• Title/Summary/Keyword: phase comparison

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A Design of Simple and Precision Direction Finder with a Combination of an Amplitude Measurement and Phase Measurement

  • Lim Joong-Soo
    • International Journal of Contents
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    • v.1 no.2
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    • pp.35-38
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    • 2005
  • This paper describes a design of simple and precision direction finder that can be adapted to shipboard or mobile vehicles used for Electronic support measure, ELINT and radio signal monitoring systems. The direction finding technology has improved with monolithic integrated circuit, linear array antennas, and interferometer. Interferometer uses the phase-comparison principle and has a good direction finding accuracy but it has an ambiguity problem. We suggest a simple ambiguity solver using phase-comparison technology with amplitude-comparison principle. The direction finding device that has been designed by the suggested method has 0.7 degree RMS error in azimuth angle and 0.6 degree RMS error in elevation angle in 0.5 - 2.0 GHz.

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Comparison of Current Control Method for Single-phase PFC converter with 1-switch Voltage Doubler Strategy (단일 스위치 배전압 방식의 단상 PFC 컨버터의 전류 제어기법 비교)

  • Ku, Dae-Kwan;Ji, Jun-Keun;Cha, Guee-Soo;Lim, Seung-Beom;Hong, Soon-Chan
    • The Transactions of the Korean Institute of Power Electronics
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    • v.17 no.1
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    • pp.1-7
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    • 2012
  • This paper describes the performance comparison results for current controller of a single-phase PFC converter with 1-switch voltage doubler strategy for single-phase double-conversion UPS(Uninterruptible Power Supply). A single-phase PFC converter with 1-switch voltage doubler strategy needs a diode bridge and one bidirectional active switch. Thus it is possible to reduce the material cost. However, the study results of current controller design and comparison of current control method has not been known after the converter circuit was proposed. For the performance comparison of current control, single-phase 3 kVA double-conversion UPS was tested. The performance of PI and PR current controller is experimentally confirmed with followings - input current reference tracking, input power factor correction and input current THD suppression.

A Performance Analysis of Phase Comparison Monopulse Algorithm for Antenna Spacing and Antenna Array (안테나 간격 및 배열에 따른 위상 비교 모노펄스 알고리즘의 성능 분석)

  • Sim, Heon-Kyo;Jung, Min-A;Kim, Seong-Cheol
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.7
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    • pp.1413-1419
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    • 2015
  • Monopulse RADAR is the radar which detects the range of the target using a single transmitted signal. In this paper, using 9.41GHz X-band radar, the research for the phase comparison monopulse algorithm used in the marine environment is conducted. In addition, by applying the phase comparison monopulse algorithm, we calculate the RMSE for the various antenna spacings and the positions of the target. Based on that result, we compare the performance of the phase comparison monopulse algorithm in the uniform linear array with that in the non-uniform linear array. Finally, the differences in performance among the MUSIC algorithm, Bartlett method and the proposed phase comparison monopulse algorithm are analyzed.

Accuracy Improvement of the Estimated Angle Using Phase Averaging in Phase-Comparison Monopulse Algorithm (위상 비교 모노 펄스 알고리즘에서 위상평균법을 이용한 추정 각도 정확도 향상)

  • Cho, Byung-Lae;Lee, Jung-Soo;Lee, Jong-Min;Sun, Sun-Gu
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.10
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    • pp.1212-1215
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    • 2012
  • This study describes the accuracy improvement of the estimated angle using phase averaging in phase-comparison monopulse algorithm. In addition, to compensate the time-delay due to the phase averaging, we propose the time-delay compensation algorithm which uses the derivative of the estimated angle. These derivative is calculated by the curve fitting method. Using the real radar interferometer, we have verified that the phase averaging and time-delay compensation algorithms are effective in real-time signal processing application.

Performance Comparison of Single-Phase PLL Algorithms Using Virtual 2-Phase Strategy (가상 2상 방식을 사용한 단상 PLL 알고리즘의 성능 비교)

  • Lee, Yong-Seok;Ji, Jun-Keun
    • Proceedings of the KIEE Conference
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    • 2006.10d
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    • pp.226-228
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    • 2006
  • This paper presents a comparative study of single-phase PLL algorithms using virtual 2-phase strategy. Simulation and experimental results, including operation of the PLL structures introduced in reference papers, are presented to allow a performance comparison of the PLL algorithms.

