• Bulletin of the Korean Chemical Society
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• v.30 no.12
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• pp.3127-3130
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• 2009

• 한국초전도학회:학술대회논문집
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• v.15
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• pp.42-42
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• 2005

• ETRI Journal
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• v.27 no.1
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• pp.75-80
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• 2005

This paper addresses a fully-integrated low phase noise X-band oscillator fabricated using a carbon-doped InGaP heterojunction bipolar transistor (HBT) GaAs process with a cutoff frequency of 53.2 GHz and maximum oscillation frequency of 70 GHz. The oscillator circuit consists of a negative resistance generating circuit with a base inductor, a resonating emitter circuit with a microstrip line, and a buffering resistive collector circuit with a tuning diode. The oscillator exhibits 4.33 dBm output power and achieves -127.8 dBc/Hz phase noise at 100 kHz away from a 10.39 GHz oscillating frequency, which benchmarks the lowest reported phase noise achieved for a monolithic X-band oscillator. The oscillator draws a 36 mA current from a 6.19 V supply with 47.1 MHz of frequency tuning range using a 4 V change. It occupies a $0.8mm{\times}0.8mm$ die area.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.12a
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• pp.123-123
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• 2003

• The Korean Journal of Quaternary Research
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• v.18 no.2 s.23
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• pp.51-55
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• 2004

• The Korean Journal of Quaternary Research
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• v.21 no.2
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• pp.25-27
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• 2007

• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.485-488
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• 2007

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.911-912
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• 2005

• Proceedings of the Korean Magnestics Society Conference
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• 2005.12a
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• pp.46-46
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• 2005

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3407-3412
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• 2012

The Ti incorporation at Fe-site in the double perovskite lattice of $Sr_2FeNbO_6$ (SFNO) system is studied. The Ti concentration optimization yielded an efficient photocatalyst. At an optimum composition of Ti as x = 0.07 in $Sr_2Fe_{1-x}Ti_xNbO_6$, the photocatalyst exhibited 2 times the quantum yield for photolysis of $H_2O$ in presence of $CH_3OH$, than its undoped counterpart under visible light (${\lambda}{\geq}420nm$). Heavily Ti-doped $Sr_2Fe_{1-x}Ti_xNbO_6$ lattice exhibited poor photochemical properties due to the existence of constituent impurity phases as observed in the structural characterization, as well as deteriorated optical absorption. The higher electron-density acquired by n-type doping seem to be responsible for the more efficient charge separation in $Sr_2Fe_{1-x}Ti_xNbO_6$ (0.05 < x < 0.4) and thus consequently displays higher photocatalytic activity. The Ti incorporated structure also found to yield stable photocatalyst.