삽입 가스의 부피 팽창을 이용한 탄소나노튜브 진동기

권오근,Kwon, Oh-Keun 한국전기전자재료학회 2005 전기전자재료학회논문지 Vol.18 No.12

We investigated a carbon nanotube (CNT) oscillator controlled by the thermal gas expansion using classical molecular dynamics simulations. When the temperature rapidly increased, the force on the CNT oscillator induced by the thermal gas expansion rapidly increased and pushed out the CNT oscillator. As the CNT oscillator extruded from the outer nanotube, the suction force on the CNT oscillator increased by the excess van der Waals(vdW) energy. When the CNT oscillator reached at the maximum extrusion point, the CNT oscillator was encapsulated into the outer nanotube by the suction force. Therefore, the CNT oscillator could be oscillated by both the gas expansion and the excess vdW interaction. As the temperature increased, the amplitude of the CNT oscillator increased. At the high temperatures, the CNT oscillator escaped from the outer nanotube, because the force on the CNT oscillator due to the thermal gas expansion was higher than the suction force due to the excess vdW energy. By the appropriate temperature controls, such as the maximum temperature, the heating rate, and the cooling rate, the CNT oscillator could be operated.

A Low Close-in Phase Noise 2.4 GHz RF Hybrid Oscillator using a Frequency Multiplier

Hyunwon Moon(문현원) 한국산업정보학회 2015 한국산업정보학회논문지 Vol.20 No.1

This paper proposes a 2.4 GHz RF oscillator with a very low close-in phase noise performance. This is composed of a low frequency crystal oscillator and three frequency multipliers such as two doubler (X2) and one tripler (X3). The proposed oscillator is implemented as a hybrid type circuit design using a discrete silicon bipolar transistor. The measurement results of the proposed oscillator structure show -115 dBc/Hz close-in phase noise at 10 kHz offset frequency, while only dissipating 5 mW from a 1-V supply. Its close-in phase noise level is very close to that of a low frequency crystal oscillator with little degradation of noise performance. The proposed structure which is consisted of a low frequency crystal oscillator and a frequency multiplier provides new method to implement a low power low close-in phase noise RF local oscillator.

A Low Close-in Phase Noise 2.4 GHz RF Hybrid Oscillator using a Frequency Multiplier

문현원 한국산업정보학회 2015 한국산업정보학회논문지 Vol.20 No.1

This paper proposes a 2.4 GHz RF oscillator with a very low close-in phase noise performance. This is composed of a low frequency crystal oscillator and three frequency multipliers such as two doubler (X2) and one tripler (X3). The proposed oscillator is implemented as a hybrid type circuit design using a discrete silicon bipolar transistor. The measurement results of the proposed oscillator structure show -115 dBc/Hz close-in phase noise at 10 kHz offset frequency, while only dissipating 5 mW from a 1-V supply. Its close-in phase noise level is very close to that of a low frequency crystal oscillator with little degradation of noise performance. The proposed structure which is consisted of a low frequency crystal oscillator and a frequency multiplier provides new method to implement a low power low close-in phase noise RF local oscillator.

