• Title/Summary/Keyword: frequency detector

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Design of RF Power Detector Module with Switch for W-CDMA Optic Repeater (스위치를 이용한 W-CDMA 광중계기용 RF 전력 검출기 모듈의 설계)

  • Lee, Yun-Bok;Cho, Jung-Yong;Shin, Kyung-Sub;Lee, Yong-An;Lee, Hong-Min
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.389-393
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    • 2003
  • This paper describes the design of enhanced TSSI RF Power Detector which has wide dynamic range using switch and Log amp. This Power Detector consists of low and high gain loops, and they adaptively switched by output DC voltage which is proportioned to input power level. Because Power Detector needs to separate the channel, so architecture is heterodyne system having 70MHz intermediate frequency. This proposed RF Power Detector is settle to the satisfaction of Closed loop power control system for W-CDMA optic repeater, and the obtained dynamic range cover the higher than 50dB.

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A Study on the Improvement of Characteristics of Precharge PFD (Precharge형 PFD의 동작 특성 개선에 관한 연구)

  • Woo, Young-Shin;Kim, Du-Gon;Oh, Reum;Sung, Man-Young
    • Proceedings of the KIEE Conference
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    • 2000.07d
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    • pp.3088-3090
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    • 2000
  • In this paper, we introduce a charge pump PLL architecture which employs precharge phase frequency detector(PFD) and sequential PFD to achieve high frequency operation and fast acquisition. Operation frequency is increased by using precharge PFD when the phase difference is within -${\pi}\;{\sim}\;{\pi}$ and acquisition time is shortened by using sequential PFD and increased charge pump current when the phase difference is larger than |${\pi}$|. SO error detection range of proposed PLL structure is not limited to -${\pi}\;{\sim}\;{\pi}$. By virtue of this multi-phase frequency detector structure, the maximum operating frequency of 423MHz at 2.5V and faster acquisition were achieved by simulation.

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Optical frequency locked loop using quadricorrelator (Quadricorrelator 방식을 이용한 광주파수 잠김루프 제작)

  • 유강희;박창수;박진우
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.21 no.12
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    • pp.3286-3292
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    • 1996
  • An experimental results of optical requency locked loop with DFB semiconductor laser as VCO are presented. Using quadricorrelator as frequency difference detector and frequency off-set locking technique with 1GHz reference frequency, frequency locking range of 140MHz was achieved. This paper reports the design and realization details of the loop.

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Development of Microvibration Sensing Appratus using Photo Coupler (포토커플러를 이용한 미세 진동 측정장치)

  • 김호수;구경완;이명섭;김유배;이승권
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.798-801
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    • 2001
  • we have investigated a characteristic of a vibration displacement detector, which was made with a photocoupler. Output signals of the detector were dominant at 700Hz of the frequency of vibrator, and It was maximum, when the amplitude of input signal had been at 1.1V. The detector will be used in measuring the surface roughness of substrates.

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Detection of narrowly spaced tone signals using a nonlinear energy tracker (비선형 에너지 추적기를 이용한 근접된 톤 신호 검출)

  • 황성수;이용환
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.22 no.11
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    • pp.2470-2476
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    • 1997
  • We propose a simle scheme for detecting tone signals narrowly spaced in the frequency by employing a nonlinear device called Teager's energy tracker. When the input signal is a tone signal, the output of Teager's energy tracker is proportional to the energy and tone frequency of the input signal. When the envelope of the input tone is varying, this tracker can also track the energy of the envelope. By employing Teager's algorithm as a preprocessor, the detector for narrowly spaced tone signals can be implemented without the use of sharp notch filters. As an example, the proposed detector is applied to distinguishing ITU-T V.8 and V.25 tone signals. The detector perfodrmance is analyszed and is verified by computer simulation.

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Speed Signal Detector with Frequency 6-Multiplier used for the Railway Vehicles (철도차량용 6체배 주파수 속도신호발생장치)

  • Lee, Eul-Jae;Yoon, Yong-Ki;Jeong, Rag-Gyo;Choi, Kyu-Hyoung
    • Proceedings of the KIEE Conference
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    • 2003.07b
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    • pp.1315-1317
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    • 2003
  • In this paper, a hew ground speed signal detector used for railway vehicles is presented. A frequency 6-multiplier is designed to the proposed speed signal detector to achieve more precise ground speed from the slow analog signals made from mechanical tacho signal generator. The computer simulation is carried out to clarify its effectiveness.

