• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.1
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• pp.131-137
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• 2014

A 120 GHz voltage controlled oscillator (VCO) with a divider chain including an injection locked frequency divider (ILFD) and six static frequency dividers is demonstrated using 65-nm CMOS technology. The VCO is designed based on the LC cross-coupled push-push structure and operates around 120 GHz. The 60 GHz ILFD at the first stage of the frequency divider chain is based on a similar topology as the core of the VCO to ensure the frequency alignment between the two circuit blocks. The static divider chain is composed of D-flip flops, providing a 64 division ratio. The entire circuit consumes a DC power of 68.5 mW with the chip size of $1385{\times}835{\mu}m^2$.

• Journal of the Korea Institute of Military Science and Technology
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• v.8 no.3 s.22
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• pp.64-72
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• 2005

In this paper, we propose a design method of the millimeter-wave(W-Band) waveguide cavity harmonic voltage controlled oscillator(VCO) using a Gunn diode for the armor sensor. Using the 3-dimensional simulation tool(Ansoft $HFSS^{TM}$), we were able to find the impedance matching point between waveguide and Gunn diode and estimate the oscillation frequency. A varactor diode is used for the frequency tuning, and we find out the equation for the calculation of the tunable frequency range. The designed VCO shows good performances; 17dBm output power at 94GHz center frequency, 520MHz frequency tuning range similar to the estimated value(480MHz).

• 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.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.12
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• pp.3215-3226
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• 1996

In this paper a K-band harmonic oscillator competitive to ordinary Push-Push type oscillators is introduced. This oscillator is composed of two-X-band dielectric resonance circuits. To favor its harmonic generation, the load effect and the bias effect are studied to allow the maximum harmonic distortion. As results, the dielectric resonated load and the class A bias are used for the 2nd harmonic generation. analytical study for modelling of voltage controlled dielectric resonator is carried out with theoretical background. The performance of the circuit is evaluated by simulation using harmonic balanced method. The novel structure has ont only a voltage tuning circuit but also an output port at fundamental frequency as the function of prescaler for phase lockede loop application on the just single oscillation structure. In experimentation, the output freqneyc of the 2nd harmonic signal is 20.5GHz and the maximum power level of output is +5.5dBm without additional post amplifiers. the harmonic oscillator exhibits -30dBc of high fundamental frequency rejection without added extra filters. The phase noise of -90dBc/Hz at 100kHz off-carrier has been achieved under free running condition, that satisfies phase noise requirement of IESS 308. The proposed oscillator may be utilized as the clean and stable fixed local oscillator in Transmit Block Upconvertor(TBU) or Low oise Block downconvertor(LNB) for K/Ka-band digital communications and satellite broadcastings.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.4
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• pp.484-494
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• 2014

We describe a digitally controlled oscillator (DCO) which compensates the frequency variations for process, voltage, and temperature (PVT) variations with an accuracy of ${\pm}2.6%$ at 2.5 GHz. The DCO includes an 8 phase current-controlled ring oscillator, a digitally controlled current source (DCCS), a process and temperature (PT)-counteracting voltage regulator, and a bias current generator. The DCO operates at a center frequency of 2.5 GHz with a wide tuning range of 2.2 GHz to 3.0 GHz. At 2.8 GHz, the DCO achieves a phase noise of -112 dBc/Hz at 10 MHz offset. When it is implemented in an all-digital phase-locked loop (ADPLL), the ADPLL exhibits an RMS jitter of 8.9 ps and a peak to peak jitter of 77.5 ps. The proposed DCO and ADPLL are fabricated in 65 nm CMOS technology with supply voltages of 2.5 V and 1.0 V, respectively.

• 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.

• 한국정보통신설비학회:학술대회논문집
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• 2006.08a
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• pp.179-182
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• 2006

This paper introduce a different-type voltage-controlled oscillator (VCO) for PLL frequency synthesizer, And also the architecture of a high speed low-power-consumption CMOS dual-modulus frequency divider is presented. It provides a new approach to high speed operation and low power consumption. The proposed circuits simulate in 0.35 um CMOS standard technology.

• The Journal of the Korea institute of electronic communication sciences
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• v.8 no.9
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• pp.1277-1283
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• 2013

In this paper, a novel voltage controlled oscillator(VCO) using CSRR loaded microstrip line for X-band RADAR is proposed. Using the microstrip line loaded CSRR inserted between the oscillator and buffer to the filter, the harmonic suppression has been improved. The measured results of the fabricated oscillator shows that its oscillation frequencies are from 9.28 to 9.39GHz according to the tuning voltage 0~10V, its output power level are about 16.6dBm at 9.35GHz. Compared with VCO using the conventional VCO, VCO using CSRR loaded microstirp, the harmonic suppression characteristic has been improved in 10.4dB

• 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.