근거리 레이더용 CMOS 저전력 교차 결합 전압 제어 발진기 설계 및 제작

김락영(Rak-Young Kim),김동욱(Dong-Wook Kim) 한국전자파학회 2010 한국전자파학회논문지 Vol.21 No.6

본 논문에서는 TSMC 0.13 ㎛ CMOS 공정을 사용하여 3가지 종류의 근거리 레이더용 저전력 교차 결합 전압 제어 발진기를 설계, 제작하였다. 기본적인 교차 결합 전압 제어 발진기는 24.1 ㎓를 중심으로 발진하도록 설계되었고, 이를 기본으로 저전력 동작을 위한 subthreshold 발진기가 설계되었다. 특히 큰 트랜지스터를 사용해야 하는 subthreshold 발진기에서 기생 캐패시터에 의해 발진 주파수가 낮아지는 문제점을 개선하기 위해 이중 공진 회로 구조를 발진기에 사용하는 것이 시도되었다. 제작된 CMOS 전압 제어 발진기는 종류에 따라 1 ㎒ offset 주파수에서 -101~-103.5 ㏈c/㎐의 위상 잡음, -11.85~-15.33 ㏈m의 출력 전력, 그리고 475~852 ㎒의 주파수 조정 범위들을 보였다. 전력 소모 측면에서는 기본적인 발진기가 5.6 ㎽를 사용하였고, 저 전력 subthreshold 회로는 3.3 ㎽를 사용하였다. 이중 공진 회로 구조의 subthreshold 발진기는 기본 발진기와 유사한 주파수 조정 범위를 유지하면서 상대적으로 작은 전력을 소모하고 개선된 위상 잡음 특성을 보였으며, 1 ㎽ DC 전력 기준의 figure-of-merit(FOM)이 약 3 ㏈ 가량 개선되어 -185.2 ㏈c의 값을 가졌다. In this paper, three kinds of 24 ㎓ low-power CMOS cross-coupled voltage controlled oscillators are designed and fabricated for a short-range radar applications using TSMC 0.13 ㎛ CMOS process. The basic CMOS crosscoupled voltage controlled oscillator is designed for oscillating around a center frequency of 24.1 ㎓ and subthreshold oscillators are developed for low power operation from it. A double resonant circuit is newly applied to the subthreshold oscillator to improve the problem that parasitic capacitance of large transistors in a subthreshold oscillator can push the oscillation frequency toward lower frequencies. The fabricated chips show the phase noise of -101~-103.5 ㏈c/㎐ at 1 ㎒ offset, the output power of -11.85~-15.33 ㏈m and the frequency tuning range of 475~852 ㎒. In terms of power consumption, the basic oscillator consumes 5.6 ㎽, while the subthreshold oscillator does 3.3 ㎽. The subthreshold oscillator with the double resonant circuit shows relatively lower power consumption and improved phase noise performance while maintaining a comparable frequency tuning range. The subthreshold oscillator with double resonances has FOM of -185.2 ㏈c based on 1 ㎽ DC power reference, which is an about 3 ㏈ improved result compared with the basic oscillator.

센서 네트워크를 위한 2.4 GHz 저잡음 커플드 링 발진기

심재훈 한국센서학회 2019 센서학회지 Vol.28 No.2

The voltage-controlled oscillator is one of the fundamental building blocks that determine the signal quality and power consumption in RF transceivers for wireless sensor networks. Ring oscillators are attractive owing to their small form factor and multi-phase capability despite the relatively poor phase noise performance in comparison with LC oscillators. The phase noise of a ring oscillator can be improved by using a coupled structure that works at a lower frequency. This paper introduces a 2.4 GHz low-noise ring oscillator that consists of two 3-stage coupled ring oscillators. Each sub-oscillator operates at 800 MHz, and the multi-phase signals are combined to generate a 2.4 GHz quadrature output. The voltage-controlled ring oscillator designed in a 65-nm standard CMOS technology has a tuning range of 800 MHz and exhibits the phase noise of −104 dBc/Hz at 1 MHz offset. The power consumption is 13.3 mW from a 1.2 V supply voltage.

Molecular Dynamics Study on the C60 Oscillator in a Graphene Nanoribbon Trench

강정원,이강환 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.65 No.2

Here, we present a C60 oscillator encapsulated in a graphene nanoribbon (GNR) trench. Themechanisms of the C60/GNR-trench oscillators are the same as those of the multi-walled carbonnanotube(CNT) oscillators. While the array synthesis of these CNT oscillators is very difficult,the same GNR trench array can be implemented by using current nanofabrication processes. Theoscillatory behaviors of a C60 oscillator sucked into a GNR trench were investigated in impulse dynamicsvia classical molecular dynamics simulations. The oscillatory motions of the C60 oscillatorin the GNR trench can be controlled by using the length and the width of the trench as structuralparameters because the restoring forces acting on the C60 oscillator are related to the width ofthe GNR trench and the length of the GNR trench is the direct distance of motion of the C60oscillator during translation. C60/GNR-trench nanostructures have a wide range of applications innanotechnology, such as shuttle memories and switches, sensors, and oscillators.

An X-Band Carbon-Doped InGaP/GaAs Heterojunction Bipolar Transistor MMIC Oscillator

Young-Gi Kim,민병규,김창우,Seong-Il Kim,Jong-Min Lee,Kyung Ho Lee 한국전자통신연구원 2005 ETRI Journal Vol.27 No.1

This paper addresses a fully-integrated low phase noise X-band oscillator fabricated using a carbon-doped InGaP heterojunction bipolar transistor (HBT) GaAs process with a cutoff frequency of 53.2 GHz and maximum oscillation frequency of 70 GHz. The oscillator circuit consists of a negative resistance generating circuit with a base inductor, a resonating emitter circuit with a microstrip line, and a buffering resistive collector circuit with a tuning diode. The oscillator exhibits 4.33 dBm output power and achieves –127.8 dBc/Hz phase noise at 100 kHz away from a 10.39 GHz oscillating frequency, which benchmarks the lowest reported phase noise achieved for a monolithic X-band oscillator. The oscillator draws a 36 mA current from a 6.19 V supply with 47.1 MHz of frequency tuning range using a 4 V change. It occupies a 0.8mm ×0.8 mm die area.

