• 베이커리
• /
• no.8 s.409
• /
• pp.30-35
• /
• 2002

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.20 no.1
• /
• pp.117-122
• /
• 2016

In this paper, we propose 24-GHz CMOS radio frequency (RF) power amplifier for short-range automotive collision avoidance radars. This circuit contains common source stage with inter-stages conjugate matching circuit as a class-A mode amplifier. The proposed circuit is designed using TSMC $0.13-{\mu}m$ mixed signal/RF CMOS process ($f_T/f_{MAX}=120/140GHz$). It operates at the supply voltage of 2V, and it is designed to have high power gain, low insertion loss and low noise figure in the low supply voltage. To reduce total chip area, the circuit used transmission lines instead of the bulky real inductor. The designed CMOS power amplifier showed the smallest chip size of $0.1mm^2$, the lowest power consumption of 40mW, the highest power gain of 26.5dB, the highest saturated output power of 19.2dBm and the highest maximum power-added efficiency of 17.2% as compared to recently reported results.

• Resources Recycling
• /
• v.15 no.2 s.70
• /
• pp.37-44
• /
• 2006

The total amount of graphite reserves in Korea is about 260 thousand tons. Graphite larks international competitiveness it is mined in only few mines, but recently the demand of portable electronic has increased. Therefore a research for manufacturing domestic high purity graphite is necessary because all of high purity graphite used electrode of 2nd batter depends on expensive importation. A preprocessing level for producing high purity graphite, flotation was conducted using microbubble column machine. In this research $D_{50}=10.314{\mu}m$ sample was used which was produced after grinding 29.50% F.C. primary crushing sample($D_{50}=69.393{\mu}m$) for 20 minutes through attrition mill. As a result using this sample, product above 95% F.C. with recovery over 90% was obtained with only after first stage process through the microbubble column.

• 한국해양학회지
• /
• v.29 no.3
• /
• pp.258-268
• /
• 1994

Nitrogenous new production and regenerated production were measured in the southern part of the Yellow Sea (Hwanghae) using a stable isotope /SUP 15/N nitrate and ammonia between April 25∼30, 1993. Nitrogen production varied between 155 and 688 mg N m/SUP -2/ d/SUP -1/, which belongs to meso to eutrophic area values. This is equivalent to 881∼3909 mg C m/SUP -2/ d/SUP -1/, assuming the Redfield ratio for C:N of 5.7:1 (by weight). the f0ratio which is the fraction of new production from primary production, varied between 0.12 and 0.26, indicating that 74 to 88% of primary production was supported by the regeneration of nutrients within the euphoric zone. This low f0ratio is the characteristics of the oligo- to mesotrophic area. Contrary to the expected, the ambient nutrient concentration was not an important factor for controlling productivity in this area during the study period. The difference in productivity among stations was mainly due to the variations in phytoplankton biomass in different water masses.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.43 no.4 s.346
• /
• pp.16-22
• /
• 2006

Gigabit transimpedance amplifiers are realihzed in submicron CMOS technologies for Gigabit Ethernet applications. The regulated cascode technique is exploited to enhance the bandwidth and noise performance simultaneously so that it can isolate the large input parasitic capacitance including photodiode capacitance from the determination of the bandwidth. The 1.25Gb/s TIA implemented in a 0.6um CMOS technology shows the measured results of 58dBohm transimpedance gain, 950MHz bandwidth for a 0.5pF photodiode capacitance, 6.3pA/sqrt(Hz) average noise current spectral density, and 85mW power dissipation from a single 5V supply. In addition, a 10Gb/s TIA is realized in a 0.18um CMOS incorporating the RGC input and the inductive peaking techniques. It provides 59.4dBohm transimpedance gain, 8GHz bandwidth for a 0.25pF photodiode capacitance, 20pA/sqrt(Hz) noise current spectral density, and 14mW power consumption for a single 1.8V supply.

• Korean journal of applied entomology
• /
• v.32 no.4
• /
• pp.382-388
• /
• 1993

Five nematophagous fungi, Arthrobotrys arthrobotryoides, A. conoides, A. oligospora, Dactylella lobata and Fusarium oxysporum were evaluated for nematicidal effect on Meloidogyne hapla in greenhouse. Treatment of nematophagous fungi reduced the root galling by M. hapla and increased red-pepper growth in naturally infested pot soil. Number of galling were significantly less inall pots in 4 different inoculum densities of 5 nematophagous fungi compared to untreated plots. Especially, treatment of F. oxysprum resutled significant reduction of root gall of red-pepper. The increased shoot growth was significantly higher in pretreated plots by A. arthrobotryoides, A. conoides, A. oligospora, D. lobata and F. oxysporum at inoculum concentration of 1:100 but other treatments were not significantly increased shoot growth. Two promising fungi, D. lobata and F. oxysporum were selected in greenhouse test and in vitro results of previously experiment and applied to field plot naturally infested by M. hapla serverely. Number of galls were remarkably fewer in plots treated with D. lobata and F. oxysporum at either 1:70 or 1:100 concentration compared to the untreated plots. The shoot growth of red-pepper was increased strikingly in the plots following the red-pepper was increased strikingly in the plots following the treatment of both fungus than greenhouse test.

