• Title/Summary/Keyword: High-power output

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A Study on the characteristic analysis and optimization according to Ballast design of Induction Lamp (고출력 무전극램프의 점등회로 설계를 통한 특성분석 및 최적화에 관한 연구)

  • Chung, Young-Il;Jung, Dae-Chul;Park, Dae-Hee;Kim, Yong-Kab
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.10 no.1
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    • pp.31-37
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    • 2017
  • In this paper, we implemented for the development of a high output induction lamp system, which lamp design is optimized by gas type, mixing ratio, pressure and discharge tube size, amalgam type and mixing ratio, and characteristics of ferrite core in the lamp. It's the circuit design by improving the power factor and efficiency according to the driving method, which has analyzing the characteristics according to the waveform and frequency. Finally, luminaries design part for applying the optimal lighting system considering the surrounding environment, the characteristics of the lighting circuit for electrodeless lamp has analyzed and the improvement has been proceeded. In conclusion, the driving frequency has optimized at 135kHz with degrading $7{\sim}10^{\circ}C$ based on the results of the optical characteristics of the induction lamp on peak noise FET(Q3,Q4) damage.

V-band MIMIC Quadruple Subharmonic Mixer Using Cascode Harmonic Generator (Cascode 하모닉 발생기를 이용한 V-band MIMIC Quadruple Subharmonic 믹서)

  • An Dan;Lee Mun Kyo;Jin Jin Man;Go Du Hyun;Lee Sang Jin;Kim Sung Chan;Chae Yeon Sik;Park Hyung Moo;Shin Dong Hoon;Rhee Jin Koo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.5 s.335
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    • pp.55-60
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    • 2005
  • A V-band MIMIC quadruple subharmonic mixer is reported in this paper. The cascode harmonic generator is proposed for a high conversion gain. The proposed cascode harmonic generator is shown with a 4-th harmonic output characteristic that represents an average of 2.9 dB and a maximum of 4 dB higher than the conventional multiplier. The measured result of the subharmonic mixer has a conversion gain of 3_4 dB which a good conversion gain at a LO power of 13 dBm. Isolations of LO-to-IF and LO-to-RF were obtained -53.6 dB and -46.2 dB, respectively. The conversion gain of the subharmonic mixer in this study has a higher conversion gain compared with some other reports in millimeter-wave range.

Low Conversion Loss 94 GHz MHEMT MIMIC Resistive Mixer (낮은 변환손실 특성의 94 GHz MHEMT MIMIC Resistive 믹서)

  • An Dan;Lee Bok-Hyung;Lim Byeong-Ok;Lee Mun-Kyo;Oh Jung-Hun;Baek Yong-Hyun;Kim Sung-Chan;Park Jung-Dong;Shin Dong-Hoon;Park Hyung-Moo;Park Hyun-Chang;Kim Sam-Dong;Rhee Jin-Koo
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.5 s.335
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    • pp.61-68
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    • 2005
  • In this paper, low conversion loss 94 GHz MIMIC resistive mixer was designed and fabricated. The $0.1{\mu}m$ InGaAs/InAlAs/GaAs Metamorphic HEMT, which is applicable to MIMIC's, was fabricated. The DC characteristics of MHEMT are 665 mA/mm of drain current density, 691 mS/mm of maximum transconductance. The current gain cut-off frequency(fT) is 189 GHz and the maximum oscillation frequency(fmax) is 334 GHz. A 94 GHz resistive mixer was fabricated using $0.1{\mu}m$ MHEMT MIMIC process. From the measurement, the conversion loss of the 94 GHz resistive mixer was 8.2 dB at an LO power of 10 dBm. P1 dB(1 dB compression point) of input and output were 9 dBm and 0 dBm, respectively. LO-RF isolations of resistive mixer was obtained 15.6 dB at 94.03 GHz. We obtained in this study a lower conversion loss compared to some other resistive mixers in W-band frequencies.

Noise Whitening Decision Feedback Equalizer for SC-FDMA Receivers (SC-FDMA 수신기를 위한 잡음 백색화 판정궤환 등화기)

  • Lee, Su-Kyoung;Park, Yong-Hyun;Seo, Bo-Seok
    • Journal of Broadcast Engineering
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    • v.16 no.6
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    • pp.986-995
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    • 2011
  • In this paper, we propose a noise whitening decision feedback equalizer for single carrier frequency division multiple access (SC-FDMA) receivers. SC-FDMA has the same advantage as that of orthogonal frequency division multiple access (OFDMA) in which the multipath effect can be removed easily, and also solves the problem of high peak to average power ratio (PAPR) which is the main drawback of OFDMA. Although SC-FDMA is a single carrier transmission scheme, a simple frequency domain linear equalizer (FD-LE) can be implemented as in OFDMA, which can dramatically reduce the equalizer complexity. Moreover, some residual intersymbol interference in the output of the FD-LE can be further removed by an additional nonlinear decision feedback equalizer (DFE) in time domain, because the time domain signal is a digitally modulated symbol. In the conventional DFE, however, the noise is not white at the input of the decision device and correspondingly the decision is not optimum. In this paper, we propose an improved DFE scheme for SC-FDMA systems where a linear noise whitening filter is inserted before the decision device of the conventional DFE scheme. Through computer simulations, we compare the bit error rate performance of the proposed DFE scheme with the conventional equalizers.

