a benchmark model of a laminated iron core and a large‐scale and highly accurate magnetic analysis

This paper describes a benchmark model proposed for the clarification of the characteristic of various methods for modeling the laminated iron core. In order to obtain a reference solution of the benchmark model, a large‐scale nonlinear magnetostatic field analysis with a mesh fine enough to represent the microscopic structure of the laminated iron core is carried out by using the hybrid finite element–boundary element (FE‐BE) method combined with the fast multipole method (FMM) based on diagonal forms for translation operators. The computational costs and accuracy of two kinds of homogenization methods are discussed, comparing them with the reference solution. As a consequence, it is verified that the homogenization methods can analyze magnetic fields in laminated iron core within acceptable computational costs. © 2009 Wiley Periodicals, Inc. Electr Eng Jpn, 170(1): 26–35, 2010; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20809     

Motion and size estimation of a free moving metallic particle in GIS based on propagation properties of acoustic waves

We have investigated the propagation properties of Lamb waves and motion characteristic of free moving metallic particle in a gas‐insulated switchgear (GIS) tank to diagnose the insulation performance of GIS. We have proposed a new identification technique for defect location in GIS based on the time–frequency analysis of the Lamb waves using the Wavelet Transform. In this paper, we measured the acoustic signals excited by a metallic particle colliding with the tank sheath. Furthermore, we measured the moving particles under a high electric field in GIS using a high‐speed video camera. As a result, we examined the relationship between maximum lifting height and the flight time during subsequent impacts of a moving particle. Moreover, we estimated particle size based on the propagation properties of Lamb waves. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(1): 26–33, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20023     

A 300‐mA load CMOS low‐dropout regulator without an external capacitor for SoC and embedded applications

This study proposes a 300‐mA external capacitor‐free low‐dropout (LDO) regulator for system‐on‐chip and embedded applications. To achieve a full‐load range from 0 to 300 mA, a two‐scheme (a light‐load case and a heavy‐load case) operation LDO regulator with a novel control circuit is proposed. In the light‐load case (0–0.5 mA), only one P‐type metal–oxide–semiconductor input‐pair amplifier with a 10‐pF on‐chip capacitor is used to obtain a load current as low as 0. In the heavy‐load case (0.5 to 300 mA), both P‐type metal–oxide–semiconductor and N‐type metal–oxide–semiconductor differential input‐pair amplifiers with an assistant push‐pull stage are utilized to improve the stability of the LDO regulator and achieve a high slew rate and fast‐transient response. Measurements show an output voltage of 3.3 V and a full output load range from 0 to 300 mA. A line regulation of 1.66 mV/V and a load regulation of 0.0334 mV/mA are achieved. The measured power‐supply rejection ratio at 1 kHz is −65 dB, and the measured output noise is only 34 μV. The total active chip size is approximately 0.4 mm² with a standard 0.5 μm complementary metal–oxide–semiconductor process. Copyright © 2017 John Wiley & Sons, Ltd.     

Numerical characterization of nonlinear oscillatory waves in a composite right‐ and left‐handed traveling‐wave field‐effect transistor

A specialized type of traveling‐wave field‐effect transistor, the gate and drain lines of which have composite right‐ and left‐handed structures, is considered as the platform to support nonlinear oscillatory waves. The cubic–quintic complex Ginzburg–Landau equation is obtained by application of the reductive perturbation method, by which we quantify the homogeneous oscillations including the property of the Andronov–Hopf bifurcation point, oscillation frequency, and amplitude. Several numerical calculations follow to validate the Ginzburg–Landau equation‐based analysis. Finally, the dynamics of numerically obtained stationary flat‐top pulses are discussed. Copyright © 2016 John Wiley & Sons, Ltd.     

Numerical study of electromagnetic wave propagation through layered structures with chiral media

In this paper, the characteristics of layered structures (photonic or electromagnetic bandgaps), including chiral media, are studied by means of two different numerical methods, one in the time domain (finite differences in the time domain, FDTD) and the other in the frequency domain (coupled‐mode method, CMM). The results (reflection and transmission coefficients for a plane wave normally incident over a layered structure) obtained by means of both well different techniques are practically identical. Copyright © 2009 John Wiley & Sons, Ltd.     

Experimental verification of a dynamic voltage restorer capable of significantly reducing energy‐storage element requirements

This paper deals with a dynamic voltage restorer (DVR) characterized by installing the shunt converter at the load side. The DVR can compensate for the load voltage when a voltage sag appears in the supply voltage. An existing DVR requires a large capacitor bank or other energy‐storage elements such as double‐layer capacitors or batteries. The DVR presented in this paper requires only a small DC capacitor intended for smoothing the DC‐link voltage. Moreover, three control methods for the series converter are compared and discussed to reduce the series‐converter rating, paying attention to the zero‐sequence voltages included in the supply voltage and the compensating voltage. Experimental results obtained from a 200‐V, 5‐kW laboratory system are shown to verify the viability of the system configuration and the control methods. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(3): 73–82, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20460     

An integrated controller for high‐frequency LCLC resonant inverter with phase‐shifted control and frequency regulation

High‐frequency alternating current has an extensive application as a result of outstanding advantages. The aim of the study is to develop a high‐frequency power source to feed the auxiliary loads of vehicle application such as electric fans, blower motors, and lighting. A feasible implementation of high‐frequency power source is examined by a full‐bridge LCLC resonant inverter. The corresponding control scheme is proposed for the fourth‐order resonant inverter to confront the control challenges of low output harmonics and dynamic nonlinear load. Firstly, an analysis parameter S _r is defined to address the possible impacts of the varying operational frequency to output THD and ZVS features. Secondly, an integrated control scheme is presented to implement pulse‐width control at heavy load and frequency regulation at light load. Lastly, an experimental prototype is accomplished with the peak voltage of 35 V and the output power of 120 W. The accordance of experimental results and theoretical analysis testifies that the proposed control scheme can achieve the low harmonics and high conversion efficiency over a wide scope of operational conditions. Copyright © 2016 John Wiley & Sons, Ltd.     

Fast‐transient DC‐DC converter using a high‐performance error amplifier with a rapid output‐voltage control technique

This letter presents a method for improving the transient response of DC‐DC converters. The proposed technique replaces the conventional error amplifier with a combination of two different amplifiers to achieve a high loop gain and high slew rate. In addition, a rapid output‐voltage control circuit is employed to further reduce the recovery time. The proposed technique was applied to a four‐phase buck converter, and the chip was implemented using a 0.18‐μm CMOS process. The switching frequency of each phase was set at 2 MHz. Using a supply voltage of 2.7–5.5 V and an output voltage of 0.6–1.5 V, the regulator provided up to 2‐A load current with maximum measured recovery time of only 6.2 and 6.5 μs for increasing and decreasing load current, respectively. Copyright © 2017 John Wiley & Sons, Ltd.