• 제목/요약/키워드: wide tuning range

검색결과 112건 처리시간 0.021초

Fully Differential 5-GHz LC-Tank VCOs with Improved Phase Noise and Wide Tuning Range

  • Lee, Ja-Yol;Park, Chan-Woo;Lee, Sang-Heung;Kang, Jin-Young;Oh, Seung-Hyeub
    • ETRI Journal
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    • 제27권5호
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    • pp.473-483
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    • 2005
  • In this paper, we propose two LC voltage-controlled oscillators (VCOs) that improve both phase noise and tuning range. With both 1/f induced low-frequency noise and low-frequency thermal noise around DC or around harmonics suppressed significantly by the employment of a current-current negative feedback (CCNF) loop, the phase noise in the CCNF LC VCO has been improved by about 10 dB at 6 MHz offset compared to the conventional LC VCO. The phase noise of the CCNF VCO was measured as -112 dBc/Hz at 6 MHz offset from 5.5 GHz carrier frequency. Also, we present a bandwidth-enhanced LC VCO whose tuning range has been increased about 250 % by connecting the varactor to the bases of the cross-coupled pair. The phase noise of the bandwidth-enhanced LC-tank VCO has been improved by about 6 dB at 6 MHz offset compared to the conventional LC VCO. The phase noise reduction has been achieved because the DC-decoupling capacitor Cc prevents the output common-mode level from modulating the varactor bias point, and the signal power increases in the LC-tank resonator. The bandwidth-enhanced LC VCO represents a 12 % bandwidth and phase noise of -108 dBc/Hz at 6 MHz offset.

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SiGe HBT를 이용한 50MHz-3GHz 대역폭의 광대역 증폭기 IC 설계 (The Design of 50MHz-3GHz Wide-band Amplifier IC Using SiGe HBT)

  • 이호성;박수균;김병성
    • 한국전자파학회:학술대회논문집
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    • 한국전자파학회 2001년도 종합학술발표회 논문집 Vol.11 No.1
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    • pp.257-261
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    • 2001
  • This paper presents the implementation of wide-band RFIC amplifier operating from near 50MHz to 3GHz using Tachyonics SiGe HBT foundry. Voltage shunt feedback is used for the flat gain and the broad band impedance matching. Initial design parameters are calculated using the low frequency small signal analysis. Since the HBT model was not available at the design time, discrete tuning board was made for fine tuning in the low frequency range. Fabricated amplifier shows 12dB gain with 1dB fluctuation and PldB reaches 15dBm at 850MHz.

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무선 이동통신 단말에 응용 가능한 집적 필터회로 설계 (Integrated Filter Circuits Design for Mobile Communications)

  • 이광
    • 한국통신학회논문지
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    • 제38A권12호
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    • pp.991-997
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    • 2013
  • 본 논문에서는 아날로그필터를 위한 새로운 구조의 주파수 제어 방식(frequency tuning scheme)과 트랜스컨덕턴스(gm) 가변 범위가 넓은 트랜스컨덕터(OTA: Operational transconductor amplifier) 회로를 제안하였다. 제안된 주파수 제어 방식은 트랜스컨덕터와 커패시터로 구성된 1차 저역통과필터의 시정수와 커패시터에 일정 전압이 충전되는데 걸리는 시간과의 관계식을 이용한 것으로 전압제어필터 방식과 유사하게 간단한 구조를 가지며, 기준신호로 순수 정현파를 필요로 하지 않고, 시스템 클럭 또는 외부 수정 발진 회로를 통해 쉽게 얻을 수 있는 클럭 펄스를 사용할 수 있다는 장점이 있다. 또한, 클럭 주파수가 고정된 조건에서도 복잡한 구조의 커패시터 어레이를 사용하지 않고 다중 대역 지원을 목적으로 차단 주파수를 가변하면서 제어할 수 있다. 그리고 모의 실험을 통해 제안된 자동 주파수 제어회로의 동작을 확인하였다.