Introduction of the representative mushroom cultivars and groundbreaking cultivation techniques in Korea

  • Jang, Kab-Yeul;Oh, Youn-Lee;Oh, Minji;Woo, Sung-I;Shin, Pyung-Gyun;Im, Ji-hoow;Kong, Won-Sik
    • Journal of Mushroom
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    • v.14 no.4
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    • pp.136-141
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    • 2016
  • The production scale of mushrooms in Korea is approximately 600 billion won, which is 1.6% of Korea's gross agricultural output. In Korea, ca. 190,000 tons of mushrooms are harvested annually. Although the numbers of mushroom farms and cultivators are constantly decreasing, total mushroom yields are increasing owing to large-scale cultivation facilities and automation. The recent expansion of the well-being trend has caused an increase in mushroom consumption in Korea: the annual per capita mushroom was 3.9 kg ('13), whichis a little higher than that in Europe. Thus, mushroom export, mainly Flammulina velutipes and Pleurotus ostreatus, has increased since the mid-2000s. Recently, however, it is slightly reduced. Nevertheless, Vietnam, Hong Kong, the United States, and the Netherlands continue to export mushrooms, and Korea has increased its export to Australia, Canada, Southeast Asia, etc. Canned Agaricus bisporus, the first export of the Korean mushroom industry, reached it speak sales in 1977-1978. When Korea initiated trade with China in 1980, the international prices of mushrooms fell sharply, leading to shrinkage of the domestic markets. Spurred by the high demand to develop substitute goods for A. bisporus, the oyster mushroom (P. ostreatus) gained attention since it seemed to suit the taste of Korean consumers. Although the log cultivation technique for oyster mushroom was developed in the early 1970s, it required a great deal of labor. Thus, we developed the shelf cultivation technique, which is easier to manage and allows for mass production. In this technique, the growing shelf is made mafrom fermented rice straw, whichis the only P. ostreatus medium in the world and isused only in South Korea. After then, the use of cotton wastes as an additional material of medium, the productivity. Currently, we are developing a standard cultivation technique and environmental control system that can stably produce mushrooms throughout the year. The increase of oyster mushroom production may boostthe domestic market and contribute to industrial development. In addition, oyster mushroom production technology played a role in forming the basis for the development of bottle cultivation, which made mass production. In particular, bottle cultivation using liquid spawn could allow for the export of F. velutipes and Pleurotus eryngii. In addition, the white varieties of F. velutipes were second developed in the world after Japan. We also developed the new A. bisporus cultivar 'Saeah', which is easy to grow in Korea. In hopes to advance the mushroom industry, we will continue to develop cultivars with international competitive power and to improve cultivation techniques.

Design of the Microwave Oscillator with the C type DGS Resonator (C형태의 DGS 공진기를 이용한 초고주파 발진기 설계)

  • Kim, Gi-Rae
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.8 no.4
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    • pp.243-248
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    • 2015
  • Since phase noise is one of the most important parameters in the design of microwave oscillators, several methods have been proposed to reduce the phase noise. These methods have focused on improving the quality factor of resonators, which result in low phase noise oscillators. Dielectric resonators have been widely used for low phase noise in microwave oscillators due to their high quality factor. However this cannot be used in MMIC oscillators because they have a 3D structure. In this paper, to overcome this problem a novel resonator using open ring type DGS is proposed for improvement of phase noise characteristics that is weak point of oscillator using planar type microstrip line resonator, and oscillator for 5.8GHz band is designed using proposed DGS resonator. The open ring type DGS resonator is composed of DGS cell etched on ground plane under $50{\Omega}$ microstrip line. At the fundamental frequency of 5.8GHz, 6.1dBm output power and -82.7 dBc@100kHz phase noise have been measured for oscillator with ring type DGS resonator. The phase noise characteristics of oscillator is improved about 96.5dB compared to one using the general ${\lambda}/4$ microstrip resonator.

