A Wide Band VCO with Automatic Frequency, Gain, and Two-Step Amplitude Calibration Loop for DTV Tuner Application

PU, YoungGun,LEE, Kang-Yoon The Institute of Electronics, Information and Comm 2009 IEICE transactions on electronics Vol.92 No.12

<P>This paper presents a wide tuning range VCO with an automatic frequency, gain, and two-step amplitude calibration loop for Digital TV (DTV) tuner applications. To cover the wide tuning range, the fully digital automatic frequency calibration (AFC) loop is used. In addition to the AFC loop, a two-step negative-G<SUB>m</SUB> tuning loop is proposed to provide the optimum negative-G<SUB>m</SUB> to the LC tank in a wide frequency range with a fine resolution. In the coarse negative-G<SUB>m</SUB> tuning loop, the number of active negative-G<SUB>m</SUB> cells is selected digitally based on the target frequency. In the fine negative-G<SUB>m</SUB> tuning loop, the negative-G<SUB>m</SUB> is tuned finely with the bias voltage of the VCO. Also, the digital VCO gain calibration scheme is proposed to compensate for the gain variation in a wide tuning range. The VCO tuning range is 2.6GHz, from 1.7GHz to 4.3GHz, and the power consumption is 2mA to 4mA from a 1.8V supply. The measured VCO phase noise is -120dBc/Hz at 1MHz offset.</P>

A 10-㎓ CMOS LC VCO with Wide Tuning Range Using Capacitive Degeneration

Tae-Geun Yu,Seong-Ik Cho,Hang-Geun Jeong 대한전자공학회 2006 Journal of semiconductor technology and science Vol.6 No.4

In order to widen the tuning range, capacitive degeneration is applied to fully CMOS LC VCOs. Small signal analysis shows that the fixed MOSFET capacitance seen by the LC tank is smaller than that of the traditional LC VCO, resulting in significant extension in the tuning range. This improvement in the tuning range has been verified through measurement of a 10-㎓ LC VCO fabricated by 0.18㎛ CMOS process. The measured tuning range is from 9.8-㎓ to 12-㎓, which is better than those of the reported CMOS LC VCOs in 10-㎓ band. The measured phase noise is - 103㏈c/㎐ at 1㎒ offset.

A 10-GHz CMOS LC VCO with Wide Tuning Range Using Capacitive Degeneration

Yu, Tae-Geun,Cho, Seong-Ik,Jeong, Hang-Geun The Institute of Electronics and Information Engin 2006 Journal of semiconductor technology and science Vol.6 No.4

In order to widen the tuning range, capacitive degeneration is applied to fully CMOS LC VCOs. Small signal analysis shows that the fixed MOSFET capacitance seen by the LC tank is smaller than that of the traditional LC VCO, resulting in significant extension in the tuning range. This improvement in the tuning range has been verified through measurement of a 10-GHz LC VCO fabricated by $0.18{\mu}m$ CMOS process. The measured tuning range is from 9.8-GHz to 12-GHz, which is better than those of the reported CMOS LC VCOs in 10-GHz band. The measured phase noise is - 103dBc/Hz at 1MHz offset.

PLL 기반 PWM/PFM 통합 제어 방식의 벅 컨버터

허정,정항근 대한전자공학회 2012 電子工學會論文誌-SD (Semiconductor and devices) Vol.49 No.8

DC-DC 컨버터에서 넓은 범위의 부하에 대하여 높은 효율을 유지하기 위해서는 PWM과 PFM을 함께 사용하는 듀얼 모드 제어 방식이 흔히 사용된다. 듀얼 모드 벅 컨버터는 부하 조건에 따라서 PWM이나 PFM을 선택해서 동작하므로, 모드 제어를 위한 부가 회로로 인하여 칩 면적이 증가하고 제어 방식이 변경되는 구간에서는 최적화된 효율을 얻을 수 없다. 본 논문에서는 전류 모드의 PWM 제어 회로에서 사용하는 발진기 대신에 PLL 기반의 발진기를 사용함으로써 추가적인 제어 회로 없이 PWM과 PFM의 통합된 제어 방식으로 동작하는 벅 컨버터를 제안함으로써 듀얼 모드 벅 컨버터의 단점을 해결했다. 제안한 통합 제어 방식의 벅 컨버터는 PSIM 시뮬레이션을 통하여 검증하였으며, 설계된 벅 컨버터 회로를 Cadence Spectre로 시뮬레이션 결과 250㎃의 부하에서 최대 효율은 94.7%이고 10㎃의 경부하에서 효율은 85.4%이다. In DC-DC converters, a PWM/PFM dual mode control method is commonly used to maintain a high efficiency over a wide range of load variation. Since the control mode is selected according to the load condition, the chip area is increased due to additional circuit for mode control and the optimum efficiency cannot be achieved around the mode transition point. To solve such problems, a new integrated control method is proposed in this paper, in which a PLL is used in the current mode PWM control circuit instead of an oscillator. The proposed integrated control method is verified through a design of a buck converter using PSIM simulation. Simulation of the complete buck converter circuit by Cadence Spectre showed a maximum efficiency of 94.7% at a load current of 250㎃ and an efficiency of 85.4% at a load current of 10㎃ under the light load condition.

