• Title/Summary/Keyword: Electrical Nonlinearity

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Degradation Characteristics Against Impulse Current Stress of ZPCCL-Based Varistors (ZPCCL계 바리스터의 충격전류 스트레스에 대한 노화 특성)

  • Park, Jong-Ah;Yoo, Dea-Hoon;Nahm, Choon-Woo;Seo, Hyung-Gwon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2005.07a
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    • pp.315-317
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    • 2005
  • The microstructure, electrical, and degradation characteristics against impulse current of ZPCCL-based varistors were investigated with various sintering temperature in the range of $1240\sim1300^{\circ}C$. The densification of varistors was improved, but the nonlinearity was deteriorated with increase of sintering temperature. The varistors sintered at $1250^{\circ}C$ and $1260^{\circ}C$ exhibited high stability against surge stress. On the whole, the variation of characteristics of varistor for surge stress was increased in order of varistor voltage$\rightarrow$nonlinear exponent$\rightarrow$dissipation factor$\rightarrow$leakage current.

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Electrical Properties and Stability of ZPCCD-Based Varistors with Sintering Time (소결시간에 따른 ZPCCD계 바리스터의 전기적 특성 및 안정성)

  • Nahm, Choon-Woo;Park, Jong-Ah;Yoo, Dea-Hoon;Suh, Hyoung-Kwon
    • Journal of the Korean Ceramic Society
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    • v.42 no.7 s.278
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    • pp.490-496
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    • 2005
  • The electrical properties and stability of the varistors composed of ZnO-Pr$_{6}$O$_{11}$-CoO-Cr$_{2}$O$_{3}$-Dy$_{2}$O$_{3}$ system were investigated with sintering time in the range of 1$\~$3 h at 1350$^{\circ}C$ . As the sintering time was increased, the varistor voltage and leakage current increased, but the nonlinear exponent decreased. The varistors sintered for 1 h exhibited excellent nonlinearity, with a nonlinear exponent of 55.3 and a leakage current of 0.1 $\mu$A, whereas presented relatively low stability. The varistors sintered for 2 h exhibited not only high nonlinear exponent of 46.3, low leakage current of 0.3 $\mu$A, low dielectric dissipation factor of 0.0431, but also the highest stability, in which the variation rates of varistor voltage, nonlinear exponent, leakage current, dielectric constant, and dielectric dissipation factor were -3.0$\%$, -4.1$\%$, +3056.2$\%$, +5.1$\%$, and -12.5$\%$, respectively, after DC accelerated aging stress state of 0.95 V$_{1ma}$/150$^{\circ}C$/24 h. On the whole, the nonlinearity and stability of these varistors are greatly affected by the sintering time.

Nonlinearlity Compensation of Heterodyne laser interferometer based on LMS (LMS를 이용한 헤테로다인 레이저 간섭계 비선형성 보정)

  • Jeong, Pil-Joong;Lee, Woo-Ram;You, Kwan-Ho
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.283-284
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    • 2007
  • In this paper we introduce a compensation of nonlinearity Heterodyne laser interferometer. The Laser Interferometer is used for length measurement in various industries. However, it has nonlinearity error caused by the imperfect optical equipment. This acts as an obstacle in the measurement improvement. We propose an adaptive error compensation using least mean square(LMS) to improve precision.

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PMD Effect on the Clock-based Optimum Dispersion Compensation Monitoring Technique

  • Kim, Sung-Man
    • Journal of the Optical Society of Korea
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    • v.13 no.1
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    • pp.112-115
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    • 2009
  • We investigate the effect of polarization-mode dispersion (PMD) on the optimum dispersion compensation (ODC) monitoring and nonlinear penalty in optical transmission systems. We report that PMD may reduce the fiber nonlinearity. We also report that the monitoring error of the clock-based ODC monitoring technique decreases after the first-order PMD compensation. A simple explanation of this phenomenon is shown.

A Study on Single-bit Feedback Multi-bit Sigma Delta A/D converter for improving nonlinearity

  • Kim, Hwa-Young;Ryu, Jang-Woo;Jung, Min-Chul;Sung, Man-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.11a
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    • pp.57-60
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    • 2004
  • This paper presents multibit Sigma-Delta ADC using Leslie-Singh Structure to Improve nonlinearity of feedback loop. 4-bit flash ADC for multibit Quantization in Sigma Delta modulator offers the following advantages such as lower quantization noise, more accurate white-noise level and more stability over single quantization. For the feedback paths consisting of DAC, the DAC element should have a high matching requirement in order to maintain the linearity performance which can be obtained by the modulator with a multibit quantizer. Thus a Sigma-Delta ADC usually adds the dynamic element matching digital circuit within feedback loop. It occurs complexity of Sigma-Delta Circuit and increase of power dissipation. In this paper using the Leslie-Singh Structure for improving nonliearity of ADC. This structure operate at low oversampling ratio but is difficult to achieve high resolution. So in this paper propose improving loop filter for single-bit feedback multi-bit quantization Sigma-Delta ADC. It obtained 94.3dB signal to noise ratio over 615kHz bandwidth, and 62mW power dissipation at a sampling frequency of 19.6MHz. This Sigma Delta ADC is fabricated in 0.25um CMOS technology with 2.5V supply voltage.

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Output Feedback Control of a Class of Nonlinear Systems with Sensor Noise Via Matrix Inequality Approach (행렬 부등식 접근법을 이용한 센서 노이즈 비선형 시스템의 출력궤환 제어)

  • Koo, Min-Sung;Choi, Ho-Lim
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.8
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    • pp.748-752
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    • 2015
  • We present an output feedback controller for a class of nonlinear systems with uncertain nonlinearity and sensor noise. The sensor noise has both a finite constant component and a time-varying component such that its integral function is finite. The new design and analysis method is based on the matrix inequality approach. With our proposed controller, the states and output can be ultimately bounded even though the structure of nonlinearity is more general than that in the existing results.

