• 한국산업융합학회 논문집
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• 제10권4호
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• pp.227-233
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• 2007

In case of design of a rectifier to supply high current, To select switching frequency of semiconductor switches affect absolutely the design of the LC filter value in an power conversion circuit. The conventional rectifier by using MOSFET is no use in high current equipments because of small drain-source current. To solve this problem, this paper proposes to design of high capacity rectifier by parallel driving of MOSFET in the single half bridge DC-DC converter. This method can be able to develop high current rectifier by distributed drain-source current. The proposed scheme is able to expect a decrease in size, weight and cost of production by decreasing the LC filter value and increasing maximumly the switching frequency. The validity of the proposed parallel driving strategy is verified through computer-aided simulations and experimental results.

• 전자공학회지
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• 제30권3호
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• pp.295-295
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• 2003

The advantages of using analogue optical networks for delivering radio signals from a central location to many remote antenna sites have been recognized. In a telecommnications context, radio signals may be for fixed radio access, cordless or mobile networks, but the same principles apply. By making use of the high bandwidth, low loss characteristics of optical fiber, all high frequency and signal processing functions can be performed centrally and signals can then be transported over the optical network directly at the carrier frequency. The remote sites then become very simple, requiring only optoelectronic conversion, filtering and linear amplification. This shifting of the complex functionality away from the remote site allow cheap, reliable, small and light-weight radio access points with low power consumption to be deployed. In this paper, we show that an electroabsorption modulation(EAM) may be used as a single component in such a radio access point, as a passive transceiver for small-sized cell(picocells).

• 전자공학회지
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• 제30권3호
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• pp.81-85
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• 2003

The advantages of using analogue optical networks for delivering radio signals from a central location to many remote antenna sites have been recognized. In a telecommnications context, radio signals may be for fixed radio access, cordless or mobile networks, but the same principles apply. By making use of the high bandwidth, low loss characteristics of optical fiber, all high frequency and signal processing functions can be performed centrally and signals can then be transported over the optical network directly at the carrier frequency. The remote sites then become very simple, requiring only optoelectronic conversion, filtering and linear amplification. This shifting of the complex functionality away from the remote site allow cheap, reliable, small and light-weight radio access points with low power consumption to be deployed. In this paper, we show that an electroabsorption modulation(EAM) may be used as a single component in such a radio access point, as a passive transceiver for small-sized cell(picocells).

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 F
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• pp.2712-2714
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• 1999

The small signal model for input series-output parallel connected converter system employing charge control together with input capacitor voltage feedback loop is developed. From the model developed, the effect of input capacitor voltage feedback loop to the system stability and outer loop compensator design is analyzed. Theoretical results and simulation show that input capacitor voltage feedback loop has no critical effects on the system stability, so the system can be reduced to a equivalent single module for the stability analysis and outer loop compensator design.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 추계종합학술대회 논문집(2)
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• pp.152-155
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• 2000

Oversampling modulators based on high-order sigma-delta modulation provide an effective means of achieving high-resolution A/D conversion in a VLSI technology. Because high-order noise shaping great]y reduces the quantization noise in the signal band. This paper introduces a third-order cascaded sigma-delta modulator that is stable for large input level. Modulator was simulated 3.3V single power supply voltage in 0.65$\mu\textrm{m}$ CMOS technology. It achieves 80㏈ SNR for a 20㎑ input signal bandwidth. A lock frequency is 3㎒ that is 80 oversampling ratio.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 추계종합학술대회 B
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• pp.612-614
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• 2008

Organic photovoltaic effects were studied in a device structure of ITO/CuPc/Al and ITO/CuPc/$C_{60}$/BCP/Al. A thickness of CuPc layer was varied from 10nm to 50nm, we have obtained that the optimum CuPc layer thickness is around 40nm from the analysis of the current density-voltage characteristics in CuPc single layer photovoltaic cell. From the thickness-dependent photovoltaic effects in CuPc/$C_{60}$ heterojunction devices, higher power conversion efficiency was obtained in ITO/20nm CuPc/40nm $C_{60}$/Al, which has a thickness ratio (CuPc:$C_{60}$) of 1:2 rather than 1:1 or 1:3. Light intensity on the device was measured by calibrated Si-photodiode and radiometer/photometer of International Light Inc(IL14004).

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.510-510
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• 2000

This paper introduces the design of BiCMOS latched comparator circuit for high-speed system application, which can be used in data conversion, instrumentation, communication system etc. By exploiting the advantage technology of the combination of both the bipolar transistor and the CMOS transistor devices. The comparator circuit includes an input stage that combines MOS sampling with a bipolar regenerative amplifier. The resistive load of conventional current-steering comparator is replaced by a load, which is made by a NMOS transistor. The advantage of design and PSPICE simulation of BiCMOS latched comparator are the circuit will obtain wide bandwidth with lowest power consumption at a single supply voltage. All the characteristics of the proposed BiCMOS latched comparator circuit is carried out by simulation program.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1286-1288
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• 1994

Methods are described for the design and fabrication of the sensor circuits on the polarographic oxygen sensing electrodes. The discussion includes: a method for the +5V single-supply driving for the sensor circuits, a method of low power comsumption for the front-end electronics. Typical polarograms for the commercial DO probes using this sensor circuits are presented. High accuracy of the I to V conversion using the circuits is verified.

• 한국자동차공학회논문집
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• 제12권6호
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• pp.80-89
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• 2004

In order to confront the increasing air pollution and the tightening emission restrictions, this research developed a diesel engine using DME, the advanced smoke-free alternative fuel. By numerical analysis, flow field, spray, and combustion phenomenon of the DME engine was presented. Using an experimental method, the configuration of the fuel supply system and operation/power performance was tested with the current plunger pump. Most emission performance, especially smoke performance was significantly improved. The possibility of conversion from the current diesel engine into the DME engine was affirmed in this research. However, it was found that the increase of engine RPM and fuel amount need to be properly adjusted through matching the characteristics of fuel and injector for further improvement.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.2067-2070
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• 2002

In this paper, a VLSI architecture for transform and quantization module, which consists of 2D-DCT, quantization, AC/DC prediction block, scan conversion, inverse quantization and 2D-IDCT, is presented. The architecture of the module is designed to handle a macroblock data within 1064 cycles and suitable for MPEG-4 video codec handling CIF image formats. Only single 1-D DCT/IDCT cores are used for the design instead of 2-D DCT/IDCT, respectively. 1-bit serial distributed arithmetic architecture is adopted for 1-D DCT/IDCT to reduce the hardware area in this architecture. As the result, the maximum utilization of hardware can be achieved, and power consumption can be minimized. The proposed design is operated on 27MHz clock. The experimental results show that the accuracy of DCT and IDCT meet the IEEE specification.