• Proceedings of the KIEE Conference
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 B
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• pp.318-320
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• 2000

This paper presents the develop-ment of electromagnetic wave detecting equipment for diagnosis of enclosed switchboard. High voltage power equipments are very important equipment of the key industries and the private enterprise power line accidents are national plans because of those set off casualties lose of power equipments and communication networks. Therefore the necessity of the development of detecting for power equipment diagnosis is demand for prevention of high voltage equipment accidents. This paper is the development of electromagnetic wave detecting equipment for diagnosis of high voltage equipment. This paper establishes the diagnosis method for high voltage power equipments, that secures original technique and possesses detecting technique for electromagnetic wave. By the study we developed electromagnetic wave detector and we applied this equipment application tests at the place constructed high voltage equipments.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제8권5호
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• pp.1000-1006
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• 2007

This paper presents a power detector circuit which monitors the transmitting power for the application in CDMA cell phones. The proposed power detector are composed of coupler for coupling output power and detector fur monitoring output power. The designed coupler has low loss characteristic because it adopts the stripline structure which consists of two ground planes at both sides of signal plane. The design frequency is 824-849MHz which is the Tx band fur CDMA mobile terminal, and the coupling factor of the stripline coupler is -20dB. A schottky barrier diode is adopted for detector design because of its high speed operation with minimized loss. The required impedance matching is performed to improve the linearity and sensitivity of output voltage at relatively low detector input level where the nonlinear characteristic of diode exists. The package parasitics as well as intrinsic diode model are considered for simulation of the detector. The predicted performances agree well with the measured results.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• 제16권5호
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• pp.494-500
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• 2005

In this paper, optical noise is reduced by a differential detector with an optical fiber coupler in an optical wireless system. An $1\times2$ optical fiber coupler divides the received optical signal by 2 equally, and connects them to the two photodiodes in a differential detector. The output voltage variation due to the abrupt change of optical noise distribution in space disappears because the two photodiodes effectively detect the optical signal at the same point. The signal to noise ratio in a differential detector with a fiber coupler was 8 dB higher than in a single photodiode with an optical filter.

• Journal of IKEEE
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• 제17권4호
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• pp.544-549
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• 2013

This paper describes a modified binary phase detector (Bang-Bang phase detector - BBPD) for jitter reduction in clock and data recovery (CDR) circuits. The proposed PD reduces ripples in the VCO control voltage resulting in reduced jitter for CDR circuits. A 2.5 Gbps CDR circuit with a proposed BBPD has been designed and verified using Dongbu $0.13{\mu}m$ CMOS technology. Simulation shows the CDR with proposed PD recovers data with peak-to-peak jitter of 10.96ps, rms jitter of 0.86ps, and consumes 16.9mW.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• 제11권4호
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• pp.39-52
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• 2000

A design of 2 stage S-DLVA(successive detector log video amplifier) was studied to detect wide dynamic radar pulse ranging from -70 ㏈m to 0㏈m. A basic design idea was focused on the linear detection in logarithmic scale of wide dynamic range radar pulses from nosie-like weak power of -70 ㏈m to relatively high power 0 ㏈m. It is highly formidable, since it requires high speed detection less than 10 nsec over the operating frequency ranges from 6 to 18 ㎓. A limiter diode, a tunnel diode and an L17-C were used as a protecting device, a detector diode and a log video amplifier in companion as a single stage detector to give voltage output proportional to the input power of about 35 ㏈ dynamic range. A protype of 2-stage DLVA having one more single stage detector was fabricated with a 32 ㏈ low noise amplifier and a 3 ㏈ hybrid coupler to provide total 70 ㏈ dynamic range detection. The logging characteristics were measured to have log slope of 25m.V/㏈ against 70 ㏈ logging range from -55 ㏈m to +15 ㏈m, the log linearity of within +/- 1.5 ㏈, and tangential sensitivity was at -63 ㏈m. The pulse dynamics of rise time and recovery time were measured as 50 nsec and 1.2 $\mu$sec, respectively. The reason might be due to the parasitic capacitances of packaged limiter, tunnel diode, and L17-C.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.366-369
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• 2002

At present, the study of direct digital X-ray detector and indirect digital X-ray detector proceed actively. But it needs high thickness and high voltage in selenium for high ionization rate. Therefore, we carried out the study of electric characteristics of a-Se with additive ratio of Iodine in drafting study for developing Hybrid X -ray Sensor for complementing direct digital X -ray detector and indirect digital X-ray detector in this paper. On this, there are formed Amorphous selenium multi-layers by sticking phosphor layer$(Gd_{2}O_{2}S(Eu^{2+}))$ using optical adhesives of EFIRON Co. Amorphous selenium multi-layers having dielectric layer(parylene) has characteristics of low dark-current, high X-ray sensitivity. So we can acquired a enhanced signal to noise ratio. We make Amorphous selenium multi-layers with $30{\mu}m$ thickness on glass.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 한국전기전자재료학회 2006년도 추계학술대회 논문집 광주전남지부
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• pp.87-90
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• 2006

Two SiC radiation detector samples were irradiated by Co-60 gamma rays. The irradiation was performed with dose rates of 5 kGy/hour and 15 kGy/hour for 8 hours, respectively. Metal/semiconductor contacts on the surface were fabricated by using a thermal evaporator in a high vacuum condition. The SiC detectors have metal contacts of Au(2000 ${\AA}$)/Ni(300 ${\AA}$) at Si-face and of Au(2000 ${\AA}$)/Ti(300 ${\AA}$) at C-face. I-V characteristics of the SiC semiconductor were measured by using the Keithley 4200-SCS parameter analyzer with voltage sources included. From the I-V curve, we analyzed the Schottky barrier heights(SBHs) on the basis of the thermionic emission theory. As a result, the 6H-SiC semiconductor showed- similar Schottky barrier heights independent to the dose rates of the irradiation with Co-60 gamma rays.

• Proceedings of the KIEE Conference
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1268-1270
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• 1995

A method using photoelectric effect of a single-mode optical fiber, with a 632.8nm He-Ne laser, has been developed for the simultaneous measurment of current and voltage. The Magnetic stress for the current and the piezoelectric effect for voltage are utilized. It is found that the detector output voltage is proportional to the square of the applied current and the frequency of the output is twice of that of the applied current.

• The Transactions of the Korean Institute of Electrical Engineers B
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• 제53권9호
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• pp.562-568
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• 2004

The frequency and phase angle of the utility voltage are important in many industrial systems. In the three-phase system, they can be easily known by using the utility voltage vector. However, in the case of single phase system, there are some difficulties in detecting the information of utility voltage. In conventional system, the zero-crossing detection method is widely used, but could not obtain the information of utility voltage instantaneously. In this paper, the new digital PLL control using virtual two phase detector is proposed with a detailed analysis of single-phase digital PLL control for utility connected systems. The experimental results under various utility conditions are presented and demonstrate an excellent phase tracking capability in the single-phase grid-connected operation.

• Proceedings of the KIEE Conference
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• 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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• pp.34-37
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• 2001

In this paper, we designed and implemented the 60W DC characteristic measurement system for semiconductor devices. The proposed system is composed of 2 SMU(Source and Measure Unit)s, 2 HPU(High power Unit)s, 2VSU(Voltage Source Unit)s, and 2 VMU(Voltage Measurement Unit)s. HPU can source/measure voltage from -200V to 200V and source/measure current from -3A to 3A within 60W. Experimental results show that the implemented system can measure the power devices such as power BJT, regulator IC, and voltage detector.