코오스와 파인 조정을 위한 다이나믹 주파수 스케일링 기법을 사용하는 CMOS 듀티 사이클 보정 회로 (A CMOS Duty Cycle Corrector Using Dynamic Frequency Scaling for Coarse and Fine Tuning Adjustment)

  • 한상우;김종선
    • 전자공학회논문지
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    • 제49권10호
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    • pp.142-147
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    • 2012
  • 본 논문에서는 다이나믹 주파수 스케일링 (DFS) 카운터를 사용하여 코오스, 파인 조정 기능을 갖는 CMOS 듀티 사이클 보정회로를 제시한다. DFS 카운터는 디지털-아날로그 컨버터의 비트 스위칭 글리치를 감소시키기 때문에 제안하는 CMOS 듀티 사이클 보정회로의 듀티 보정 범위를 증가시키고 지터 특성을 개선한다. 제안하는 회로는 0.18-${\mu}m$ CMOS 공정을 이용하여 설계되었다. 0.5-1.5GHz의 넓은 동작 주파수와 25-75%의 넓은 듀티 사이클 보정 범위 내에서 측정된 최대 출력 듀티 사이클 에러는 ${\pm}1.1%$이다.

Reconfigurable Multi-Band Mixer for SDR System

  • Kim, Jeong-Pyo;Choi, Jae-Hoon
    • Journal of electromagnetic engineering and science
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    • 제7권4호
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    • pp.154-160
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    • 2007
  • A reconfigurable multi-band mixer for the SDR system is proposed. The proposed reconfigurable mixer is operated between $850\;MHz{\sim}2\;GHz$, which includes all commercial mobile communication service. Because the varactor diodes are used to select a specific frequency and to adjust the impedance characteristic of the selected frequency band, the proposed reconfigurable mixer can be achieved to similar performance across all of the tuning range. In addition, the designed reconfigurable mixer is applicable for the SDR system since it has a single signal path for the multi-band signals and wide band tuning range.

Intelligent Fuzzy PID 제어 알고리즘을 이용한 실시간 OS 기반 복강경 수술 로봇의 위치 제어 성능 강화에 관한 연구 (A Study of Position Control Performance Enhancement in a Real-Time OS Based Laparoscopic Surgery Robot Using Intelligent Fuzzy PID Control Algorithm)

  • 송승준;박준우;신정욱;이덕희;김연호;최재순
    • 전기학회논문지
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    • 제57권3호
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    • pp.518-526
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    • 2008
  • The fuzzy self-tuning PID controller is a PID controller with a fuzzy logic mechanism for tuning its gains on-line. In this structure, the proportional, integral and derivative gains are tuned on-line with respect to the change of the output of system under control. This paper deals with two types of fuzzy self-tuning PID controllers, rule-based fuzzy PID controller and learning fuzzy PID controller. As a medical application of fuzzy PID controller, the proposed controllers were implemented and evaluated in a laparoscopic surgery robot system. The proposed fuzzy PID structures maintain similar performance as conventional PID controller, and enhance the position tracking performance over wide range of varying input. For precise approximation, the fuzzy PID controller was realized using the linear reasoning method, a type of product-sum-gravity method. The proposed controllers were compared with conventional PID controller without fuzzy gain tuning and was proved to have better performance in the experiment.

Electroabsorption modulator-integrated distributed Bragg reflector laser diode for C-band WDM-based networks

  • Oh-Kee Kwon;Chul-Wook Lee;Ki-Soo Kim
    • ETRI Journal
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    • 제45권1호
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    • pp.163-170
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    • 2023
  • We report an electroabsorption modulator (EAM)-integrated distributed Bragg reflector laser diode (DBR-LD) capable of supporting a high data rate and a wide wavelength tuning. The DBR-LD contains two tuning elements, plasma and heater tunings, both of which are implemented in the DBR section, which have blue-shift and red-shift in the Bragg wavelength through a current injection, respectively. The light created from the DBR-LD is intensity-modulated through the EAM voltage, which is integrated monolithically with the DBRLD using a butt-joint coupling method. The fabricated chip shows a threshold current of approximately 8 mA, tuning range of greater than 30 nm, and static extinction ratio of higher than 20 dB while maintaining a side mode suppression ratio of greater than 40 dB under a window of 1550 nm. To evaluate its modulation properties, the chip was bonded onto a mount including a radiofrequency line and a load resistor showing clear eye openings at data rates of 25 Gb/s nonreturn-to-zero and 50 Gb/s pulse amplitude modulation 4-level, respectively.

