Search | Korea Science

Park, U-Sung-;Park, Choon-Bae-
- Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
- /
- 1994.11a
- /
- pp.17-20
- /
- 1994
Electrical Chracteristics of ZnO doped with Al$_2$O$_3$were investigated using complexe impedence measurements. The electrical conductivity of ZnO samples increased whithin 0.5mol% of Al$_2$O$_3$ doping, but decreased abode 0.5mol%. The increase and decrease of electrical conductivity seem to be the effect of Al$_2$O$_3$ doner doping and increasement of the number of grain boundary ZnO, respectively.

이석현;이호준;황기웅
- The Transactions of the Korean Institute of Electrical Engineers
- /
- v.41 no.5
- /
- pp.492-501
- /
- 1992
In this paper, an ion analyzer is used in conjunction with a Langmuir probe to study the chracteristics of ECR plasma such as the ion temperature, ion current density and electron temperature as the operating pressure, ${\mu}$-wave power and axial position change, Silicon etching has been performed with RF-biasing and its etching chracteristics have been discussed in terms of the ion energy distribution function. The maximum value of ion current density appears in the range of 10S0-3T mbar and the broadening of ion energy distribution function increases as pressure increases. Therefore, as pressure decreases, anisotropy increases but selectivity to photoresist decreases.

Lee, Hyun-Jong;Kim, In-Sung;Min, Bok-Gi;Song, Jae-Sung
- Proceedings of the KIEE Conference
- /
- 2005.07b
- /
- pp.1506-1508
- /
- 2005
VCO(voltage controlled oscillator) using mobile communication device decides direct characteristics as parts that affect important in stable oscillation and distortion characteristics of system. VCO used 900 MHz band was designed by the transformation of Colpitts circuit form use ADS that consider Q-factor to minimize phase noise. VCO manufactured together evaluation board and voltage control oscillator to FR-4 PCB. VCO experimented chracteristics after control through resonance department tuning. In our research, the designed VCO has 15.5 dBm output level at the bias condition of 6V and 10mA and the operating frequency range of 917 MHz$\sim$937 MHz band. Phase noise is -98.28 dBc/Hz at 1 MHz frequency offset from the carrier.
PDF

Park, Chin-Hong
- Bulletin of the Korean Mathematical Society
- /
- v.32 no.2
- /
- pp.145-152
- /
- 1995
From now on, we assume that a ring R has an identity 1. We have the following Lemma from Park[2].
PDF