• 조명전기설비학회논문지
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• 제20권9호
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• pp.40-44
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• 2006

This study investigated a new tuneable bandpass filter based on coplanar waveguide coupled line structure, and using the varactor diode for tuning the center frequency of the filter. The filter was designed by a commercial simulator and had a tuning range of 180[MHz] from 0.95[GHz] to 1.13[GHz]. The filter acceptable values regarding the insertion loss was less than 3[dB] and its return loss greater than 12[dB]. The figure of merit of the implemented tuneable filter increased with the reverse bias voltage up to 14[V] on the varactor diode. The proposed filter has a promising future as it can be used in integration processes and in various materials as substrate.

• Journal of information and communication convergence engineering
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• 제8권3호
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• pp.263-266
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• 2010

In this paper, a novel defected ground structure (DGS) pattern with enhanced effective capacitance (varactor diode) and a hole in PCB center is presented. The increase in effective capacitance enables the new DGS pattern to achieve a lower resonance than the DGS pattern for the same etched square dimension. The hole in the center also can make resonator frequency lower with better characteristic. According to the tunable characteristic of varactor diode, the resonant frequencies can be tunable. Simulation results show that a lower resonance is achieved with active device, compared to a common DGS pattern.

• 한국전기전자재료학회논문지
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• 제16권12호
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• pp.1097-1102
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• 2003

In this paper, we used only PR as etching mask, while it used usually Cr/AU as etching mask, and in order to fabricate a photosensor has the increased sensitivity, we investigated on the sensitivity of general type and p-i-n type diode. we designed microchannel size width max 10um, min 5um depth max 10um, reservoir size max 100um, min 2mm. Fabrication of microfluidic devices in glass substrate by glass wet etching methods and glass to glass fusion bonding. The p-i-n diode has higher sensitivity than photodiode, Considering these results, we fabricated p-i-n diodes on the high resistive(4㏀$.$cm) wafer into rectangle and finger pattern and compared internal resistance of each pattern. The internal resistance of pin diode can be decreased by the application of finger pattern has parallel resistance structure from 571Ω to 393Ω.

• ETRI Journal
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• 제38권2호
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• pp.227-234
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• 2016

Herein, we demonstrate clipping distortion suppression of directly modulated multi-IF-over-fiber links using a simple shunt diode predistorter. The dynamic range of a directly modulated analog fiber optic link is limited by nonlinear distortions caused by laser-diode clipping. We investigate the link performance in the context of carrie-to-noise and distortion ratio (CNDR) and error vector magnitude (EVM) requirements when supporting LTE-A services. We also design an analog predistorter with a shunt-diode structure, and demonstrate experimentally that the predistorter has the ability to suppress clipping-induced third-order intermodulation distortions of the link by at most 14 dB. It also improves the CNDR and EVM of the 4-IF-multiplexed LTE-A carriers by 7 dB and 2.9%, respectively.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 하계학술대회 논문집
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• pp.350-353
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• 2002

High voltage SiC Schottky barrier diodes with field plate structure have been fabricated and characterized. N-type 4H-SiC wafer with an epilayer of ∼10$\^$15/㎤ doping level was used as a starting material. Various Schottky metals such as Ni, Pt, Ta, Ti were sputtered and thermally-evaporated on the low-doped epilayer. Ohmic contact was formed at the backside of the SiC wafer by annealing at 950$^{\circ}C$ for 90 sec in argon using rapid thermal annealer. Field oxide of 550${\AA}$ in thickness was formed by a wet oxidation process at l150$^{\circ}C$ for 3h and subsequently heat-treated at l150$^{\circ}C$ for 30 min in argon for improving oxide quality. The turn-on voltages of the Ni/4H-SiC Schottky diode was 1.6V which was much higher than those of Pt(1.0V), Ta(0.7V) and Ti(0.7). The voltage drop was measured at the current density of 100A/$\textrm{cm}^2$ showing 2.1V for Ni Schottky diode, 1.45V for Pt 1.35V, for Ta, and 1.25V for Ti, respectively. The maximum reverse breakdown voltage was measured 1100V in the file plated Schottky diodes with 101an thick epilayer.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.881-884
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• 2003

We propose a new pixel structure for Active Matrix OLED (AMOLED). The proposed pixel structure can display full color images by compensating threshold voltage (Vth) variation of driving TFTs. And we obtain an improved contrast ratio(C/R) of higher than 600:1

• ETRI Journal
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• 제25권3호
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• pp.149-155
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• 2003

A self-pulsating multisection distributed-feedback laser diode (DFB LD) can potentially realize all-optical clock extraction. This device generally consists of three sections, two DFB sections and one waveguide section. The most important variable in this device is detuning, which is the relative spectral position between the stop bands of two DFB sections. We fabricated a novel structure in which two gratings were located one over and one under the active layers. Each grating structure was independently defined in processing so that detuning, which is the prerequisite for self-pulsation, could be easily controlled. Observing various self-pulsating phenomena in these devices under several detuning conditions, we characterized the phenomena as dispersive Q-switching, mode beating, and self-mode-locking.

• ETRI Journal
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• 제28권1호
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• pp.84-86
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• 2006

This letter presents a small-sized, high-power single-pole double-throw (SPDT) switch with defected ground structure (DGS) for wireless broadband Internet application. To reduce the circuit size by using a slow-wave characteristic, the DGS is used for the quarter-wave (${\lambda}$/4) transmission line of the switch. To secure a high degree of isolation, the switch with DGS is composed of shunt-connected PIN diodes. It shows an insertion loss of 0.8 dB, an isolation of 50 dB or more, and power capability of at least 50 W at 2.3 GHz. The switch shows very similar performance to the conventional shunt-type switch, but the circuit size is reduced by about 50% simply with the use of DGS patterns.

• 대한전자공학회논문지TC
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• 제41권2호
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• pp.53-58
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• 2004

본 논문에서는 부성저항을 갖는 발진부의 귀환 경로에 PIN 다이오드를 이용한 스위칭 회로를 추가하여 저 위상잡음 듀얼밴드 전압제어 발진기를 구현하였다. PIN 다이오드에 전원이 인가되지 않았을 때는 5㎓ 대역에서 발진이 일어나고, 인가되었을 때는 1.8㎓ 대역에서 발진이 일어난다. VCO의 위상잡음을 향상시키기 위하여 공진기에 PBG(Photonic Bandgap)구조를 접지 면에 적용하였다. 5.25㎓에서 출력 전력은 -9.17㏈m, 위상잡음은 -102㏈c/㎐이고, 1.8㎓에서 출력 전력은 -5.17㏈m, 위상잡음은 -101㏈c/㎐이다.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2009년도 공동학술대회
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• pp.538-539
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• 2009

해양교통안전시설인 등대 불빛은 지금까지 백열전구를 사용한 필라멘트를 이용하여 열을 빛으로 바꾸는 광원을 사용하고 있으며, 점차적으로 저전력 소비 및 장수명의 장점을 가진 고휘도 LED(Light Emitting Diode)을 이용한 LED 도등, LED 등명기, LED 등대 표체 경관조명, LED로 만든 전등 국내 개발 등 차세대 광원 "발광다이오드"는 수년내에 시장을 평정할 것으로 전망된다.