Fabrication and analysis of $1.3\mum$ spot-size-converter integrated laser diodes (광모드변환기가 집적된 $1.3\mum$ SC-FP-LD 제작 및 특성 해석)

  • 심종인
    • Korean Journal of Optics and Photonics
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    • v.11 no.4
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    • pp.271-278
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    • 2000
  • We have fabricated and analyzed the lasing characteristics of 1.3$\mu\textrm{m}$ Spot-Size-Converter (SSC) integrated Fabry-Perot (FP) laser diodes, which are very promising light sources for optical subscriber networks. SSC-LDs has been developed by BIB (buttjoint-built-in) coupling and selective MOVPE growth. High-performances were achieved such as the slope efficiency from the SSC facet of 0.23-0.32 mW/mA, the full-width at the half maximum of the far-field pattern (FFP) of 9.5$^{\circ}$~12.3$^{\circ}$, the alignment tolerances of $\pm$2.3$\mu\textrm{m}$ and $\pm$2.5$\mu\textrm{m}$ within the extra-coupling loss of 1 dB for the vertical and parallel directions, respectively. These experimental results were compared to theoretical ones in order to clarify the operational problems and give a good design direction of the fabricated SSC-LDs. It was revealed that an asymmetric output power from the facets, an irrelevancy of FFP and the waveguide structure around SSC facet region, and a poor temperature characteristics were originated from the scattering in the BIB and SSC sections and SHB effect in the active section for the first time.t time.

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A $64\times64$ IRFPA CMOS Readout IC for Uncooled Thermal Imaging (비냉각 열상장비용 $64\times64$ IRFPA CMOS Readout IC)

  • 우회구;신경욱;송성해;박재우;윤동한;이상돈;윤태준;강대석;한석룡
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.36C no.5
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    • pp.27-37
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    • 1999
  • A CMOS ReadOut Integrated Circuit (ROlC) for InfraRed Focal Plane Array (IRFPA) detector is presented, which is a key component in uncooled thermal imaging systems. The ROIC reads out signals from $64\times64$ Barium Strontium Titanate (BST) infrared detector array, then outputs pixel signals sequentially after amplifying and noise filtering. Various design requirements and constraints have been considered including impedance matching, low noise, low power dissipation and small detector pitch. For impedance matching between detector and pre~amplifier, a new circuit based on MOS diode structure is devised, which can be easily implemented using standard CMOS process. Also, tunable low pass filter with single~pole is used to suppress high frequency noise. In additions, a clamping circuit is adopted to enhance the signal~to-noise ratio of the readout output signals. The $64\times64$ IRFPA ROIC is designed using $0.65-\mu\textrm{m}$ 2P3M (double poly, tripple metal) N~Well CMOS process. The core part of the chip contains 62,000 devices including transistors, capacitors and resistors on an area of about $6.3-mm\times6.7-mm$.

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A Design of Transceiver for 13.56MHz RFID Reader using the Peak Detector with Automatic Reference Voltage Generator (자동 기준전압 생성 피크 검출기를 이용한 13.56 MHz RFID 리더기용 송수신기 설계)

  • Kim, Ju-Seong;Min, Kyung-Jik;Nam, Chul;Hurh, Djyoung;Lee, Kang-Yun
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.47 no.3
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    • pp.28-34
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    • 2010
  • In this paper, the transceiver for RFID reader using 13.56MHz as a carrier frequency and meeting International Standard ISO 14443 type A, 14443 type B and 15693 is presented. The receiver is composed of envelope detector, VGA(Variable Gain Amplifier), filter, comparator to recovery the received signal. The proposed automatic reference voltage generator, positive peak detector, negative peak detector, and data slicer circuit can adjust the decision level of reference voltage over the received signal amplitudes. The transmitter is designed to drive high voltage and current to meet the 15693 specification. By using inductor loading circuit which can swing more than power supply and drive large current even under low impedance condition, it can control modulation rate from 30 percent to 5 percent, 100 perccnt and drive the output currents from 5 mA to 240 mA depending on standards. The 13.56 MHZ RFID reader is implemented in $0.18\;{\mu}m$ CM08 technology at 3.3V single supply. The chip area excluding pads is $1.5mm\;{\times}\;1.5mm$.

A study on characteristics of combustion and exhaust emissions on bio-diesel fuel in marine diesel generator engine (Low load centering) (선박용 디젤발전기에서 바이오연료의 연소 및 배기배출물 특성에 관한 연구 (저부하 영역 중심으로))

  • Cho, Sang-Gon
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.7
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    • pp.716-721
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    • 2015
  • As the severity of environmental pollution has increased, restrictions on air pollution have been strengthened. Stringent regulations have been imposed, not only on marine diesel engines but also on automotive and industrial power plants. Thus, biofuels have been directly applied in practical engines and used in training ships for basic research. Even though a high biofuel percentage cannot be used in a training ship engine for safety reasons, because this type of engine is larger than those used in institutional laboratories, the results will provide important basic information that will allow organizations to determine the status of a large output. Biodiesel fuel was studied to determine how it would affect the combustion characteristics and exhaust emissions of a marine diesel generator engine. The main results can be summarized as follows. Because the physical and chemical compositions of biofuels are similar to those of diesel fuel, it was found that their practical use was possible in a training ship. The specific fuel consumption and NOx increased, whereas a tendency was found for carbon monoxide and soot to decrease. In addition, no significant pressure change difference was found between the diesel fuel and biofuels.