• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권3호
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• pp.144-148
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• 2001

For the purpose of developing capacitive humidity sensor having interdigit electrodes, interdigit electrode was modeled and simulated to obtain capacitance and sensitivity as a function of geometric parameters like the structural gap and thichness. For the development of ASIC, switched capacitor signal conditioning circuits for capacitive humidity sensor were designed and simulated by cadence using 0.25um CMOS process parameters. The signal conditioning circuits are composed of amplifier for voltage gain control, and clock generator for sensor driving and switch control The characteristics of the fabricated sensors are; 1) sensitivity is 9fF/%R.H., 2) temperature coefficient of offset(TCO) is 0.4%R.H./$^{\circ}C$, 3) nonlinearity is 1.2%FS, 4) hysteresis is 1.5%FS in humidity range of 3%R.H. ${\sim}$ 98%R.H.. The response time is 50 seconds in adsorption and 70 seconds in desorption. Fabricated process used in this capacitive humidity sensor having interdigit electrode are just as similar as conventional IC process technology. Therefore this can be easily mass produced with low cost, simple circuit and utilized in many applications for both industrial and environmental measurement and control system, such as monitoring system of environment, automobile, displayer, IC process room, and laboratory etc..

• 한국콘텐츠학회논문지
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• 제9권12호
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• pp.566-571
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• 2009

본 논문에서는 마이크로스트립 전송선을 이용하여 필터를 구현할 때 고조파 대역에서 나타나는 불요 공진모드 특성을 제거하도록 DCRLH 메타셀을 헤어핀 공진기와 결합하여 기본 통과대역 신호만을 전달하는 마이크로스트립 대역통과 필터를 설계하고 제작하였다. 대역통과 필터는 불요 고조파 통과특성을 제거하기 위한 DCRLH 메타셀 전송선로와 통과대역 신호를 잘 전달하기 위한 CCRLH 헤어핀 공진기로 구성하였다. DCRLH 성질을 갖는 인터디짓 메타셀(Interdigit Meta-cell)은 필터회로의 입력단과 출력단에 병렬로 삽입하였고, CCRLH 대역통과 성질을 갖는 헤어핀공진기(Hairpin Resonator)는 두개의 DCRLH 메타셀 사이에 설치하였다. 이렇게 구성함으로써 저지대역에서 나타나는 불요고조파신호를 억제시킬 수 있었고, 필터의 대역통과 성능을 개선할 수 있었다. WCDMA 이동통신과 WiBro 무선 인터넷 통신을 동시에 수행할 목적으로 제작된 마이크로스트립 대역통과 필터는 1.91GHz~2.41GHz의 통과대역에서 삽입손실은 0.2dB로 나타났고, 3GHz~7.5GHz의 저지대역에서 감쇄특성은 -30dB 이하로 양호한 성능을 나타내었다.

• 조명전기설비학회논문지
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• 제19권4호
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• pp.79-84
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• 2005

본 논문은 액중 이온교환수 발생장치 내에 양${\cdot}$음이온교환격막을 중심으로 불평등전계를 형성할 수 있는 사선빗살형 전극을 설치하였다. 그리고 정극성과 부극성의 펄스전압을 인가하여 펄스전압의 극성변화에 의한 산화환원전위 변화가 이온교환수 발생장치 내에서 발생된 용존산소량에 미치는 영향을 비교 검토하였다. 실험결과, 이온교환수 발생장치 내에 인가된 펄스전압의 극성변화와 전기비저항의 차에 의한 산화환원전위 및 용존산소농도 변화를 관찰할 수 있었다. 그리고 인가된 펄스전압의 극성변화와 전기 비저항 차에 의한 전위변화가 용존산소농도를 증가시켜 액중에서 고농도의 이온들을 생성시킴을 알 수 있었다.

• ETRI Journal
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• 제9권3호
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• pp.74-85
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• 1987

본 논문은 PARCOR형 DTMF신호 수신방식을 이용하는 대역내 신호방식에 관하여 논한다. PARCOR 계수의 움직임에 관한 관찰 및 분석을 통하여 제안된 수신기의 성능평가, 즉 음성면역, 잡음면역 및 누화에 대한 면역 성능을 평가하고 이에 따른 수신 알고리즘 설계의 예를 제시한다.

• 센서학회지
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• 제21권5호
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• pp.345-351
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• 2012

Biomimetic terpene sensors which have high sensitivity and stability have been fabricated using moleculary imprinted polymer (MIP) technology. Since it is impossible to make a resistive type sensor due to the high resistance of MIP, we improved the sensor by adding conductive polymers. We investigated the sensitivity of resistive type sensors with nano particles depending on the amount of conductive polymers. The MIP membrane contained the methacrylic acid as functional monomer and ethylene glycol dimethacrylate as cross linker, which formed specific cavities originated by the target terpene molecules. The mixture of MIP and the conductive polymer was coated on the patterns of interdigit electrodes on the alumina substrate. The fabricated sensors showed their highest specific sensitivities exposed to 500 ppm target gases : limonene 0.055 at 40% of amount of conductive polymers and geraniol $5.84{\times}10^{-4}$ at 20% of amount of conductive polymers. In conclusion, we found that the terpene sensors are affected by the target molecules, functional monomers and the conductive polymers.

