• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.9
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• pp.961-966
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• 2009

In this paper, a novel voltage-controlled oscillator(VCO) using the metamaterial broadside coupled spiral resonators(BC-DSRs) is presented for reducing the phase noise. For reducing of the phase noise, the series spiral structures have been applied for the signal plane and ground plane at each in order to have the large coupling. Compared with the conventional VCO, the proposed VCO has the larger coupling coefficient constant, which makes a higher Q-factor and has reduced the phase noise of the VCO. The proposed VCO has the phase noise of $-121{\sim}-117.16\;dBc$/Hz at 100 kHz in the tuning range, $5.749{\sim}5.853\;GHz$. The figure of merit(FOM) of this VCO is $-198.45{\sim}-194.77\;dBc$/Hz at 100 Hz in the same tuning range, respectively.

• 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.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.12
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• pp.2589-2594
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• 2012

In this paper, a novel resonator using 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 5.8 GHz band is designed using proposed DGS resonator. The ring type DGS resonator is composed of DGS cell etched on ground plane under $50{\Omega}$ microstrip line. At the fundamental frequency of 5.8 GHz, 7.6 dBm output power and -82.7 dBc@100kHz phase noise have been measured for oscillator with ring type DGS resonator. We designed the voltage controlled oscillator using proposed the DGS resonator with varactor diodes placed between gaps of DGS. Thus, due to its simple fabrication process and planar type, it is expected that the technique in this paper can be widely used for low phase noise oscillators for both MIC and MMIC applications.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.44 no.11
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• pp.60-66
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• 2007

In this paper, a novel voltage-controlled oscillator (VCO) using the microstrip square open loop multiple split ring resonator (OLMSRR) is presented for reducing the phase noise property. The square-shaped multiple split ring resonator (MSRR) having the form of the microstrip square open loop is investigated to realize this property. Compared with the microstrip square open loop resonator and the microstrip square open loop split ring resonator (OLSRR) as well as the conventional microstrip line resonator, the microstrip square OLMSRR 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 suppIy has the phase noise of $-124.5\;{\sim}\;-122.0\;dBc/Hz$ @ 100 kHz in the tuning range, $5.746\;{\sim}\;5.84\;GHz$. The figure of merit (FOM) of this VCO is $-203.96\;{\sim}\;-201.6\;dBc/Hz$ @ 100 kHz in the same tuning range. Compared with VCO using the conventional microstrip line resonator, VCO using the microstrip square open loop resonator and VCO using microstrip square OLSRR, the phase noise property of VCO using the proposed resonator has been improved in 25.66 dB, 8.34 dB, and 4.5 dB, respectively.

• 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.

• 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 $0.9{\times}0.9mm^2$.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.13 no.1
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• pp.60-67
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• 2002

In this paper, the dual band VCO of mobile communication terminal using oscillation part switching circuit is proposed. In order to model the VCO accurately, the resonator is converted the equivalent circuit which is analyzed to use numerical method and designed optimal the dual band VCO operating GSM and DCS band. In order to demonstrate the objective theory of the proposed VCO, the dual band VCO is designed and experimented. The results of experiment, it is conformed that the VCO can be used mobile communication hand phone and components of three generation mobile communication systems.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.3
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• pp.269-281
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• 2014

In this paper, a systematic design of a low phase noise voltage-tuned dielectric resonator oscillator(VTDRO) using loop group delay is proposed. Designed VTDRO is closed-loop type and consists of a cascade connection of a resonator, phase shifter, and amplifier. Firstly, a reference VTDRO is fabricated and its phase noise and electrical frequency tuning range are measured. Both the phase noise and electrical frequency tuning range depend on the loop group delay. Then, a required value of loop group delay for a new VTDRO with a low phase noise can be systematically computed. In addition, its phase noise and electrical frequency tuning range can be theoretically estimated using those obtained from the measurement of the reference VTDRO. When the loop group delay increases, the phase noise decreases and the electrical frequency tuning range also decreases. The former predominantly depends on the resonator structure. Therefore we propose a systematic design procedure of a resonator with high group delay characteristics. The measured loop group delay of the new VTDRO is about 700 nsec. The measured phase noise of the new VTDRO show a state-of-the-art performance of 154.5 dBc/Hz at 100 kHz frequency offset and electrical frequency tuning range of 448 kHz for a voltage change of 0~10V. The oscillation power is about 4.39 dBm.

• 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.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, $5.735{\sim}5.845GHz$.