• Title, Summary, Keyword: phase error

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Effect of Phase Error on 3-D Image Reconstruction in the Modified Triangular Interferometer (변형 삼각간섭계에서 위상오차가 3차원 복원영상에 미치는 영향에 관한 연구)

  • Kim, Soo-Gil
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.23 no.10
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    • pp.1-6
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    • 2009
  • We derive the phase error of hologram due to imperfection of a wave plate, the azimuth angle error of a wave plate, and the azimuth angle error of a linear polarizer. Also, we analyze the effect of phase error by the modified triangular interferometer in case of 3-D image reconstruction of hologram.

A Broadband Digital Step Attenuator with Low Phase Error and Low Insertion Loss in 0.18-${\mu}m$ SOI CMOS Technology

  • Cho, Moon-Kyu;Kim, Jeong-Geun;Baek, Donghyun
    • ETRI Journal
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    • v.35 no.4
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    • pp.638-643
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    • 2013
  • This paper presents a 5-bit digital step attenuator (DSA) using a commercial 0.18-${\mu}m$ silicon-on-insulator (SOI) process for the wideband phased array antenna. Both low insertion loss and low root mean square (RMS) phase error and amplitude error are achieved employing two attenuation topologies of the switched path attenuator and the switched T-type attenuator. The attenuation coverage of 31 dB with a least significant bit of 1 dB is achieved at DC to 20 GHz. The RMS phase error and amplitude error are less than $2.5^{\circ}$ and less than 0.5 dB, respectively. The measured insertion loss of the reference state is less than 5.5 dB at 10 GHz. The input return loss and output return loss are each less than 12 dB at DC to 20 GHz. The current consumption is nearly zero with a voltage supply of 1.8 V. The chip size is $0.93mm{\times}0.68mm$, including pads. To the best of the authors' knowledge, this is the first demonstration of a low phase error DC-to-20-GHz SOI DSA.

Analysis of Effect of Phase Error Sources of Polarization Components in Incoherent Triangular Holography

  • Kim, Soo-Gil
    • Journal of the Optical Society of Korea
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    • v.16 no.3
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    • pp.256-262
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    • 2012
  • We derive the point-spread function of the reconstructed image from a point-source complex hologram, which includes phase error caused by polarization components, in the longitudinal direction of the point-spread function and analyze the effect of the error sources of polarization components having influence on image reconstruction of a point-source complex hologram in incoherent triangular holography.

The Error Rate Evaluation for Differential Demodulation of 2-h Continuous Phase Modulation (차동 복조 2-h 연속 위성 변조의 오류 확률)

  • 윤동원;한영열
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.31A no.7
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    • pp.29-35
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    • 1994
  • The performance of continuous phase modulation signals is well known for the coherent demodulation. But the carrier recovery circuits of the coherent receiver have long acquisition time and the receiver experiences high error floors for fading channels. In this paper, we propose the differential demodulation of 2-h continuous phase modulation signals. The sets of modulation indices of 2-h phase codes adequate to the differential demodulation for differentially encoded input are obtained and the average bit error probability in Additive White Gaussian Noise environments is derived and analyzed.

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Interrelationship of phase-error variance and correlation coefficient in microwave imaging (마이크로웨이브 이미징에서 위상오차 분산과 코릴레이션 계수와의 상호관계)

  • 강봉순;장훈기
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.10
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    • pp.1-6
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    • 1997
  • This paper presents the theoretical derivaion relating and image correlationcoeffcient capable of assessing image quality, with phase-error variance in antenna aperture domain. We show that when the phase-error variance of a range bin selected as an adaptive beamformer is known, the quality of the reconstructed image is predictable and moreover, the resultant correlation coeffcient is obviously greater than the derive dlower boudn. To support the derivation, real data are used for image formation where the dominant scatterer algorithm (DSA) is applied for phase compensations.

