• Journal of the Microelectronics and Packaging Society
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• v.8 no.1
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• pp.61-64
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• 2001

VCO(Voltage Contolled Oscillator) is one of the main components governing the size, performance and power consumption of telecommunication devices. As the devices become much smaller, YCO need to hove much smaller size with better characteristics. Buried type passive components of L, C, R were developed previously and the structure of these components are good for minimizing the size of VCO. Our own library of passive components is used in simulation and measurement circuit designed by ourselve. In structure of multi-layered VCO, some components governing the characteristics of VCO are selected and placed on the top of oscilltor for the good tuning process. In resonator part, the stripline structure and low loss glass/ceramic material are used to get higher Q value. In our research, a VCO oscillates in the 2.3~2.36 GHz band is developed.

• Proceedings of the IEEK Conference
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• 2006.06a
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• pp.605-606
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• 2006

Voltage Controlled Oscillator(VCO) plays an important role in today's communication systems. Especially, a Clock Generator(CG) in phase-locked loop(PLL) is usually realized by the VCO. This paper proposes a new VCO with a controllable duty cycle buffer, that can be adopted in low-power high-speed communication systems. Delay cell of the VCO is implemented with gilbert cell. Frequency dynamic range of the VCO is in the range of approximately $50MHz{\sim}500MHz$. Parameters with N-well CMOS 0.18-um process with 1.8V supply voltage was used for the simulations.

• The Journal of the Acoustical Society of Korea
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• v.16 no.4
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• pp.76-84
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• 1997

In this paper, one of the core components of a mobile communication system, VCO(Voltage Controlled Oscillator) IC is designed. The VCO IC was designed, have realized as LC turned oscillator using varicap. LC sinusoidal tuned oscillator generally requires external inductors and thus remainding circuit is implemneted in monolithic IC. The circuit is fabricated using an 15 mask IC process and has a die size of 1150um${\times}$780um. The tests showed that VCO was operated at frequencies in the regions between 880MHz-915MHz in the control voltage range of 1V to 3V at 5V supply voltage and as the power supply was varied from 4.5V to 5.5V, the frequency varied 425KHz/V. The VCO IC has frequency shift of 1.97MHz/T, carrier level of -7dBm and power consumption of 16.7mA. Also it has phase noise of -80dBc/Hz, offset at 50KHz and harmonic response of center frequency is -41dBm. For the future development of the transceiver 1 chip, the previously mentioned external devices need to be incorporated into Si MMIC.

• Journal of IKEEE
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• v.19 no.4
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• pp.465-471
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• 2015

An LC-tuned sinusoidal voltage-controlled oscillator (VCO) using temperature-stable linear operational transconductance amplifiers (OTAs) is presented. Its architecture is based on Hartley oscillator configuration, where the inductor is active one realized with two OTAs and a grounded capacitor. Two diode limiters are used for limiting amplitude. A prototype oscillator built with discrete components exhibits less than 3.1% nonlinearity in its current-to-frequency transfer characteristic from 1.99 MHz to 39.14 MHz and $220ppm/^{\circ}C$ frequency stability to the temperature drift over 0 to $75^{\circ}C$. The total harmonic distortion (THD) is as low as 4.4 % for a specified frequency-tuning range. The simulated phase noise of the VCO is about -108.9 dBc/Hz at 1 MHz offset frequency in frequency range of 0.4 - 46.97 MHz and property of phase noise of VCO is better than colpitts-VCO.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.293-297
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• 2009

In this thesis, design of a VCO(Voltage controlled Oscillator) with a novel tuning mechanism is presented for the Radar system. This circuit, the 9.5 GHz oscillator is designed and implemented by restructuring microstrip resonator to raise Q value and to require a wide frequency tuning range. This product is fabricated on 2.6 Teflon substrate and device is NE722S01. In this paper, The new microstrip resonator VCO is proposed to achieve the characteristic of a wide frequency tuning range. This microstrip resonator VCO shows the phase noise characteristic of -108.3 dBc/Hz at 1 MHz offset from the fundamental frequency, the output power of 5.7 dBm and the second harmonic suppression of -38 dBc for the VCO are obtained. The manufacture VCO shows a frequency tuning range of 193.8 MHz. The proposed micro trip resonator VCO can be used for X-band Radar System with required tuning range.

