• The Journal of Korean Institute of Communications and Information Sciences
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• v.29 no.4A
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• pp.415-422
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• 2004

DSRC provides high speed radio link between Road Side Equipment and On-Board Equipment within the narrow communication area. In this paper, a 5.8 GHz down-conversion mixer for DSRC communication system was designed and fabricated using 0.8 ${\mu}{\textrm}{m}$ SiGe HBT process technology and RF/LO matching circuits, RF/LO input balun circuits, and If output balun circuit were all integrated on chip. The chip size of fabricated mixer was 1.9 mm${\times}$1.3 mm and the measured performance was 7.5 ㏈ conversion gain, －2.5 ㏈m input IP3, 46 ㏈ LO to RF isolation, 56 ㏈ LO to IF isolation, current consumption of 21 mA for 3.0 V supply voltage.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.30 no.4A
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• pp.350-357
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• 2005

DSRC provides high speed radio link between Road Side Equipment and On-Board Equipment within the narrow communication area. In this paper, a 5.8 GHz up-conversion mixer for DSRC communication system was designed and fabricated using 0.8 m SiGe HBT process technology and IF/LO/RF matching circuits, IF/LO input balun circuits, and RP output balun circuit were all integrated on chip. The chip size of fabricated mixer was $2.7mm\times1.6mm$ and the measured performance was 3.5 dB conversion gain, -12.5 dBm output IP3, 42 dB LO to If isolation, 38 dB LO to RF isolation, current consumption of 29 mA for 3.0 V supply voltage.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.37 no.3
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• pp.307-313
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• 2009

In general, pyroshock is generated from the actuation of separation devices for several stage, fairing, and satellite separation in the flight of a launch vehicle. During these events, transient vibration phenomenon called pyroshock, which shows large acceleration in the high frequency range, occurs and it can result in the malfunction of electronic components which is equipped inside the launch vehicle or satellite. In this paper, mesh washer isolators made out of SMA were introduced for the isolation of pyroshock. One type of isolator primarily used pseudoelastic characteristics of SMA and the other type of isolator used shape memory effect of SMA. For the study of basic load-displacement relationship of each SMA isolator, compressive loading tests were performed and the results showed the capability of the isolator itself. Pyroshock isolation tests were followed and verified the outstanding isolation performance of isolator. In addition, random vibration tests were also performed and checked the dynamic characteristics of each SMA isolator.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.27-32
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• 2019

This study describes the design and implementation of a simulated signal generator to demonstrate the performance of VHF band radar for the detection of small targets in RCS(Radar Cross Section). The transmission and reception antenna beam widths used in the simulated signal generating apparatus may be large, which may cause problems in the degree of isolation. Interference signal immunity and isolation characteristics are improved by considering operating conditions of VHF radar to solve isolation of antennas. Simulated signal generator performs the following: VHF radar transmission and reception correction, simulation signal generation, target Doppler, RCS and distance simulation, remote control, and GPS clock synchronization function. After the fabrication of the simulated signal generator, the main characteristics, such as the output characteristics and the reflection signal simulations, were tested. When the microwave radar assembly is completed in the future, it will be utilized for the performance evaluation of VHF radar.

• Journal of IKEEE
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• v.27 no.4
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• pp.567-572
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• 2023

In this paper, the breakdown voltage of Pi-LDMOS (Partial isolation lateral double diffused metal oxide semiconductor) was analyzed by simulation. Breakdown voltage variation is investigated under various settings of Parial buied oxide(P-BOX) parameters(length, thickness, location) and their mechanism is specified. In addition, the change in on-resistance in the breakdown voltage and trade-off relationship was analyzed according to the change in the P-BOX parameter, and the Figure-of-merit(FOM) was calculated and compared. In proposed structure, Lbox=5 ㎛, tbox=2 ㎛, and Lbc=2 ㎛ showed the highest breakdown voltage of 138V, and Lbox=5 ㎛, tbox=1.6 ㎛, and Lbc=2 ㎛ showed the highest FOM. Compared to conventional LDMOS, the breakdown voltage is 123% and FOM is 3.89 times improved. Therefore, Pi-LDMOS has a high breakdown voltage and FOM, which can contribute to the improvement of the stable operating range of the Power IC.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.6
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• pp.223-229
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• 2023

This papart proposes single pole double throw (SPDT) switch with six-stage radial stub resonators in the 3.6~4.0 GHz band. The switch was simulated using ADS (Advanced Design Software), a design tool for the wireless communication circuits, and evaluated on a pcb substrate. The measurement results of the radial SPDT switch showed an average 90 dB isolation, and 1.5 dB insertion loss. This isolation characteristic was 20 dB superior to higher than those laboratory or commercial products reported thus far. The proposed SPDT switch is applicable to multi-band RF front-end systems, such as WiMAX, LTE/5G, Wi-Fi, and HyperLAN.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.182-184
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• 2009

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2009.10a
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• pp.696-697
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• 2009

• Bulletin of the Korean Chemical Society
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• v.35 no.9
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• pp.2867-2869
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• 2014

• 한국약용작물학회:학술대회논문집
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• 2007.11a
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• pp.319.1-319.1
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• 2007