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A Study on Effects of Offset Error during Phase Angle Detection in Grid-tied Single-phase Inverters based on SRF-PLL (SRF-PLL을 이용한 계통연계형 단상 인버터의 전원 위상각 검출시 옵셋 오차 영향에 관한 연구)

  • Kwon, Young;Seong, Ui-Seok;Hwang, Seon-Hwan
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.29 no.10
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    • pp.73-82
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    • 2015
  • This paper proposes an ripple reduction algorithm and analyzes the effects of offset and scale errors generated by voltage sensor while measuring grid voltage in grid-tied single-phase inverters. Generally, the grid-connected inverter needs to detect the phase angle information by measuring grid voltage for synchronization, so that the single-phase inverter can be accurately driven based on estimated phase angle information. However, offset and scale errors are inevitably generated owing to the non-linear characteristics of voltage sensor and these errors affect that the phase angle includes 1st harmonic component under using SRF-PLL(Synchronous Reference Frame - Phase Locked Loop) system for detecting grid phase angle. Also, the performance of the overall system is degraded from the distorted phase angle including the specific harmonic component. As a result, in this paper, offset and scale error due to the voltage sensor in single-phase grid connected inverter under SRF-PLL is analyzed in detail and proportional resonant controller is used to reduce the ripples caused by the offset error. Especially, the integrator output of PI(Proportional Integral) controller in SRF-PLL is selected as an input signal of the proportional resonant controller. Simulation and experiment are performed to verify the effectiveness of the proposed algorithm.

An Analysis of Performance Error of Roundness Measuring Instrument -by phase different method- (眞圓度 測定器의 誤差特性에 대한 解析 -위상차법-)

  • 한응교;허문석;박익근
    • Journal of the korean Society of Automotive Engineers
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    • v.10 no.3
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    • pp.31-37
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    • 1988
  • A phase different method to evaluate the instrument error of roundness measuring instrument and the form error of specimens for the calibration of the instrument is used. An instrument with a rotary table supported by an air bearing was calibrated by using the standard balls as a standard. The calibration was carried out repeatedly by setting the same ball in 12 phase angles(per 30.deg.) on the table and by recording their roundness errors with a magnification of 100,000 times. As a result of data analysis of all the observations, readout at each of 144 orientations(per 2.5.deg.) from recorded data file, the error of performance of the instrument and the specimens are separated. In the particular instrument used in the present experiment, the error of the instrument was determined with the accuracy of 0.0164 (.mu.m) and the form error of the specimens was determined with the accuracy of 0.0264,0.0172(.mu.m), respectively. If the instrument was calibrated by using the above specimens, then the accuracy of the measurement of roundness error can be improved to about 0.017 (.mu.m).

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A novel phase error predictor for servo system in home-use VCRs (가정용 VCR의 서보 시스템을 위한 새로운 위상 오차 예측기)

  • 이상락;박정배;유지윤;박귀태;신영후
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.4
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    • pp.530-534
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    • 1996
  • A novel phase error predictor is proposed for servo system in home-use VCRs. The multirate system in VCRs is converted into a single period sampling system with faster sampling time by using the proposed novel phase error predictor. And the disturbances can be measured much faster. From the experimental results, we can see that the perfomance of the control system is improved greatly. The phase lock time of the proposed servo system is ten times faster than that of the conventional system.

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Finite Wordlength Recursive Sliding-DFT for Phase Measurement

  • Kim, Byoung-Il;Cho, Min-Kyu;Chang, Tae-Gyu
    • Journal of Electrical Engineering and Technology
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    • v.7 no.6
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    • pp.1014-1022
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    • 2012
  • This paper proposes a modified recursive sliding DFT to measure the phase of a single-tone. The modification is to provide a self error-cancelling mechanism so that it can significantly reduce the numerical error, which is generally introduced and accumulated when a recursive algorithm is implemented in finite wordlength arithmetic. The phase measurement error is analytically derived to suggest optimized distributions of quantization bits. The analytic derivation and the robustness of the algorithm are also verified by computer simulations. It shows that the maximum phase error of less than $5{\times}10^{-2}$ radian is obtained even when the algorithm is coarsely implemented with 4-bit wordlength twiddle factors.