• Korean Journal of Optics and Photonics
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• v.30 no.4
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• pp.154-158
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• 2019

We have used a mid-IR (mid-infrared) continuous-wave (cw) optical parametric oscillator (OPO), developed previously and described in Ref. 12, to build a performance-evaluation setup for a mid-IR spectrometer. The used CW OPO had a wavelength tuning range of $ 2.5-3.6{\mu}m$ using a pump laser with a wavelength of 1064 nm and a fan-out MgO-doped periodically poled lithium niobate (MgO:PPLN) nonlinear crystal in a concentric cavity design. The OPO was combined with a near-IR integrating sphere and a Fourier-transform IR optical spectrum analyzer to build a performance-evaluation setup for mid-IR spectrometers. We applied this performance-evaluation setup to evaluating a mid-IR spectrometer developed domestically, and demonstrated the capability of evaluating the performance, such as spectral resolution, signal-to-noise ratio, spectral stray light, and so on, based on this setup.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.217-219
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• 2009

본 논문에서는 NE6510179A 트랜지스터를 사용하고, 나선형 공진기를 이용하여 단일 고출력 발진기를 설계 측정하였다. 발진기의 출력과 주파수 선택을 공진기가 결정하므로, 공진기중에 Q값이 높은 나선형 공진기를 선택하였다. 이를 ADS Momentum을 이용하여 설계하여 제작 및 측정을 하였다. 이 때 측정된 단일 고출력 발진기의 성능은 22.61dBm @ 1.74GHz로 측정되었고, 위상잡음은 -146.76dBc/Hz @ 1MHz offset으로 측정 되었다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.43 no.4 s.310
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• pp.45-52
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• 2006

In his paper, we have developed the SMD(surface mounted device) type PECL(positive emitter-coupled logic) VCXO of the $5{\times}7mm$ size for gratifying the requested specifications and the multilayer ceramic SMD(surface mounted device) package technology. The VCXO wired with the PECL(positive emitter coupled logic) package take place a stray inductance and a parasitic capacitance by the length and the inner pattern of the VCXO and the amplitude attenuation and signal loss due to the reflection of power source and the noise component. We have developed the Zig system to analyze the precise spectrum and evaluate the performance. The basic operating voltage is the 3.3 V and have the frequency range of 120MHz-180MHz. The Q factor is over 5K and it has the low jitter characteristics of 3.5 ps and low phase noise.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.7A
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• pp.947-954
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• 1999

A new low phase noise Dielectric Resonator Parallel Feedback Oscillator(DRPFO) that is proposed in this paper has a simple structure so that it can be fabricated in low cost and with high performance. The proposed DRPFO is in a feedback loop oscillator configuration, which is composed of a low noise amplifier, a power amplifier, a power attenuator, a power divider and a parallel resonator feedback element that consists of a dielectric resonator coupled with two microstrip lines. The measured phase noise of DRPFO was less than -81 dBc/Hz at offset frequency 1 kHz of 10.75 GHz carrier frequency, and the frequency stability of DRPFO was less than $\pm$200 kHz over the temperature range of -40$^{\circ}$C to +60$^{\circ}$C.

• 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 Korea Academia-Industrial cooperation Society
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• v.10 no.10
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• pp.2639-2645
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• 2009

This paper describes a CPW oscillator using a spiral resonator. Spiral resonators are very useful in design CPW oscillators since they show a relatively higher Q than CPW hairpin and helical resonators. Prior to the design of oscillators, three CPW resonators are designed and compared. Electromagnetic (EM) simulation are performed for an improved design in design the CPW resonators and oscillators. Three oscillators are designed at 5.7 GHz using the mentioned CPW resonators. The measured output power of three CPW oscillators using the helical, hairpin, and spiral resonators are 2.55 dBm, 2.64 dBm, and 4.98 dBm, respectively. In addition, the size of three resonators are $102.15mm^2,\;130.05mm^2,\;80.625mm^2$, respectively, so it is proven that the proposed CPW oscillator using the spiral resonator has a smaller size than the others.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.48 no.3
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• pp.34-41
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• 2011

This paper presents a wide tuning range, fine-resolution DCO (Digitally Controlled Oscillator) with an active inductor. In order to control the frequency of the DCO, the transconductance of the active inductor is tuned digitally. In addition, the DCO gain needs to be calibrated digitally to compensate for gain variations. To cover the wide tuning range, an automatic three-step coarse tuning scheme is proposed. The DCO total frequency tuning range is 1.4 GHz (2.1 GHz to 3.5 GHz), it is 58 % at 2.4 GHz. An effective frequency resolution is 0.14 kHz/LSB. The proposed DCO is implemented in 0.13 ${\mu}m$ CMOS process. The total power consumption is 6.6 mW from a 1.2 V supply voltage. The phase noise of the DCO output at 2.4 GHz is -120.67 dBc/Hz at 1 MHz offset.

• Proceedings of the Optical Society of Korea Conference
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• 1991.06a
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• pp.150-155
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• 1991

연소기체의 진단연구에 응용하기 위한 코헤런트 라만분광기를 설계·제작하여 성능을 조사하였다. 광원으로는 단일 종모드로 발진하는 Nd:YAG 레이저의 이차고조파와 색소 레이저를 이용하였다. Collinear 방법으로 상온의 질소기체 압력을 변화시키면서 분광 신호를 측정하였으며, 제작된 분광기 성능에 대하여 논의하였다.

• Electronics and Telecommunications Trends
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• v.21 no.5 s.101
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• pp.119-128
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• 2006

밴드구조 엔지니어링과 분자선 에피택셜 성장법에 의해 실현된 양자종속레이저는 유럽, 미국을 중심으로 활발한 연구가 진행되고 있으며, 눈부신 발전을 거듭해왔다. 최근, 중적외선 영역에서의 실온 연속 레이저 발진과 테라헤르츠 영역에서 파장이 약 $100\mum$를 넘는 레이저 발진이 실현되어 큰 주목을 끌고 있다. 본 고에서는 발광층 디자인을 중심으로 양자종속레이저의 원리 및 성능에 대하여 소개한 후, 이 분야에 있어서 지금까지 이루어진 기술적인 약진에 대하여 기술한다.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.334-337
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• 2003

GSM / DCS1800 / PCS 대역에서 사용 가능한 9.5mm x 6.5mm 크기의 트리플 밴드 초소형 전압제어 발진기를 설계하였다. 설계된 트리플 밴드 VCO는 GSM(880∼915MHz) 대역에서 7±3dBm의 출력전력, DCS1800 (1720∼1785MHz) 대역에서 8±3dBm의 출력전력, PCS(1720∼1780MHz) 대역에서 0±3dBm의 출력전력의 특성을 보인다. 위상 잡음의 특성은 -110dBc @100KHz 이하의 만족할만한 성능을 보인다.