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Data Convergence of circular Array Correlative Interferometer Direction Finding with 7-Antenna (7-안테나로 구성된 원형배열 상관형 위상비교 방향탐지의 데이터 융합)

  • Lim, Joong-Soo
    • Journal of the Korea Convergence Society
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    • v.8 no.1
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    • pp.1-6
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    • 2017
  • In this paper, we propose a new method for a correlative phase comparison direction finding(DF) which detects the arrival direction of radio waves by data fusing the calculated phase difference and the measured phase difference between the antennas when the radio waves are incident on the circular array antenna composed of 7 antennas respectively. The correlation type phase comparison method uses a uniform circular array(UCA) and a linear array method. The phase difference data calculated formally and the phase difference data measured in the test environment are fused with a correlation function, therefore, it is superior to the currently used phase comparison direction detection method. When the signal-to-noise ratio (SNR) of the received signal is 20dB and the inter-antenna distance to the wavelength of the received signal($L/{\lambda}$) is 0.5, the accuracy of the correlative DF is $1.7^{\circ}$ while measurement phase comparison's is larger than $2.5^{\circ}$, It can be used for electromagnetic signal monitoring and military direction detection.

Analysis of Direction Finding Accuracy for Amplitude-Phase Comparison and Correlative Interferometer Method (진폭-위상 복합비교 기법과 상관형 위상비교 기법의 방향탐지 정확도 분석)

  • Lim, Joong-Soo;Chae, Gyoo-Soo
    • Journal of Digital Convergence
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    • v.14 no.1
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    • pp.195-201
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    • 2016
  • In this paper, we present the direction finding accuracy of correlative interferometer method and amplitude-phase comparison method. Spiral antennas are used for amplitude-phase comparison method and blade antennas are used for correlative interferometer method. Those are made for uniform circular array (UCA) direction finding antenna systems. We simulate the accuracy of azimuth angle with 3 antennas UCA when SNR is 20 dB and baseline is 0.5 wave length. Correlative interferometer method has better accuracy than amplitude-phase comparison method.

Quantitative Analysis and Comparisons between In-Phase Control and Energy-Optimized Control for Series Power Quality Controllers

  • Xinming, Hunag;Jinjun, Liu;Hui, Zhang
    • Journal of Power Electronics
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    • v.9 no.4
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    • pp.553-566
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    • 2009
  • In-phase control and energy-optimized control are the two major control strategies proposed for series power quality controllers (SPQC). However quantitative analysis and comparison between these two control strategies is quite limited in previous publications. In this paper, an extensive quantitative analysis is carried out on these two control strategies through phasor diagram approach, and a detailed quantitative comparison is conducted accordingly. The load current is used as the reference phasor, and this leads to a simpler and clearer phasor diagram for the quantitative relationship. Subsequently detailed analysis of SPQC using in-phase control and energy-optimized control are provided respectively, under different modes both for under voltage/voltage sag and for over voltage/voltage swell. The closed form analytic expressions and the curves describing SPQC compensation characteristics are obtained. The detailed system power flow is figured out for each mode, and the detailed quantitative comparison between the two control strategies is then carried out. The comparison covers several aspects of SPQC, such as required compensating voltage magnitude, required capacity of energy storage component, and maximal ride-through time. In the end, computer simulation and prototype experimental results are shown to verify the validity of all the analysis and the result of the comparison.

Performance Comparison to Solve Angle Ambiguity Needed to Angle of Arrival Estimation in 2D Radar Interferometer (2차원 레이다 간섭계에서 각도 추정 알고리즘의 각도 모호성 해소 성능 비교)

  • Cho, Byung-Lae;Lee, Jung-Soo;Lee, Jong-Min;Sun, Sun-Gu
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.3
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    • pp.410-413
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    • 2012
  • This study describes the performance comparison to solve angle ambiguity needed to angle of arrival estimation in 2D radiometer. There are three algorithms to solve its ambiguity such as phase-comparison monopulse method, digital beam-forming method and least square error of the phase difference in 2D radar interferometer. To estimate two direction angles, phase-comparison monopulse method is sequentially applied to azimuth and elevation direction. To analyze the performance of these methods, probability of solving angle ambiguity and execution time have been chosen as performance indexes. Through the Monte Carlo simulation, we have verified that phase-comparison monopulse method is most effective in real-time signal processing application.

Comparison of phase noise characteristic of Quadrature Voltage Controlled Oscillator (직교신호 발생 전압제어 발진기의 위상 잡음 특성비교)

  • Cho, Il-Hyun;Lee, Moon-Que;Kim, Hyeong-Seok
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.2333-2335
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    • 2005
  • Various CMOS quadrature-voltage-controlled oscillators(QVCOs) are designed and fabricated for the comparison of the phase noise. The core VCO is composed of two Colpitts oscillators which are cross-coupled with PMOS pair. For the comparison of phase noise with the proposed scheme, the conventional LC VCO followed by the frequency-divide-by-two is designed. The simulation result demonstrate that the proposed scheme shows better phase noise performance by 6dB than that of a conventional scheme in which LC VCO is followed by the frequency-divide-by-two.

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