• Journal of the Institute of Electronics Engineers of Korea TC
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• v.45 no.7
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• pp.77-80
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• 2008

In this paper, low phase noise VCO using novel compact microstrip spiral resonator is proposed. A spiral resonator has super compact dimension, low insertion losses in the passband and high level of rejection in the stopband with sharp cutoff and a large coupling coefficient value, which makes a high Q value, and has reduced the phase noise. To increase the tuning range of VCO, varactor diode has been connected at the tunable negative resistance in VCO. This VCO has presented the oscillation frequency of $5.686{\sim}5.841GHz$, harmonics -29.83 dBc and phase noise of $-115.16{\sim}-115.17dBc/Hz$ at the offset frequency of 100 KHz.

• 한국정보통신설비학회:학술대회논문집
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• 2002.08a
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• pp.31-34
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• 2002

본 논문은 Ku-band(12.4-18 GHz) 위성통신 시스템 및 이동통신 중계기용 송수신부에 사용되는 고안정도 전압제어 유전체 공진기(Voltage Controlled Dieletric Resonator Oscillator)의 설계 및 제작에 대해 논하였다. 유전체 공진기(Dielectric Resonator)의 등가회로 모델을 이용하여 유전체 공진 발진기(Dielectric Resonator Oscillator)를 설계 알고리즘화 하였다. 유전체 공진 발진기와 바렉터 다이오드를 이용하여 13.4 GHz의 전압 제어 유전체 공진 발진기를 제작하였다. 이때의 출력 전력은 +12dBm이고 위상잡음은 offset 주파수 100kHz에서 -105 dBc/Hz로 측정되었다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.12 s.115
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• pp.1143-1149
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• 2006

The microstrip square open loop resonator has been employed to reduce the phase noise in VCO. The microstrip square open loop resonator has the large coupling coefficient value, which makes a high Q value, and has reduced the phase noise of VCO. To increase the tuning range of VCO, varactor diode has been connected at the tunable negative resistance in VCO. The output power and harmonic characteristics of VCO has been obtained 4.83 dBm and -28.83 dBc, respectively. The phase noise of VCO has been $-112.33{\sim}-116.16dBc/Hz$ @ 100 kHz in the tuning range, $5.735{\sim}5.845GHz$.

• Journal of Advanced Navigation Technology
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• v.8 no.1
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• pp.57-65
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• 2004

In this paper, keeping pace with light weight, pocket-size, lower-price, we design VCO(Voltage Controlled Oscillator) X/Ku band for using at public RD(Radar Detector) to apply to controlled voltage on base in transistor which used as a oscillator, without using varactor diode in part of VCO tuner. As a result of simulation, we conclude VCO could be have 110 MHz by controlled voltage 4.25 V to 4.80 V and show its output 9.63 dBm at operating frequency, 11.46 GHz, and its phase noise -107.2 dBc at 1 MHz offset frequency. So it turned out suitable performance for commercial use.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.12
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• pp.22-27
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• 2007

In this paper, a novel voltage-controlled oscillator (VCO) using the microstrip square open loop split ring resonator (OLSRR) is presented for reducing the phase noise. For this purpose, the square-shaped split ring resonator (SRR) haying the form of the microstrip square open loop is investigated. Compared with the microstrip square open loop resonator, the microstrip square OLSRR has the larger coupling coefficient value, which makes a higher Q value, and has reduced the phase noise of VCO. The VCO with 1.7V power supply has the phase noise of $-120\sim-116.5$ dBc/Hz @ 100 kHz in the tuning range, $5.746\sim5.854$ GHz. The figure of merit (FOM) of this VCO is $-200.33\sim-197$ dBc/Hz @ 100 kHz in the same tuning range.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.2
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• pp.25-34
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• 2010

This paper proposed a high-speed voltage-controlled ring-oscillator(VCRO) using a frequency doubling technique. The design of the proposed oscillator has been based on TSMC 0.18um 1.8V CMOS technology. The frequency doubling technique is achieved by AND-OR operations with 4 signals which have $90^{\circ}$ phase difference one another in one cycle. The proposed technique has been implemented using a 4-stage differential oscillator compose of differential latched inverters and NAND gates for AND and OR operations. The differential ring-oscillator can generate 4 output signals, which are $90^{\circ}$ out-of-phase one another, with low phase noise. The ANP-OR operations needed in the proposed technique are implemented using NAND gates, which is more area-efficient and provides faster switching speed than using NOR gates. Simulation results show that the proposed, VCRO operates in the frequency range of 3.72 GHz to 8 GHz with power consumption of 4.7mW at 4GHz and phase noise of ~-86.79dBc/Hz at 1MHz offset. Therefore, the proposed oscillator demonstrates superior performance compared with previous high-speed voltage-controlled ring-oscillators and can be used to build high-performance frequency synthesizers and phase-locked loops for radio-frequency applications.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.4
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• pp.906-911
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• 2004

In this paper, a VCDRO(Voltage Control Dielectric Resonator Oscillator) applied to FMCW(Frequency Modulated Continuous Wave)Radar as stable source is implemented and constructed with a MESFET(Metal-semiconductor Field-Effect Transistor) for low noise, a dielectric resonate. of high frequency selectivity, and high Q varator diode to obtain a good phase noise performance and stable sweep characteristics. The designed circuits is simulated thrash harmonic balance simulation technique to provide the optimum performance. The measured result of a fabricated VCDRO shows that output is 2.22㏈m at 12.05GHz, harmonic suppression -30㏈c, phase noise -130㏈c at 100KHz offset, and sweep range of varator diode $\pm$18.7MHz, respectively. This oscillator will be available to FMCW Radar.

• 한국ITS학회:학술대회논문집
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• 2008.11a
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• pp.625-628
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• 2008

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1399-1400
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• 2008

본 논문에서는 TSMC 0.18um 공정을 이용하여 2.45GHz 대역에서 동작하는 RFID 리더에 적용 할 수 있는 전압제어 발진기를 설계하였다. 위상 잡음 특성 향상을 위해 PMOS, NMOS 소자를 대칭으로 구성한 complementary cross-coupled LC 발진기 구조로 설계 하였고 MOS 배렉터를 이용하여 주파수를 가변 하였다. 또한 공정에서 사용되는 인덕터에 차폐 도체면(PGS:Patterned Ground Shield) 구조를 삽입했을 때 인덕터의 품질계수가 약 5.82% 향상되었고. 이에 따른 위상 잡음은 1MHz offset 주파수에서 PGS를 삽입하지 않는 구조에서는 -102.666dBc/Hz 이며, PGS 구조를 삽입한 구조는 -104.328dBc/Hz로 약1.662dBc 정도의 성능이 향상 되었다. 전압제어 발진기 Core 사이즈는 900um ${\times}$ 590um이고 주파수 가변 범위는 배렉터 전압 1.2${\sim}$2.1V에서 249MHz로 11.4% 특성을 보였다. 1.8V공급전압에서 5.76mW의 전력소모를 보였다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.2 s.117
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• pp.177-182
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• 2007

This paper presents the InGaP/GaAs HBT differential LC VCO with low phase noise performance for adaptive feedback interference cancellation system(AF-lCS). The VCO is verified with enhanced tank structure including filtering technique. The output tuning range for proposed VCO using asymmetric inductor and symmetric capacitors withlow pass filtering technique is 207 MHz. The output powers are -6.68 including balun and cable loss. The phase noise of this VCO at 10 kHz, 100 kHz and 1 MHz are -102.02 dBc/Hz, -112.04 dBc/Hz and -130.40 dBc/Hz. The VCO is designed within total size of $0.9{\times}0.9mm^2$.