• 한국ITS학회:학술대회논문집
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• 한국ITS학회 2008년도 제7회 추계학술대회 및 정기총회
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• pp.376-379
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• 2008

• ETRI Journal
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• 제34권4호
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• pp.518-526
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• 2012

This paper proposes LC voltage-controlled oscillator (VCO) phase-locked loop (PLL) and ring-VCO PLL topologies with low-phase noise. Differential control loops are used for the PLL locking through a symmetrical transformer-resonator or bilaterally controlled varactor pair. A differential compensation mechanism suppresses out-band spurious tones. The prototypes of the proposed PLL are implemented in a CMOS 65-nm or 45-nm process. The measured results of the LC-VCO PLL show operation frequencies of 3.5 GHz to 5.6 GHz, a phase noise of -118 dBc/Hz at a 1 MHz offset, and a spur rejection of 66 dBc, while dissipating 3.2 mA at a 1 V supply. The ring-VCO PLL shows a phase noise of -95 dBc/Hz at a 1 MHz offset, operation frequencies of 1.2 GHz to 2.04 GHz, and a spur rejection of 59 dBc, while dissipating 5.4 mA at a 1.1 V supply.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(2)
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• pp.81-84
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• 2001

In recent years, the design of CMOS VCO at ever-higher frequencies has gained interest. This paper proposes an arithmetic functionality VCO circuit based on a differential ring oscillator for operating in high frequency. The proposed VCO architecture with half adder is able to produce two times higher frequency with my delay cell than conventional VCO produce double oscillation frequency and power dissipation is 14.59mW.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권3호
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• pp.207-212
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• 2013

A new CMOS voltage-bias differential LC voltage-controlled oscillator (LC-VCO) with active source degeneration is proposed. The proposed degeneration technique preserves the quality factor of the LC-tank which leads to improvement in phase noise of VCO oscillators. The proposed VCO shows the high figure of merit (FOM) with large tuning range, low power, and small chip size compared to those of conventional voltage-bias differential LC-VCO. The proposed VCO implemented in 0.18-${\mu}m$ CMOS shows the phase noise of -118 dBc/Hz at 1 MHz offset oscillating at 5.03 GHz, tuning range of 12%, occupies 0.15 $mm^2$ of chip area while dissipating 1.44 mW from 0.8 V supply.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2002년도 종합학술발표회 논문집 Vol.12 No.1
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• pp.21-24
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• 2002

This paper presents a fully integrated, wide tuning range differential CMOS voltage-controlled oscillator, tuned by pMOS-varactors. VCO utilizing a novel tuning scheme is reported. Both coarse digital tuning and fine analog tuning are achieved using pMOS-varactors. The VCO were implemented in a 0.18-fm standard CMOS process. The VCO tuned from 1.8㎓ to 2.55㎓ through 2-bit digital and analog input. At 1.8V power supply voltage and a total power dissipation of 8mW, the VCO features a phase noise of -126㏈c/㎐ at 3㎒ frequency offset.

• 대한전자공학회논문지SD
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• 제44권6호
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• pp.60-68
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• 2007

발진기를 구성하는 교차결합된 P형 및 N형 트랜지스터의 공통 소스 단자로부터 기본 발진주파수의 이차 고조파 신호를 차동으로 출력하는 전압조정발진기를 제안하였다. 공통소스단자의 임피던스를 최적화하고 발진기를 전압제한영역에서 동작시키면 차동 이차 고조파 신호가 모든 공정/온도/공급전압의 코너에서 진폭차와 위상차가 $0{\sim}1.6dB$ 이고 $+2.2^{\circ}{\sim}-5.6^{\circ}$ 범위 안에서 유지됨을 확인할 수 있었다. 또한 진폭/위상 오차를 보정할 수 있는 임피던스 튜닝 회로도 사용하였다. 제안된 구조를 검증하기 위해 5 GHz 차동 이차고조파를 발생하는 전압조정발진기를 $0.18-{\mu}m$ CMOS 공정을 통해 설계 제작하였다. 이차고조파의 차동출력의 차이인 에러 신호는 임피던스 튜닝 회로를 통하여 -70 dBm이라는 낮은 수준으로 측정되었다. 따라서 CMOS LC 전압조정발진기가 진폭차가 0.34 dB 이고 위상차가 $1^{\circ}$ 인 만족할만한 차동의 이차고조파 신호를 출력하고 있음을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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• pp.479-481
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• 2006

