• Title/Summary/Keyword: 2 phase pulse

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5-GHz Delay-Locked Loop Using Relative Comparison Quadrature Phase Detector

  • Wang, Sung-Ho;Kim, Jung-Tae;Hur, Chang-Wu
    • Journal of information and communication convergence engineering
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    • v.2 no.2
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    • pp.102-105
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    • 2004
  • A Quadrature phase detector for high-speed delay-locked loop is introduced. The proposed Quadrature phase detector is composed of two nor gates and it determines if the phase difference of two input clocks is 90 degrees or not. The delay locked loop circuit including the Quadrature phase detector is fabricated in a 0.18 um Standard CMOS process and it operates at 5 GHz frequency. The phase error of the delay-locked loop is maximum 2 degrees and the circuits are robust with voltage, temperature variations.

The power regulation of a High-Frequency Induction Heating System with time variance load using a neural fuzzy controller (뉴로퍼지 제어기를 이용한 고주파 유도 가열기의 시변부하에 대한 정전력 제어)

  • 장종승;김승철;임영도
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.2 no.2
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    • pp.223-230
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    • 1998
  • This paper describes a phase-shift pulse-width modulation and pulse-frequency modulation series resonant high-frequency inverter using IGBT(Insulated-Gated Bipolar Transistor) for the power control of high-frequency induction heating using neuro-fuzzy, which is practically applied for 20KHz~500KHz induction-heating and melting power supply in industrial fields. The adaptive frequency tracking based phase-shifting PWM(Pulse-Width Modulation) regulation scheme is presented in order to minimize switching losses. The trially-produced breadboards using IGBT are successfully demonstrated and discussed.

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Novel Two-Phase RPWM Technique for Three-Phase Induction Motor Drive (3상 유도전동기 구동을 위한 새로운 2상 RPWM기법)

  • Lee Hyo-Sang;Kim Nam-Joon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.9 no.5
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    • pp.430-437
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    • 2004
  • This thesis proposes novel SRP-PWM(Separately Random Pulse Position PWM) techniques and novel two-phase switching pattern applied to four-switch inverter, having various advantages such as operation time decrease that is required for decrease of switching damage, easy of implementation and inverter control at high frequency switching. In this thesis, we wish to confirm that SRP-PWM techniques disperse harmonic spectrum of inverter output current evenly into wide frequency area, that is, side-band of specification frequency. And we confirm the harmonic reduction effect of proposed techniques. Therefore, we will achieve an experiment by IGBT inverter using DSP and will verify the validity of proposed techniques compared with simulation results that use MATLAB/SIMULINK.

Design of a Clock and Data Recovery Circuit Using the Multi-point Phase Detector (다중점 위상검출기를 이용한 클럭 및 데이터 복원회로 설계)

  • Yoo, Sun-Geon;Kim, Seok-Man;Kim, Doo-Hwan;Cho, Kyoung-Rok
    • The Journal of the Korea Contents Association
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    • v.10 no.2
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    • pp.72-80
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    • 2010
  • The 1Gbps clock and data recovery (CDR) circuit using the proposed multi-point phase detector (PD) is presented. The proposed phase detector generates up/down signals comparing 3-point that is data transition point and clock rising/falling edge. The conventional PD uses the pulse width modulation (PWM) that controls the voltage controlled oscillator (VCO) using the width of a pulse period's multiple. However, the proposed PD uses the pulse number modulation (PNM) that regulates the VCO with the number of half clock cycle pulse. Therefore the proposed PD can controls VCO preciously and reduces the jitter. The CDR circuit is tested using 1Gbps $2^{31}-1$ pseudo random bit sequence (PRBS) input data. The designed CDR circuit shows that is capable of recovering clock and data at rates of 1Gbps. The recovered clock jitter is 7.36ps at 1GHz and the total power consumption is about 12mW. The proposed circuit is implemented using a 0.18um CMOS process under 1.8V supply.

A Sensorless Speed Control of 2-Phase Asymmetric SRM with Parameter Compensator (파라미터 보상기를 가지는 비대칭 SRM의 센서리스 속도제어)

  • Lim, Geun-Min;Ahn, Jin-Woo;Lee, Dong-Hee
    • The Transactions of the Korean Institute of Power Electronics
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    • v.17 no.3
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    • pp.238-245
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    • 2012
  • This paper presents a sensorless speed control of a 2-phase switch reluctance motor(SRM). The proposed sensorless control scheme is based on the slide mode observer with parameter compensator to improve the estimation performance. In the stand still position, the initial rotor position is determined by pulse current responses of each phase windings and the current difference. In order to determine an accurate initial rotor position, the two initial rotor positions are estimated by the difference of the pulse currents. From the stand still to the operating region, a simple open loop control which determines the commutation sequence by the pulse current of the unexcited phase winding is used. When the motor speed is reached to the sensorless control region, the estimated rotor position and speed by the slide mode observer are used to control the SRM. The flux calculator used in the slide mode observer is designed by phase voltage and the voltage drops in the phase resistance of the winding. The accuracy of the flux calculator is dependent on the phase resistance. For the continuous update of the phase resistance, current gradient at the inductance break point is used in this paper. The error of the estimated rotor position at the current gradient position is used to update the phase resistance to improve the sensorless scheme. The proposed sensorless speed control scheme is verified with a practical compressor used in home appliances. And the results show the effectiveness of the proposed control scheme.