• Proceedings of the IEEK Conference
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• summer
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• pp.218-220
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• 2004

A new wide-band VCO topology using Miller capacitance is proposed. Contrary to conventional VCO using the Miller capacitance where the variable amplifier gain is negative, the proposed VCO uses both the negative and positive variable amplifier gain to enhance the frequency tuning range significantly. The proposed VCO is simulated using HSPICE. The simulations show that 410MHz and 220MHz frequency tuning range are obtained using the negative .and positive variable amplifier gain, respectively. The tuning range of the proposed VCO is $23\%$ of the center frequency(2.8GHz). The phase noise is -104dBc/Hz at 1MHz offset by simple model. The operating current is only 3.84mA at 2.5V power supply.

• JSTS:Journal of Semiconductor Technology and Science
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• v.13 no.3
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• pp.207-212
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• 2013

A new CMOS voltage-bias differential LC voltage-controlled oscillator (LC-VCO) with active source degeneration is proposed. The proposed degeneration technique preserves the quality factor of the LC-tank which leads to improvement in phase noise of VCO oscillators. The proposed VCO shows the high figure of merit (FOM) with large tuning range, low power, and small chip size compared to those of conventional voltage-bias differential LC-VCO. The proposed VCO implemented in 0.18-${\mu}m$ CMOS shows the phase noise of -118 dBc/Hz at 1 MHz offset oscillating at 5.03 GHz, tuning range of 12%, occupies 0.15 $mm^2$ of chip area while dissipating 1.44 mW from 0.8 V supply.

• Journal of electromagnetic engineering and science
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• v.16 no.3
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• pp.191-193
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• 2016

This paper proposes a voltage-controlled oscillator (VCO) that has broadband turning and low-level of phase noise characteristics. Due to the micro-strip line resonant circuit with a low Q value, which is applied to the broadband tuning range, the depreciated phase noise performance is compensated by restraining the harmonics of the oscillating frequency. The VCO was designed according to the proposed structure as well as the conventional structure, and the superiority of the proposed structure was verified through its simulation, fabrication, and measurement.

• Journal of IKEEE
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• v.24 no.4
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• pp.975-981
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• 2020

A 10 GHz LC voltage-controlled oscillator (VCO), which controls an amplitude of output signal, is proposed to improve the phase noise. The proposed amplitude control circuit for the LC VCO consists of a peak detector, an amplifier, and a current source. The peak detector is performed detecting the lowest voltage of the output signal by using two diode-connected NMOSFET and a capacitor. The proposed 10 GHz LC VCO with an amplitude control circuit for output signal is designed using a 55 nm CMOS process with a supply voltage of 1.2 V. Its area is 0.0785 ㎟. The amplitude control circuit used in the proposed LC VCO reduces the amplitude variation 242 mV generated in the output signal of the conventional LC VCO to 47 mV. Furthermore, it improves the peak-to-peak time jitter from 8.71 ps to 931 fs.

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.4
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• pp.437-444
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• 2015

A high output power voltage controlled oscillator (VCO) in the U-band was implemented using a 65 nm CMOS process. The proposed VCO used a transmission line to increase output voltage swing and overcome the limitations of CMOS technologies. Two varactor banks were used for fine tuning with a 5% frequency tuning range. The proposed VCO showed small variation in output voltage and operated at 51.55-54.18 GHz. The measured phase noises were -51.53 dBc/Hz, -91.84 dBc/Hz, and -101.07 dBc/Hz at offset frequencies of 10 kHz, 1 MHz, and 10 MHz, respectively, with stable output power. The chip area, including the output buffer, is $0.16{\times}0.16mm^2$ and the maximum output power was -0.11 dBm. The power consumption was 33.4 mW with a supply voltage of 1.2-V. The measured $FOM_P$ was -190.8 dBc/Hz.