운행자동차 성능 및 배기 배출물에 미치는 흡기 다기관, 흡기 파이프 및 공기필터의 튜닝효과에 관한 연구 (A Study on Tuning Effects of Intake Manifold, Intake Pipe and Air Filter upon Performance and Exhaust Emissions of Driving Car)

  • 배명환;구영진;박희성
    • 한국자동차공학회논문집
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    • 제24권5호
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    • pp.538-548
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    • 2016
  • The purpose of this study is to identify the possibility of effective tuning works, understand the characteristics of tuning engine, and analyse the basic data of engine tuning inspection corresponding to the safe operation and environment of a driving gasoline car. The effects of tuning on the characteristics of performance and exhaust emissions under a wide range of engine speeds are experimentally investigated by the actual driving car with a four-cycle, four-cylinder DOHC, turbo-intercooler, water-cooled gasoline engine operating at four types of non-tuning, tuning 1, 2 and 3. The tuning parts in the gasoline engine are the intake manifold, intake pipe and air filter. In the experiment, the output, torque and air-fuel ratio of the five-speed automatic transmission vehicles were measured at the chassis dynamometer(Dynojet 224xLC) with one person on board. The exhaust emissions of $NO_X$, THC, CO, $O_2$ and $CO_2$, and excess air ratio(${\lambda}$) at the other chassis dynamometer(DASAN-MD-ASM-97-KR-HD) were also measured by the idle/constant-speed mode(ASM2525 mode) test method. It is found that the actual air-fuel ratios of non-tuning and tuning engines were shown to be lower than the stoichiometric air-fuel ratio with increasing engine speed, and the actual air-fuel ratio of non-tuning engine was slightly higher than those of tuning engines when the engine speed is more than 4000 rpm. The output was significantly increased by the tuning whereby the maximum output of tuning engine was more increased to approximately 117.64% than that of non-tuning engine. In addition, CO, THC and $NO_X$ emissions of non-tuning and tuning engines measured by the constant-speed test mode were all satisfied with the inspection standards. CO emission was increased, while THC and $NO_X$ emissions were reduced by tuning.

능동 인덕터를 이용한 0.15-㎛ GaAs pHEMT 기반 W-대역 VCO 설계 (A W-band Compact and Wideband VCO Using Active Inductor in 0.15-㎛ GaAs pHEMT Technology)

  • 김동교
    • 전기전자학회논문지
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    • 제28권3호
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    • pp.445-450
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    • 2024
  • 본 논문에서는 0.15-㎛ GaAs pHEMT 공정을 이용하여 설계된 버랙터 없는 W-band(75-110 GHz) 전압제어 발진기(VCO)를 소개한다. 능동 인덕터를 활용하여 버랙터 없는 주파수 조절을 구현하였으며 능동 인덕터 회로는 게이트가 종단된 공통 게이트 스테이지를 이용하였다. 해당 능동 인덕터는 시뮬레이션 결과 기존의 버랙터 다이오드와 비교하여 넓은 주파수 조절 범위와 높은 Q-인자를 갖는다. 발진기 코어는 소스 피드백이 포함된 Colpitts 구조를 사용하였다. 구현된 버랙터 없는 W-band VCO의 측정 결과 88 GHz에서 5.7 dBm의 높은 출력 전력과 5.8 %의 주파수 조절 범위를 얻었으며 이 때 dc 전력 소모는 146 mW였다. 또한 해당 회로는 컴팩트한 레이아웃 디자인을 통해서 0.48 mm2의 작은 사이즈로 구현되었다.

Optimal placement and tuning of multiple tuned mass dampers for suppressing multi-mode structural response

  • Warnitchai, Pennung;Hoang, Nam
    • Smart Structures and Systems
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    • 제2권1호
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    • pp.1-24
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    • 2006
  • The optimal design of multiple tuned mass dampers (multiple TMD's) to suppress multi-mode structural response of beams and floor structures was investigated. A new method using a numerical optimizer, which can effectively handle a large number of design variables, was employed to search for both optimal placement and tuning of TMD's for these structures under wide-band loading. The first design problem considered was vibration control of a simple beam using 10 TMD's. The results confirmed that for structures with widelyspaced natural frequencies, multiple TMD's can be adequately designed by treating each structural vibration mode as an equivalent SDOF system. Next, the control of a beam structure with two closely-spaced natural frequencies was investigated. The results showed that the most effective multiple TMD's have their natural frequencies distributed over a range covering the two controlled structural frequencies and have low damping ratios. Moreover, a single TMD can also be made effective in controlling two modes with closely spaced frequencies by a newly identified control mechanism, but the effectiveness can be greatly impaired when the loading position changes. Finally, a realistic problem of a large floor structure with 5 closely spaced frequencies was presented. The acceleration responses at 5 positions on the floor excited by 3 wide-band forces were simultaneously suppressed using 10 TMD's. The obtained multiple TMD's were shown to be very effective and robust.