Analysis of the Influence of Mutual Relation of Optical Pulse Frequency Chirp and Kerr Effect on the Mid-Span Spectral Inversion Methods for the Long-Haul Optical Transmission (광 펄스 주파수 첩과 Kerr 효과의 상호 관계가 장거리 광 전송을 위한 MSSI 보상 기법에 미치는 영향 분석)

  • 이성렬;이윤현
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.9
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    • pp.898-906
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    • 2002
  • In this paper, we investigated the improvement degree of transmission distance of the various initial frequency chirped optical pulse with 5 dBm initial power dependence on the various bit rate and fiber dispersion coefficient, when MSSI(Mid-Span Spectral Inversion) with the optimal pump power condition is adopted for the compensation method for optical pulse distortion. And we analyzed the influence of mutual relation of optical pulse frequency chirp and Kerr effect on the MSSI methods for the long-haul optical transmission through the computer simulation. We found that the compensation degree of distorted optical pulse varies as a consequence of the variation of combined phase modulation of self phase modulation(Kerr effect) and initial frequency chirp parameter dependence on the fiber dispersion coefficient. And we found that, if the transmission bit rate is increased k times, the dispersion coefficient value of dispersion shift fiber is decreased $2^k$ times so as to be almost the same performance of the transmission system with k times lower bit rate.

Temporal characterization of femtosecond laser pulses using spectral phase interferometry for direct electric-field reconstuction (주파수 위상 간섭계를 이용한 펨토초 레이저 펄스의 시간적 특성연구)

  • 강용훈;홍경한;남창희
    • Korean Journal of Optics and Photonics
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    • v.12 no.3
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    • pp.219-224
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    • 2001
  • Spectral phase interferometry for direct electric-field reconstruction (SPIDER) was fabricated and used to characterize pulses from a Ti:sapphire oscillator. In the SPIDER apparatus, two replicas of the input pulse were generated with a time delay of 200 fs and were upconverted by use of sum-frequency generation with a strongly chirped pulse using a 8-cm-long SFIO glass block at a 30-11m-thick type II BBO (p-BaBz04) crystal. The resulting interferogram was recorded with a UV-enhanced CCD array in the spectrometer. The spectral phase was retrieved by SPIDER algorithm in combination with independently measured pulse spectrum and the corresponding temporal intensity profile was reconstructed with a duration of 19 fs. As an independent cross-check of the accuracy of the method, we compared the interferometric autocorrelation (lAC) signal calculated from the SPIDER data with a separately measured lAC. The conventional, but unjustified, method of fitting a sechz pulse to the autocorrelation deceivingly yielded a pulse duration of 15 fs. This systematic underestimation of the pulse duration affirms the need for a complete characterization method. From the consideration in this paper, we concluded that the SPIDER could provide an accurate characterization of femtosecond pulses. ulses.

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The Study of Phase-change with Temperature and Electric field in Chalcogenide Thin Film

  • Yang, Sung-Jun;Shin, Kyung;Park, Jung-Il;Lee, Ki-Nam;Chung, Hong-Bay
    • Transactions on Electrical and Electronic Materials
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    • v.4 no.5
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    • pp.24-27
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    • 2003
  • We have been investigated phase-change with temperature and electric field in chalcogenide Ge$_2$Sb$_2$Te$\sub$5/ thin film. T$\sub$c/(crystallization temperature) is confirmed by measuring the resistance with the varying temperature on the hotplate. We have measured I-V characteristics with Ge$_2$Sb$_2$Te$\sub$5/ chalcogenide thin film. It is compared with I-V characteristics after impress the variable pulse. The pulse has variable height and duration.

Two-Dimensional Analysis Model of a Pulse Tube (맥동관의 2차원 해석모델)

  • 백상호;정은수
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 1999.02a
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    • pp.157-160
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    • 1999
  • Enthalpy transport in a pulse tube was investigated by two-dimensional analysis of mass, momentum and energy equations of the gas as well as energy conservation of the tube wall. The mean temperature of the gas and the tube wall was obtained directly by assuming that the outer surface of a pulse tube is adiabatic. Effects of operating frequency, tube wall thickness, velocity ratio and velocity phase angle between both ends of a pulse tube on net enthalpy flow were shown.

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Dual-phase-lag model on microstretch thermoelastic medium with diffusion under the influence of gravity and laser pulse

  • Othman, Mohamed I.A.;Abd-Elaziz, Elsayed M.;Mohamed, Ibrahim E.A.
    • Structural Engineering and Mechanics
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    • v.75 no.2
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    • pp.133-144
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    • 2020
  • This investigation is to study the effect of gravitational field and diffusion on a microstretch thermoelastic medium heating by a non-Gaussian laser beam. The problem was studied in the context of the dual-phase-lag model. The normal mode analysis is used to solve the problem to obtain the exact expressions for the non-dimensional displacement components, the micro-rotation, the stresses, and the temperature distribution. The effect of time parameter, heat flux parameter and gravity response of three theories of thermoelasticity i.e. dual-phase-lag model (DPL), Lord and Shulman theory (L-S) and coupled theory (CT) on these quantities have been depicted graphically for a particular model.