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Low-Noise Detector Design for Measuring the Electric Conductivity of Liquids (액체의 전기 전도도 측정을 위한 저잡음 검출기 설계)

  • Kim, Nam Tae
    • Journal of the Institute of Electronics and Information Engineers
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    • v.49 no.9
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    • pp.287-292
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    • 2012
  • In this paper, design of a conductivity detector using a synchronous demodulation is presented to detect the electric conductivity of liquids with low noise. For the purpose, the detector is constructed by the combination of a carrier generator, conductivity detecting cell, and synchronous demodulator. The signal-to-noise ratio(SNR) of the detector is improved by adjusting the frequency bandwidth of the demodulator, whereby infinitesimal conductivity signals can easily be measured under various noise environments. As an application example, a conductivity detector, which is applied to the air monitoring in a fabrication process of semiconductor chips, is designed using the synchronous demodulation. The validity of the design technique is verified by experiments. Since experimental results are shown to approach the design performance of the detector, the synchronous demodulation proves to be useful to the design of a conductivity detector for measuring the infinitesimal electric conductivity of liquids.

A Study on the Optimum Design of Charge Pump PLL with Dual Phase Frequency Detectors (두 개의 Frequency Detector를 가지고 있는 Charge Pump PLL 의 최적설계에 관한 연구)

  • Woo, Young-Shin;Jang, Young-Min;Sung, Man-Young
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.10
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    • pp.479-485
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    • 2001
  • In this paper, we introduce a charge pump phase-locked loop (PLL) architecture which employs a precharge phase frequency detector (PFD) and a sequential PFD to achieve a high frequency operation and a fast acquisition. Operation frequency is increased by using the precharge PFD when the phase difference is within $-{\pi}{\sim}{\pi}$ and acquisition time is shortened by using the sequential PFD and the increased charge pump current when the phase difference is larger than ${\pm}{\pi}$. So error detection range of the proposed PLL structure is not limited to $-{\pi}{\sim}{\pi}$ and a high frequency operation and a higher speed lock-up time can be achieved. The proposed PLL was designed using 1.5 ${\mu}m$ CMOS technology with 5V supply voltage to verify the lock in process. The proposed PLL shows successful acquisition for 200 MHz input frequency. On the other hand, the conventional PLL with the sequential PFD cannot operate at up to 160MHz. Moreover, the lock-up time is drastically reduced from 7.0 ${\mu}s\;to\;2.0\;{\mu}s$ only if the loop bandwidth to input frequency ratio is regulated by the divide-by-4 counter during the acquisition process. By virtue of this dual PFDs, the proposed PLL structure can improve the trade-off between acquisition behavior and locked behavior.

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A Study on the Lightwave off-set Locking using Frequency Difference Detector (주파수 차이 검출기를 이용한 광파의 off-set 주파수 로킹 연구)

  • 유강희
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.8 no.2
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    • pp.484-493
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    • 2004
  • A new lightwave locking technique which can be used in tuning the wavelength of a local laser diode to the reference wavelength is presented in this paper. The optical frequency from the reference laser source and the optical frequency from the local slave VCO laser are heterodyned on a optical receiver, resulting in the 1.5GHz RF signal corresponding to the difference frequency between two input optical signals. The difference frequency is locked to the reference 1.5GHz oscillator source in off-set frequency locking loop. Using the commercialized microwave components, frequency difference detector can be easily established to lock the lightwave. The optical frequency of 1.55um laser diode which keeps the frequency off-set of 1.5GHz is locked to the input reference optical signal with the locking range of 320MHz.

Temperature Stable Frequency-to-Voltage Converter (동작온도에 무관한 Frequency-to-Voltage 변환 회로)

  • Choi, Jin-Ho;Yu, Young-Jung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.5
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    • pp.949-954
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    • 2007
  • In this work, temperature stable frequency-to-voltage converter is proposed. In FVC circuit input frequency is converted into output voltage signal. A FLL is similar to PLL in the way that it generates an output signal which tracks an input reference signal. A PLL is built on a phase detector, a charge pump, and a low pass filter. However, FLL does not require the use of the phase detector, the charge pump and low pass filter. The FVC is designed by using $0.25{\mu}m$ CMOS process technology. From simulation results, the variation of output voltage is less than ${\pm}2%$ in the temperature range $0^{\circ}C\;to\;75^{\circ}C$ when the input frequency is from 70MHz to 140MHz.