Medium-Range Forecasting of Three Atmospheric Teleconnection Patterns for 2018 Heatwave Prediction in Korea by Global Ensemble Prediction System

Byoungheon Lee,Myong-In Lee,Nakbin Choi,Sunlae Tak 한국기상학회 2021 한국기상학회 학술대회 논문집 Vol.2021 No.10

Prediction of a heatwave is important to reduce the damage of heat-related illness including death. However, medium-range forecasting skill for a heatwave is not enough to provide early warning. Instead of direct forecasting of heatwaves based on temperature, this study aims to predict large-scale atmospheric teleconnection patterns related to a heatwave in Korea. It is found that three well-known teleconnection patterns; Arctic Oscillation (AO), Circumglobal Teleconnection pattern (CGT), and Pacific-Japan pattern (PJ) are independent of each other but strongly related with a heatwave in Korea. For example, all of the teleconnection patterns show a strong positive phase during record-breaking heatwave events such as 1994 and 2018. This study used Ensemble Prediction System for Global (EPSG) which is an operational global ensemble prediction system of the Korea Meteorological Administration (KMA). It has a 32km of horizontal resolution with 70 vertical levels and provides 25 ensemble members with 12 days forecasting in every 00UTC. Prediction skills of EPSG for daily indexes of AO, CGT, and PJ are examined during 2018 record-breaking heatwave events in Korea. Further, the role of teleconnection patterns for occurring heatwaves is discussed in a daily timescale.

Prediction Skill of the Tropical Intraseasonal Oscillation in the NCEP Dynamical Extended Range Forecasts

Kyong-Hwan Seo(서경환) 한국기상학회 2004 Asia-Pacific Journal of Atmospheric Sciences Vol.40 No.6

능동 인덕터를 이용한 광대역 디지털 제어 발진기의 설계

부영건(YoungGun Pu),박안수(AnSoo Park),박형구(HyungGu Park),박준성(Joon-Sung Park),이강윤(Kang-Yoon Lee) 大韓電子工學會 2011 電子工學會論文誌-SD (Semiconductor and devices) Vol.48 No.3

본 논문은 넓은 튜닝 범위와 정밀한 해상도 성능을 가지는 능동 인덕터를 이용한 디지털 제어 발진기에 대한 논문이다. 디지털 제어 발진기의 주파수를 조정하기 위해 능동 인덕터의 트랜스컨덕턴스를 디지털적으로 조정하는 구조를 제안하였으며, 디지털 제어 발진기의 이득 또한 디지털적으로 조정하여 이득 변화를 상쇄하도록 하였다. 또한, 넓은 튜닝 영역과 정밀한 해상도를 구현하기 위해 자동 3 단계 주파수 및 이득 튜닝 루프를 제안하였다. 디지털 제어 발진기의 총 주파수 튜닝 영역은 2.1㎓~3.5㎓로 1.4㎓의 영역으로 이는 2.4㎓의 중간 주파수에 대하여 58 %에 해당한다. 유효 주파수 해상도는 시그마 델타 모듈레이터를 사용하여 0.14 ㎑/LSB를 구현하였다. 제안하는 디지털 제어 발진기는 0.13 ㎛ CMOS 공정으로 설계 되었다. 전체 전력 소모는 1.2 V 공급전압에서 6.6 ㎽이며 위상 잡음 성능은 2.4 ㎓ 중간 주파수의 경우, 1 ㎒ 오프셋에서 -120.67 ㏈c/㎐ 성능을 보이고 있다. This paper presents a wide tuning range, fine-resolution DCO (Digitally Controlled Oscillator) with an active inductor. In order to control the frequency of the DCO, the transconductance of the active inductor is tuned digitally. In addition, the DCO gain needs to be calibrated digitally to compensate for gain variations. To cover the wide tuning range, an automatic three-step coarse tuning scheme is proposed. The DCO total frequency tuning range is 1.4 ㎓ (2.1 ㎓ to 3.5 ㎓), it is 58 % at 2.4 ㎓. An effective frequency resolution is 0.14 ㎑/LSB. The proposed DCO is implemented in 0.13 μm CMOS process. The total power consumption is 6.6 ㎽ from a 1.2 V supply voltage. The phase noise of the DCO output at 2.4 ㎓ is -120.67 ㏈c/Hz at 1 ㎒ offset.