발진기의 성능평가를 위한 지그 회로의 개발

인치호(Chi-Ho Lin),윤달환(Dal-Hwan Yoon) 대한전자공학회 2008 電子工學會論文誌-SD (Semiconductor and devices) Vol.45 No.11

최근 발진수정자에 칩패키지를 결선한 SMD형의 적층세라믹 발진기를 많이 사용한다. 이러한 발진기들은 그 길이 및 패키지 내부의 패턴 등에 의하여 부유인덕턴스 및 기생 커패시턴스가 발생하고, 전원의 반사 및 잡음 발생으로 출력신호의 진폭감소 및 신호 손실이 발생하여 발진기 성능을 정상적으로 평가할 수 없다. 본 논문에서는 발진기와 계측기의 부정합임피던스로부터 발생한 신호 손실 및 진폭감소를 방지하기 위해 지그 회로를 개발한다. 이를 통하여 발진기의 정확한 스펙트럼 분석 및 성능을 평가함으로써 발진기의 성능향상을 기한다. We have used diversely the multilayer ceramic oscillator of the SMD(Surface Mounted Device) package technology that connects the crystal with the chip package. Such an oscillator occurs a stray inductance and a parasitic capacitance by the length and inner pattern. And it has been happened an amplitude attenuation and signal loss due to the reflection of power source and noise component. So we don't evaluate the precise performance of the oscillator for these factors. In this paper, we have developed the Jig system to evaluate the performance of the oscillator. Through this system, we will expect an advanced performance of the oscillator and redesign an oscillator of the low jitter characteristics and low phase noise.

기가헤르츠 오실레이터를 위한 BN 나노튜브 연구

이준하,Lee, Jun-Ha 한국반도체디스플레이기술학회 2007 반도체디스플레이기술학회지 Vol.6 No.1

The gigahertz oscillator behavior of double-walled boron-nitride nanotube (BNNT) was investigated by using classical molecular dynamics simulations. The BNNT oscillator characteristics were compared to carbon-nanotube (CNT) and hybrid-C@BNNT oscillators. The results show that the BNNT oscillators are higher than the van der Waals force of the CNT oscillator. Since the frictional effects of BNNT oscillators are higher than that of a CNT oscillator, the damping factors of BNNT and hybrid oscillators are higher than that of a CNT oscillator.

C형태의 DGS 공진기를 이용한 초고주파 발진기 설계

김기래(Kim, Gi-Rae) 한국정보전자통신기술학회 2015 한국정보전자통신기술학회논문지 Vol.8 No.4

위상 잡음 특성이 마이크로파 발진기에서 중요한 설계 요소가 되면서 위상잡음을 줄이기 위한 여러 방법의 연구 결과가 제안되었다. 이러한 방법들은 위상잡음을 줄이기 위해 공진기의 Q 값을 증대시키는데 초점을 맞추었다. 유전체 공진기는 높은 Q 값을 갖기 때문에 그동안 낮은 위상잡음을 갖는 마이크로파 발진기에 널리 사용되어 왔다. 그러나 이것은 입체적 구조로 되어 있기 때문에 초고주파 집적회로(MMIC)에 적용할 수가 어려웠다. 본 논문에서는 이러한 문제점을 해결하기 위해 평면형 구조이면서 위상잡음 특성을 개선할 수 있는 새로운 구조의 개방 링형 DGS 공진기를 제안하고, 이것을 이용하여 위상잡음 특성이 개선된 5.8GHz 대역의 발진기를 설계하였다. 개방 링형 DGS 공진기는 전송선로 밑면에 링 모양으로 식각된 접지면을 갖는 구조로 되어있다. 발진기의 특성은 5.8GHz의 기본 주파수에서 6.1dBm의 출력레벨과 -82.7 dBc@100kHz의 위상잡음 특성을 나타내었다. 이것은 마이크로스트립 공진기를 이용한 것보다 위상잡음 특성이 96.5dB 정도 개선되었다. Since phase noise is one of the most important parameters in the design of microwave oscillators, several methods have been proposed to reduce the phase noise. These methods have focused on improving the quality factor of resonators, which result in low phase noise oscillators. Dielectric resonators have been widely used for low phase noise in microwave oscillators due to their high quality factor. However this cannot be used in MMIC oscillators because they have a 3D structure. In this paper, to overcome this problem a novel resonator using open ring type DGS is proposed for improvement of phase noise characteristics that is weak point of oscillator using planar type microstrip line resonator, and oscillator for 5.8GHz band is designed using proposed DGS resonator. The open ring type DGS resonator is composed of DGS cell etched on ground plane under microstrip line. At the fundamental frequency of 5.8GHz, 6.1dBm output power and -82.7 dBc@100kHz phase noise have been measured for oscillator with ring type DGS resonator. The phase noise characteristics of oscillator is improved about 96.5dB compared to one using the general microstrip resonator.