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.227-228
• /
• 2006

In this paper, we introduce the design and fabrication of 60 GHz low noise amplifier MMIC for IEEE802.15.3c WPAN system. The 60 GHz LNA was designed using ETRI's $0.12{\mu}m$ PHEMT process. The PHEMT shows a peak transconductance ($G_{m,peak}$) of 500 mS/mm, a threshold voltage of -1.2 V, and a drain saturation current of 49 mA for 2 fingers and $100{\mu}m$ total gate width (2f100) at $V_{ds}$=2 V. The RF characteristics of the PHEMT show a cutoff frequency, $f_T$, of 97 GHz, and a maximum oscillation frequency, $f_{max}$, of 166 GHz. The performances of the fabricated 60 GHz LNA MMIC are operating frequency of $60.5{\sim}62.0\;GHz$, small signal gain ($S_{21}$) of $17.4{\sim}18.1\;dB$, gain flatness of 0.7 dB, an input reflection coefficient ($S_{11}$) of $-14{\sim}-3\;dB$, output reflection coefficient ($S_{22}$) of $-11{\sim}-5\;dB$ and noise figure (NF) of 4.5 dB at 60.75 GHz. The chip size of the amplifier MMIC was $3.8{\times}1.4\;mm^2$.

• Proceedings of the IEEK Conference
• /
• 2006.06a
• /
• pp.623-624
• /
• 2006

In this paper, we introduce the design and fabrication of V-band power amplifier MMIC with excellent gain-flatness for IEEE 802.15.3c WPAN system. The V-band power amplifier was designed using ETRI' $0.12{\mu}m$ PHEMT process. The PHEMT shows a peak transconductance ($G_{m,peak}$) of 500 mS/mm, a threshold voltage of -1.2 V, and a drain saturation current of 49 mA for 2 fingers and $100{\mu}m$ total gate width (2f100) at $V_{ds}$=2 V. The RF characteristics of the PHEMT show a cutoff frequency, $f_T$, of 97 GHz, and a maximum oscillation frequency, $f_{max}$, of 166 GHz. The gains of the each stages of the amplifier were modified to have broadband characteristics of input/output matching for first and fourth stages and get more gains of edge regions of operating frequency range for second and third stages in order to make the gain-flatness of the amplifier excellently for wide band. The performances of the fabricated 60 GHz power amplifier MMIC are operating frequency of $56.25{\sim}62.25\;GHz$, bandwidth of 6 GHz, small signal gain ($S_{21}$) of $16.5{\sim}17.2\;dB$, gain flatness of 0.7 dB, an input reflection coefficient ($S_{11}$) of $-16{\sim}-9\;dB$, output reflection coefficient ($S_{22}$) of $-16{\sim}-4\;dB$ and output power ($P_{out}$) of 13 dBm. The chip size of the amplifier MMIC was $3.7{\times}1.4mm^2$.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1997.04a
• /
• pp.42-47
• /
• 1997

In this study, the drawing characteristics of circular drawbead are examined with the plane strain elastic-plastic FE Method by varying the process variables such as friction coefficient, drawbead radius, and closing depth. Numerical analysis are carried out by 2-D elastic-plastic F.E.M. The results are compared with the existing experimental results about the drawing force, the die clamping force, and the strain distribution of upper and lower sheet faces

• The Korean Journal of Ceramics
• /
• v.4 no.3
• /
• pp.204-206
• /
• 1998

The Gibbs free energy of formation of $BaThO_3$ from elemental oxides has been measured at temperatures between 853 and 903 K using a $CaF_2$ solid electrolyte galvanic cell. The galvanic cell consisted of Pt, $O_2, CaO+CaF_2 \parallel CaF_2 \parallelBaThO_3+ThO_2+BaF_2, O_2$, Pt EMF gave the standard Gibbs free energy for the reaction $CaF_2+BaThO_3=CaO+BaF_2+ThO_3$ as $\DeltaG^o$,/TEX>=124111.031-117.597 T(J/mol).