• Title/Summary/Keyword: Phase Center Offset

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Design and Fabrication of YTO Module for Wideband Frequency Synthesizer (광대역 주파수 합성기용 YTO 모듈 설계 및 제작)

  • Chae, Myeong-Ho;Hong, Sung-Yong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.11
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    • pp.1280-1287
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    • 2012
  • The 3.2~6.5 GHz wideband YTO(YIG Tuned Oscillator) module is designed, fabricated and measured. To improve the phase noise characteristic of the YTO module, offset PLL(Phase Locked Loop) structure with sampling mixer is applied. This YTO module is composed of sampling mixer, phase detector, loop filter, current driver, and YTO. The phase noise of the fabricated YTO module is measured as -100 dBc/Hz at 10 kHz offset frequency, which approximates the predicted result at the center frequency of 4.5 GHz. This YTO module presents over 10 dB improved phase noise compared to conventional PLL module from operating frequency.

LP-Based Blind Adaptive Channel Identification and Equalization with Phase Offset Compensation

  • Ahn, Kyung-Sseung;Baik, Heung-Ki
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.28 no.4C
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    • pp.384-391
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    • 2003
  • Blind channel identification and equalization attempt to identify the communication channel and to remove the inter-symbol interference caused by a communication channel without using any known trainning sequences. In this paper, we propose a blind adaptive channel identification and equalization algorithm with phase offset compensation for single-input multiple-output (SIMO) channel. It is based on the one-step forward multichannel linear prediction error method and can be implemented by an RLS algorithm. Phase offset problem, we use a blind adaptive algorithm called the constant modulus derotator (CMD) algorithm based on condtant modulus algorithm (CMA). Moreover, unlike many known subspace (SS) methods or cross relation (CR) methods, our proposed algorithms do not require channel order estimation. Therefore, our algorithms are robust to channel order mismatch.

A DC-Offset Elimination Algorithm Based on an AR Model (AR모델을 이용한 직류 옵셋 성분 제거 알고리즘)

  • Chang Soo Young;Lee Dong Gyu;Kang Sang Hee
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.289-291
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    • 2004
  • ln this paper, A dc-offset elimination novel algorithm based on an An model is proposed. The algorithm can eliminate dc-offset rapidly than other algorithms. The signal of fault current can be presented as a linear equation combined sinusoidal with exponential signals. Then, the linear equation can be presented an auto-regressive(AR) model and do-offset can be calculated by the equation of AR model. So it is possible to be removed the dc-offset from the original current signal. Performance evaluation of the algorithm was tested on condition that A-phase ground fault on 154kV 25km overhead transmission line.

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A Study on Low Phase Noise Frequency Synthesizer Design for Ku-Band (KU-BAND 저 위상잡음 주파수 합성기 설계에 관한 연구)

  • Kim, Tae-Young
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.5
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    • pp.629-636
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    • 2014
  • In the proposed paper, we designed low phase noise frequency synthesizer for Ku-band. The proposed up-mixing frequency synthesizer consists of narrow local oscillation part and variable frequency oscillation part. To improve the phase noise of frequency synthesizer, we analyze how the configuration of frequency synthesizer affect the phase noise. The implemented frequency synthesizer reduce the phase noise. The phase noise is -95.18dBc/Hz at 7kHz frequency offset in 16GHz and -94.27dBc/Hz at 7kHz frequency offset in 16.125GHz.

A Method for Estimating an Instantaneous Phasor Based on a Modified Notch Filter

  • Nam Soon-Ryul;Sohn Jin-Man;Kang Sang-Hee;Park Jong-Keun
    • Journal of Electrical Engineering and Technology
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    • v.1 no.3
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    • pp.279-286
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    • 2006
  • A method for estimating the instantaneous phasor of a fault current signal is proposed for high-speed distance protection that is immune to a DC-offset. The method uses a modified notch filter in order to eliminate the power frequency component from the fault current signal. Since the output of the modified notch filter is the delayed DC-offset, delay compensation results in the same waveform as the original DC-offset. Subtracting the obtained DC-offset from the fault current signal yields a sinusoidal waveform, which becomes the real part of the instantaneous phasor. The imaginary part of the instantaneous phasor is based on the first difference of the fault current signal. Since a DC-offset also appears in the first difference, the DC-offset is removed trom the first difference using the results of the delay compensation. The performance of the proposed method was evaluated for a-phase to ground faults on a 345kV 100km overhead transmission line. The Electromagnetic Transient Program was utilized to generate fault current signals for different fault locations and fault inception angles. The performance evaluation showed that the proposed method can estimate the instantaneous phasor of a fault current signal with high speed and high accuracy.