This paper describes a 2.5V, 320MHz low-noise and low-power Phase Locked Loop(PLL) using a noise-rejected Voltage Controlled ring Oscillator(VCO) fabricated in a TSMC 0.25um CMOS technology. In order to improve the power consumption and oscillation frequency of the PLL, The VCO consist of three-stage fully differential delay cells that can obtain the characteristic of high speed, low power and low phase noise. The VCO operates at 7MHz -670MHz. The oscillator consumes l.58mA from a 320MHz frequency and 2.5V supply. When the PLL with fully-differential ring VCO is locked 320MHz, the jitter and phase noise measured 26ps (rms), 157ps (p-p) and -97.09dB at 100kHz offset. We introduce and analysis the conditions in which ring VCO can oscillate for low-power operation.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.501-503
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• 2008

This paper presents the design of a 2.4 GHz low phase noise fully integrated LC Voltage-Controlled-Oscillator (VCO) in $0.18{\mu}m$ CMOS technology. The VCO is without any tail bias current sources for a low phase noise and, in which differential varactors are adopted for the symmetry of the circuit. At the same time, the use of differential varactors pairs reduces the tuning range, i.e., the frequency range versus VTUNE, so that the phase noise becomes lower. The simulation results show the achieved phase noise of -138.5 dBc/Hz at 3 MHz offset, while the VCO core draws 3.9mA of current from a 1.8V supply. The tuning range is from 2.28GHz to 2.55 GHz.

• 대한전자공학회논문지
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• 제27권11호
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• pp.83-91
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• 1990

전압제어 발진기(VCO:coltage controlled oscillator)는 FM 신호 변조, 주파수 안정기와 디지탈 클럭 재생과 같은 부분의 적용에 필수적인 기본회로이다. 본 논문에서는 BiCMOS 회로를 이용한 차동 증폭기를 사용하여 OTA(operational transconductance amplifier)회로와 OP amp를 설계하고 이를 토대로 하여 VCO 회로를 설계하였다. 그리고 이 VCO는 OTA와 전압 제어 적분기, 그리고 슈미트 트리거 회로로 구성이 되어 있다. 종래에는 CMOS를 사용하여 VCO를 설계하였지만 여기서는 구동능력이 좋은 BiCMOS를 사용하여 VCO를 설계하였다. 이 회로를 SPICE로 시뮬레이션 한 결과 출력 주파수는 105KHz에서 141KHz이며 변화 감도는 15KHz였다.

• ETRI Journal
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• 제31권6호
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• pp.755-764
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• 2009

This paper presents a switched self-biasing and a tail current-shaping technique to suppress the 1/f noise from a tail current source in differential cross-coupled inductance-capacitance (LC) voltage-controlled oscillators (VCOs). The proposed LC VCO has an amplitude control characteristic due to the creation of negative feedback for the oscillation waveform amplitude. It is fabricated using a 0.13 ${\mu}m$ CMOS process. The measured phase noise is -117 dBc/Hz at a 1 MHz offset from a 4.85 GHz carrier frequency, while it draws 6.5 mA from a 0.6 V supply voltage. For frequency tuning, process variation, and temperature change, the amplitude change rate of the oscillation waveform in the proposed VCO is 2.1 to 3.2 times smaller than that of an existing VCO with a fixed bias. The measured amplitude change rate of the oscillation waveform for frequency tuning from 4.55 GHz to 5.04 GHz is 131 pV/Hz.