Wide-Band Fine-Resolution DCO with an Active Inductor and Three-Step Coarse Tuning Loop

YoungGun Pu,AnSoo Park,Joon-Sung Park,Yeon-Kug Moon,김석기,이강윤 한국전자통신연구원 2011 ETRI Journal Vol.33 No.2

This paper presents a wide-band fine-resolution digitally controlled oscillator (DCO) with an active inductor using an automatic three-step coarse and gain tuning loop. To control the frequency of the DCO, the transconductance of the active inductor is tuned digitally. To cover the wide tuning range, a three-step coarse tuning scheme is used. In addition, the DCO gain needs to be calibrated digitally to compensate for gain variations. The DCO tuning range is 58% at 2.4 GHz, and the power consumption is 6.6 mW from a 1.2 V supply voltage. An effective frequency resolution is 0.14 kHz. The phase noise of the DCO output at 2.4 GHz is –120.67 dBc/Hz at 1 MHz offset.

2단계 자동 트랜스컨덕턴스 조절 기능을 가진 저전력, 광대역 전압제어 발진기의 설계

김상우(Sang Woo Kim),박준성(Joon-Sung Park),부영건(Young Gun Pu),허정(Jeong Hur),이강윤(Kang-Yoon Lee) 대한전자공학회 2010 電子工學會論文誌-SD (Semiconductor and devices) Vol.47 No.2

이 글은 공정, 전압, 온도 변화를 극복하기 위한 2단계 자동 트랜스컨덕턴스 조절 기능을 가진 저전력, 광대역 전압제어발진기의 설계에 관한 논문이다. 광대역에서 전압제어발진기를 발진시키기 위해, 디지털 자동 트랜스컨덕턴스 조절 루프와 아날로그 자동 진폭조절 루프가 사용되었다. 전압제어발진기의 출력 스윙 크기에 따라 트랜지스터의 바디전압을 조절하는 기능도 저전력 구현을 위해 설계되었다. 소모전류는 1.2 V 공급전압에서 2 ㎃에서 6 ㎃까지 1 ㎃ 단위로 조절된다. 전압제어발진기의 튜닝 범위는 2.35 ㎓에서 5 ㎓까지 2.65 ㎓로써 72%이다. 위상잡음은 중심주파수 3.2 ㎓를 기준으로 1 ㎒ 떨어진 지점에서 -117 ㏈c/㎐ 이다. This paper presents a low-power, wide tuning range VCO with automatic two-step negative-Gm calibration loop to compensate for the process, voltage and temperature variation. To cover the wide tuning range, digital automatic negative-Gm tuning loop and analog automatic amplitude calibration loop are used. Adaptive body biasing (ABB) technique is also adopted to minimize the power consumption by lowering the threshold voltage of transistors in the negative-Gm core. The power consumption is 2 ㎃ to 6 ㎃ from a 1.2 V supply. The VCO tuning range is 2.65 ㎓, from 2.35 ㎓ to 5 ㎓. And the phase noise is -117 ㏈c/㎐ at the 1 ㎒ offset when the center frequency is 3.2 ㎓.

Winding-number Excitation in One-dimensional Oscillators with Variable Interaction Range

홍현숙,김범준 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.7

At how long of an interaction range does an oscillator system behave as a fully-connected one? Toanswer this question, we consider a system of nonlocally-coupled phase oscillators in one dimension,and explore the effects of a variable interaction range L on collective dynamics. In particular,we investigate the winding-number distribution, paying particular attention to the existence of atwisted wave in the system, and observe that the twisted state vanishes when the interaction rangeexceeds a critical value. Finite-size scaling of the width of the winding-number distribution revealsthat the transition occurs at 2L/N 0.6, regardless of the system size N. We also show that at thesame transition point for the topological twisted state, the phase synchrony in the system becomespartial.