Nonlinearity Error Compensation in Heterodyne Laser Interferometer using WLS Method (WLS를 이용한 헤테로다인 레이저 간섭계에서의 비선형 오차 보정)

  • Cha, Hyung-Seok;Lee, Woo-Ram;You, Kwan-Ho
    • Proceedings of the KIEE Conference
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    • 2007.10a
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    • pp.271-272
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    • 2007
  • In heterodyne laser interferometer, we use a phase difference between two beams to calculate target's length. However, there exist an nonlinearity error when measuring length in nanoscale. It is caused from frequency-mixed problem of two polarized beams, called cross talks. This fact limits the usefulness of an laser interferometer. To compensate the error, we propose a WLS(weighted least square) algorithm, which will reduce nonlinearity error and make a better optimization in heterodyne laser interferometer.

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On the Standard Composition of ZnO Varistor having Higher Nonlinearity and the Effect of Additives (높은 비직선성을 갖는 ZnO 바리스터의 기본조성 결정과 첨가물에 의한 영향)

  • Chung, Ju-Hyuck;Jin, Hee-Chang;Mah, Jae-Pyung;Paek, Su-Hyon
    • Proceedings of the KIEE Conference
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    • 1987.07a
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    • pp.565-568
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    • 1987
  • In order to determine the standard composition of ZnO varistor with higher nonlinearity, various contents of $MnO_2$, $Co_2O_3$ were added to ZnO-1.0m/o $Bi_2O_3$ system. Also, samples that contained small amount of Sb, Si-oxides in standard composition determined before were fabricated. As a result, the standard composition of higher nonlinearity-oriented ZnO varistor was shown as ZnO-1.0 m/o $Bi_2O_3$-1.0m/o $MnO_2$-1.0m/o $Co_2O_3$ and $Sb_2O_3$ largely enhanced nonlinear exponent and nonlinear resistance, hut SiO largely enhanced nonlinear exponent only.

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Electrical Properties and Stability of ZPCE Based Varistors (ZPCE계 바리스터의 전기적 성질 및 안정성)

  • Nahm, Choon-Woo;Yoon, Han-Soo;Ryu, Jung-Sun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.05b
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    • pp.190-195
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    • 2000
  • The electrical properties and stability of ZPCE varistors consisted of $ZnO-Pr_6O_{11}-CoO-Er_2O_3$ ceramics were investigated. $ZnO-Pr_6O_{11}-CoO-Er_2O_3$ based ceramics were sintered at $1300^{\circ}C$ and $1350^{\circ}C$, respectively, without and with 0.5 mol% $Er_2O_3$. The varistors sintered at $1300^{\circ}C$ exhibited a better nonlinearity than that $1350^{\circ}C$. The varistors with $Er_2O_3$ of 0.5 mol% exhibited a high nonlinear exponent of 52.8. However, they easily degraded due to the low density below 85% of TD. On the other hand, the varistors sintered at $1350^{\circ}C$ without $Er_2O_3$ exhibited an extremely poor nonlinearity, but the varistors with $Er_2O_3$ of 0.5 mol% exhibited a relatively good nonlinearity, which the nonlinear exponent is 34.8 and the leakage current is $7.4\;{\mu}A$ Morever, they exhibited a very high stability, which the variation rate of varistor voltage, nonlinear exponent, and leakage current are -0.9%, -2.9%, and +2.7%, respectively, under the third stress $(0.80 V_{1mA}/90^{\circ}C/12h)$ + $(0.85 V_{1mA}/115^{\circ}C/12h)$ + $(0.90 V_{1mA}/120^{\circ}C/12h)$. Consequently, it was estimated that $ZnO-Pr_6O_{11}-CoO-Er_2O_3$ ceramics will be usefully applied to develop the advanced $Pr_6O_{11}$-based ZnO varistors.

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Microstructure and Electrical Properties of $Pr_6$$O_{11}$-Based ZnO Varistors Doped with $Nd_24$O_3$ ($Nd_24$O_3$가 첨가된 $Pr_6$$O_{11}$계 ZnO 바리스터의 미세구조 및 전기적 성질)

  • 남춘우;박춘현;윤한수
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.13 no.3
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    • pp.206-213
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    • 2000
  • The microstructure and electrical properties of Pr$_{6}$/O sub 11/-Based ZnO varistors with Nd$_2$O$_3$ was doped in the range of 0.0 to 2.0 mol% were investigated. Most of the added Nd$_2$O$_3$were segregated at the nodal points and grain boundaries and were found to form the Nd-rich phase. In addition the bulk intergranular layer at the grain boundaries and nodal points was consisted of Nd-rich phase and Pr-rich phase. the average grain size was decreased in the range of 7.8 to 5.6${\mu}{\textrm}{m}$ with increasing Nd$_{2}$/O sub 3/ additive content. The nonlinearity of ZnO varistors sintered at 130$0^{\circ}C$ was much more excellent than that at 135$0^{\circ}C$ ZnO varistors doped with 1.0mol% Nd$_{2}$/O sub 3/ exhibited the best nonlinearity. which is 65.2 in the nonlinear exponent and 4.5$\mu$A in the leakage current. Consequently. it is estimated that Pr$_{6}$/O sub 11/ -based ZnO varistors doped with 1.0 mol% Nd$_{2}$/O sub 3/ are to be sufficiently used as basic composition to fabricate good varistors in the future.ure.

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