A Study on Low Noise Frequency Synthesizer Design with Compact Size for Multi-Band (소형 다대역 저잡음 주파수 합성기 설계에 관한 연구)

  • Kim, Taeyoung;Han, Jonghoon
    • Journal of the Korea Institute of Military Science and Technology
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    • v.20 no.5
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    • pp.673-680
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    • 2017
  • In the proposed paper, we designed low noise frequency synthesizer with compact size for Multi-Band. The proposed frequency synthesizer consists of fundamental frequency band(2 GHz) and harmonic frequency band(4 GHz). To improve the phase noise and spurious level of frequency synthesizer, we analyze how the configuration of frequency synthesizer affect the phase noise and design the multi-band's structure. The implemented frequency synthesizer reduce both the phase noise and spurious level. The phase noise is -92.17 dBc/Hz at 1 kHz frequency offset in 2 GHz and -90.50 dBc/Hz at 1 kHz frequency offset in 4 GHz. All spurious signals including fundamental frequency are suppressed at least 20 dBc than the second harmonic frequency.

Fractional-N Frequency Synthesizer with a l-bit High-Order Interpolative ${\sum}{\Delta}$ Modulator for 3G Mobile Phone Application

  • Park, Byeong-Ha
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.2 no.1
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    • pp.41-48
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    • 2002
  • This paper presents a 18-mW, 2.5-㎓ fractional-N frequency synthesizer with l-bit $4^{th}$-order interpolative delta-sigma ($\Delta{\;}$\sum$)modulator to suppress fractional spurious tones while reducing in-band phase noise. A fractional-N frequency synthesizer with a quadruple prescaler has been designed and implemented in a $0.5-\mu\textrm{m}$ 15-GHz $f_t$ BiCMOS. Synthesizing 2.1 GHzwith less than 200 Hz resolution, it exhibits an in-band phase noise of less than -85 dBc/Hz at 1 KHz offset frequency with a reference spur of -85 dBc and no fractional spurs. The synthesizer also shows phase noise of -139 dBc/Hz at an offset frequency of 1.2 MHz from a 2.1GHz center frequency.

Aperture Coupled Cylindrical Resonator Oscillator (Aperture Coupled 원통형 공동 공진기 발진기)

  • 나인주;이정해
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.2
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    • pp.119-126
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    • 2003
  • In this paper, a cylindrical cavity resonator oscillator with high Q factor is designed and fabricated to improve the phase noise characteristic. A cavity resonator is coupled to oscillating circuit using aperture hole. Measured results show that the cylindrical cavity resonator oscillator (CRO) for Ku-band has less phase noise than the dielectric resonator oscillator (DRO) with the same oscillating circuit. It has output power of +3.92 dBm at the center frequency 13.4015250 GHz and phase noise of -109 dBc/Hz at 100 kHz offset.

Analysis and Optimization of Differential LC VCO with Filtering Technique in IoGaP/GaAs HBT Technology (InGaP/GaAs HBT 기반의 필터 기술을 이용한 차동 LC 전압조절발전기의 분석 및 최적화)

  • Qian, Cheng;Wang, Cong;Lee, Sang-Yeol;Kim, Nam-Young
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2008.11a
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    • pp.84-85
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    • 2008
  • In this paper, differential cross coupled LC VCOs with two noise frequency filtering techniques are proposed. Both VCOs are based on symmetric capacitor with asymmetric inductor tank structure. The VCO using low pass filtering technique shows low phase noise of -130.40 dBc/Hz at 1 MHz offset when the center frequency is 1.619 GHz. And the other VCO using band pass filtering technique shows -127.93 dBc/Hz at 1 MHz offset frequency when center frequency is 1.604 GHz. Two noise frequency filtering techniques are approached with different target.

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A Novel Phase Noise Reduction In Oscillator Using PBG(Photonic Band Gap) Structure and Feedforward Circuit

  • Seo, Chul-Hun
    • Journal of electromagnetic engineering and science
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    • v.5 no.4
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    • pp.204-207
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    • 2005
  • In this paper, PBG structure and feedforward circuit has been used to suppress the phase noise of the oscillator. Microstrip line resonator have low Q, but we can obtain high LO power by feedforward circuit and improve the resonator Q by the PBG, simultaneously. The proposed oscillator which uses PBG and feedforward circuit shows 0${\~}$20 dB phase noise reduction compared to the conventional oscillator. We have obtained -115.8 dBc of phase noise at 100 kHz offset from 2.4 GHz center.