• 한국정보통신학회논문지
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• 제4권4호
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• pp.825-834
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• 2000

본 논문에서는 비아-홀 접지를 고려한 K-대역 인터디지트 대역통과필터를 설계하였다. 중심 주파수가 19.6GHz에서 25~30%대역만을 통과시키기 위해 6차 인터디지트 대역통과 필터를 마이크로 스트립라인으로 구성하였으며 비아-흘의 수에 따른 필터의 특성을 분석하였다. 비아-흘 접지와 인터디지트 대역통과필터는 설계 최적화 과정을 통하여 통과대역에서 중심주파수와 대역폭관계를 만족시킬 수 있었으며 실제 제작후 측정결과 중심주파수는 19.150Hz 삽입손실은 -4.IdB, 반사계수는 -16.7dB로 비아-홀 접지의 영향을 고려한 설계가 이루어짐을 증명하였다.

• 한국임상수의학회지
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• 제28권1호
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• pp.163-172
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• 2011

Subcutaneous foreign body causes recurrent problems such as chronic soft tissue swelling and discharge. Wooden foreign body is one of the most common foreign bodies found in subcutaneous region including face, interdigit, and thoracic or abdominal area. This report demonstrated three dogs with wooden foreign body located in subcutaneous region of thoracic wall, abdominal wall and upper eyelid, respectively. Three dogs showed prominent soft tissue swelling adjacent the foreign body. A sinus or drainage tract was developed in two of these dogs. Ultrasonography revealed that hyperechoic linear structure accompanied acoustic shadow in all dogs, and which was diagnosed as a subcutaneous foreign body. Anechoic or hyperechoic fluid and hypoechoic tissue circumscribed the foreign body. A subcutaneous foreign body in case 3 was removed by clamp under ultrasound-guide with sedation. Sinography was performed in case 1 and clarified that the wooden foreign body did not perforate the thoracic wall and there was no direct communication into thoracic cavity. Ultrasonography and sinography can be used to identify the subcutaneous foreign body and evaluate the inflammatory reaction and relationship between foreign body and adjacent structures.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2003년도 하계학술대회 논문집 Vol.4 No.2
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• pp.942-945
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• 2003

Nerve gas sensor based on tin oxide was fabricated and its characteristics were examined. Target gas was dimethylmethylphosphonate($C_3H_9O_3P$, DMMP) that is simulant gas of nerve gas. Sensing material was $SnO_2$ added ${\alpha}-Al_2O_3$ with $4{\sim}20wt.%$ and was physically mixed. And then it was deposited by screen printing method on alumina substrate. Sensor device was consisted of sensing electrode with interdigit(IDT) type in front and heater in back side. Total size of device was $7{\times}10{\times}0.6mm^3$. Crystallite size of fabricated $SnO_2$ were characterized by X-ray diffraction(XRD, Rigaku) and morphology of the $SnO_2$ powders was observed by a scanning electron microscope(SEM, Hitachi). Fabricated sensor was measured as flow type and sensor resistance change was monitored real time using LabVIEW program. The best conditions as added $Al_2O_3$ amounts and operating temperature changes were 4wt.% and $300^{\circ}C$ in DMMP 0.5ppm, respectively. The sensitivity was over 75%. Response and recovery times were about 1 and 3 min., respectively. Repetition measurement was very good with ${\pm}3%$ in full scale.

• 센서학회지
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• 제13권3호
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• pp.218-223
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• 2004

Thin film gas sensor based on tin oxide was fabricated and its characteristics were examined. Target gas is acetonitrile ($CH_{3}CN$) that is simulant gas of blood agent gas. Sensing materials are $SnO_{2}$, $SnO_{2}$/Pt, and (Sn/Pt)oxidation with thickness from $1000{\AA}$ to $3000{\AA}$. Sensor was consisted of sensing electrode with interdigit (IDT) type in front side and a heater in back side. Its dimension was $7{\times}10{\times}0.6mm^{3}$. Fabricated sensor was measured as flow type and monitored real time using PC. The optimal sensing material for $CH_{3}CN$ was {Sn($3000{\AA}$)/Pt($30{\AA}$)}oxidation and its sensitivity and operating temperature were 30%, $300^{\circ}C$ in $CH_{3}CN$ 3 ppm.

• 한국전기전자재료학회논문지
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• 제16권12S호
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• pp.1217-1223
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• 2003

Nerve gas sensor based on tin oxide was fabricated and its characteristics were examined. Target gas is dimethyl methyl phosphonate(C$_3$ $H_{9}$ $O_3$P, DMMP) that is simulant gas of nerve gas. Sensing materials were Sn $O_2$ added a-Al$_2$ $O_3$ with 0∼20wt.% and were physically mixed each material. They were deposited by screen printing method on alumina substrate. The sensor device was consisted of sensing electrode with interdigit(IDT) type in front and a heater in back side. Total size of device was 7${\times}$10${\times}$0.6㎣. Crystallite size & phase identification and morphology of fabricated Sn $O_2$ powders were analyzed by X-ray diffraction and by a scanning electron microscope, respectively. Fabricated sensor was measured as flow type and resistance change of sensing material was monitored as real time using LabVIEW program. The best sensitivity was 75% at adding 4wt.% $\alpha$-Al$_2$ $O_3$, operating temperature 30$0^{\circ}C$ to DMMP 0.5ppm. Response and recovery time were about 1 and 3min., respectively. Repetition measurement was very good with $\pm$3％ in full scale.TEX>$\pm$3％ in full scale.