• Journal of the Institute of Electronics Engineers of Korea TC
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• v.46 no.11
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• pp.56-60
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• 2009

In this paper, a novel voltage controlled oscillator (VCO) has been presented by using the microstrip square multiple spiral resonator for reducing the phase noise of VCO. The microstrip multiple square resonator has the large coupling coefficient value, which makes a high Q value, and has reduced phase noise of VCO. The VCO with 1.8 V power supply has phase noise of -115.0~-117.34 dBc/Hz @100 kHz in the tuning range, 8.935~9.4 GHz. When it has been compared with microstrip square multiple spiral resonator and coventional spiral resonator, the reduced Q value has been -32.7 dB and -57.6 dB respectively. This low phase noise VCO could ve available to a VCO in X-band.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.1
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• pp.68-72
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• 2004

The integrated voltage-controlled-oscillator(VOC) operating at 1.75 ㎓ is designed using the InGaP/GaAs HBT process. The proposed noise removal circuit and FR-4 substrate structure in this letter show the better characteristic of the phase noise and reduce the size of the VCO. The frequency tuning range of the VCO is about 200 ㎒ and the phase noise at 120 ㎑ offset is -119.3 ㏈c/㎐. The power consumption of the VCO core is 11.2 ㎽ at 2.8 V supply voltage and the output power is -2 ㏈m. The calculated figure of merit(FOM) is 191.7, which shows the best performance compared with the previous FET or HBT VCO.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.11
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• pp.1274-1281
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• 1988

A new voltage-controlled oscillator based on a voltage-controlled integrator has been developed. It consists of a Schmitt-trigger and a voltage-controlled integrator, which is realized by an operational transconductance amplifier (OTA) and a grounded capacitor. The input control voltage changes the time constant of the integrator, and hence the oscillation frequency. The SPICE simulation shows that a prototype circuit, which oscillates at 12.21 KHz at 0 V, has the conversion sencitivity 2,437 Hz/V and the residual nonlinearity less than 0.68% in a control voltage range from -2 V to 2 V. It also shows that the circuit provides a temperature drift less than + 250 ppm/$^{\circ}$C for frequencies up to 100 KHz.

• 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.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2001.10a
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• pp.630-633
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• 2001

본 논문에서는 2.3GHz대역의 WLL(무선가입자 회선망)에 사용하는 전압제어발진기를 설계하였다. 설계된 전압 제어 발진기는 3.2V, 10mA에서 동작하고 출력은 0.67dBm, 위상잡음 특성은 100kHz 옵셋 주파수에서 -102dBc/Hz이고 동조대역폭은 1V-3V의 전압변화에 2200∼2240MHz까지 40MHz의 동조 대역폭을 얻을 수 있었다. 따라서 제작된 전압제어 발진기는 무선가입자 회선망에 적용할 수 있다고 본다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.7B
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• pp.891-894
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• 2001

본 논문에서는 능동 배열 안테나에서 RF 대신 중간주파수를 이용하여 빔 추적을 하는 방법이 연구되었다. 안테나의 각 배열은 전압제어 발진기, 위상추적기, 혼합기와 결합되어 있으며 혼합기는 안테나 상에서 직접 RF 신호를 직접 중간주파수 신호로 변환시킨다. 전압제어 발진기 입력은 위상추적기에 의하여 조절되며 배열 안테나의 주사범위는 위상추적기와 전압제어발진기에 의하여 결정되었다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.1
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• pp.105-110
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• 2005

In this paper, a new technique to reduce the phase noise in microwave oscillators is proposed using the resonant characteristics of the Photonic Bandgap(PBG). We applied PBG structure to ground of the microstrip line resonator with the low Q(Quality factor). Therefore, we improved about 10 dBc in contrast to phase noise characteristic of the conventional microstrip line oscillator at 2.4 GHz ＠ 100 MHz offset. Output power is 7.09 dBm.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.1 s.4
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• pp.13-19
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• 2004

The VCO(Voltage Controlled Oscillator) with low phase noise and high reliability is implemented using nonlinear design, and its phase noise characteristics are compared with that of Lesson's equation. The microstripline coupled with dielectric resonator is realized as a high impedance inverter to improve the phase noise, and the qualify factor of resonator circuit can be transferred to active device with the enhanced the loaded quality factor. The worst case and part stress analyses are achieved to obtain the high reliability of VCO. The developed VCO has the oscillating tuning factor of 0.56MHz/V for the control voltage range of 0$\~$12V This VCO requires the DC power of 160mW. The phase noise characteristics exhibit good performances of -96.51dBc/Hz @ 10KHz and -116.3dBc/Hz @ 100KHz, respectively. And, the output power of 7.33 dBm is measured.

• Journal of IKEEE
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• v.18 no.4
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• pp.625-629
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• 2014

This study derives the asymptotic phase noise formula of the oscillators perturbed by the colored noises. Based on the derived formula, this study presents a sub-1V series-tuned differential Colpitts VCO. The ADS simulation result on the phase noise shows that the presented VCO exhibits about 3dBc/Hz lower phase noise at the 1MHz offset frequency from the oscillation frequency of 4.8GHz than the existing series-tuned differential Colpitts VCO with the inductor current sources.

• 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.