• Journal of the Korea Institute of Information and Communication Engineering
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• v.17 no.11
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• pp.2479-2485
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• 2013

In this paper, we present a design for solid-state radar SSPA with sequential bias. We apply to variable extension pulse generator to eliminate signal distortion which is caused by bias rising/falling delay of power amplifier. There is an optimum impedance matching circuit to have high efficiency of GaN-power device by measuring microwave characteristics through load-pull method. The designed SSPA is consisted of pre-amplifier, drive-amplifier and main-amplifier as a three stages to apply for X-Band solid-state radar. Thereby we made a 200W SSPA which has output pulse maximum power shows 53.67dBm and its average power is 52.85dBm. The optimum design of transceiver module for solid-state pulse compression radar which is presented in this dissertation, it can be available to miniaturize and to improve the radar performances through additional research for digital radar from now on.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.05a
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• pp.811-814
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• 2015

There are many modern societies use the digital products in everyday life in the Middle, convenience, give him plenty of Bluetooth is one of the users. Bluetooth (IEEE 802.15.1) means equipment in the close range between the low-power wireless communication standard for the connection to use the technology. Currently, Bluetooth earphone, Bluetooth speaker, wearable mounted devices also used a lot because it takes people to exploit the benefits had been lifted and thereby increases your damage. So, reducing the damage the user's further research about the security technique that can stop completely. I am sure that many Bluetooth hacking techniques, a Bluetooth device firmware vulnerability within the stored data to allow the approach to attacking the BlueTooth Snarfing and want to analyze.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.3
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• pp.226-232
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• 2005

Recently, many nation have released standard such as IEC 61000-3-2 and IEEE 59, which impose a limit on the harmonic current drawn by equipment connected to AC line in order to prevent the distortion of an AC Line. Therefore, Plasma Display Panel(PDP) which is highlightened in digital display device also has the Power Factor Correction(PFC) circuit to meet the harmonic requirements. In PDP power module, the conventional boost converter is usually used for the PFC circuit. However, it comes serious thermal problem on it's bridge diode due to heat of PDP, and therefore the system stability is not guaranteed. In this paper, the bridgeless boost converter, which is used for PFC circuit of the PDP power module, is designed and verified the possibility of the application In a practical product in a view of efficiency, component count, temperature and etc.

• Journal of Power Electronics
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• v.17 no.1
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• pp.56-66
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• 2017

Fast and accurate fault detection is the primary step and one of the most important tasks in fault tolerant converters. In this paper, a fast and simple method is proposed to detect and diagnosis the faulty cell in a cascaded H-bridge multilevel inverter under a short circuit fault. In this method, the reference voltage is calculated using switching control pulses and DC-Link voltages. The comparison result of the output voltage and the reference voltage is used in conjunction with active cell pulses to detect the faulty cell. To achieve this goal, the cell which is active when the Fault signal turns to "0" is detected as the faulty cell. Furthermore, consideration of generating the active cell pulses is completely described. Since the main advantage of this method is its simplicity, it can be easily implemented in a programmable digital device. Experimental results obtained with an 11-level inverter prototype confirm the effectiveness of the proposed fault detection technique. In addition, they show that the diagnosis method is unaffected by variations of the modulation index.

• Convergence Security Journal
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• v.14 no.7
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• pp.91-99
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• 2014

NFC(Near Field Communication) is a wireless data exchange technology in 13.56MHz frequency band between devices. The NFC Forum defines the NDEF(NFC Data Exchange Format) exchanging data format between NFC devices and NFC Tags, the NFC RTD(Record Type Definition) defining the record types in the NDEF messages, the Smart Poster RTD in order to replace current paper posters and the Signature RTD to ensure the authenticity and integrity for NDEF records. But the previous smart poster authentication scheme have the weaknesses of using the PKI(Public Key Infrastructure) with certificates to verify the public key for the smart poster authentication and requiring the additional storage capacity of NFC tags for the authentication path. Therefore in this paper we propose a smart poster authentication scheme and implementation based on the authentication URL, a digital signature and a public key without the PKI and certificates for the smart poster authentication.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.11a
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• pp.456-459
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• 2004

Analog film/screen systems have been being changed to a digital x-ray imaging device using direct conversion materials. Photocoductors for a direct detection flat-panel imager require high x-ray absorption, ionization and charge collection, low leakage current and large area deposition. In this work, $HgI_2$ films with excellent properties for x-ray detector were deposited by screen printing method. The thickness of $HgI_2$ film was about $150\;{\mu}m$. The passivation layer is fabricated using a-Se and parlyene, the both fabrication $HgI_2$ film were compared for analyzing the leakage current reduction. We measured electrical properties-leakage current, photosensitivity, SNR though I-V measurement, As the result, $HgI_2$ film using a-Se passivation layer had the greater

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.2
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• pp.67-73
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• 2010

We have developed a millimeter-wave passive imaging system with reflector for detection of concealed objects. We have designed a millimeter-wave sensor, control device for reflector control, and a lens for focusing of millimeter-wave signal at center frequency of 94GHz. DC signal from millimeter-wave sensor output is filtered by low pass filter and amplified by video amplifier, and then converted into digital signal by using ADC/DAQ. This signal is image processed by computer, and it is possible to obtain millimeter-wave passive image with resolution of $18{\times}64$ pixel using the fabricated system. It is shown that we can obtain the image of men and concealed object with the system.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.2
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• pp.1-8
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• 2009

We designed an ADC that operated upto 500Msamples/sec based on proposed R-string folding block as well as second folding block. The upper four bits are processed in parallel by the R-string folding block while the lower four bits are processed in pipeline structured second folding block to supply digital output. To verify the circuit performance, we conducted HSPICE simulation and the average power consumption was only 1.34mW even when the circuit was running at its maximum sampling frequency. We further measured noise immunity by applying linear ramp signal to the input. The DNL was between -0.56*LSB and 0.49*LSB and the INL was between -0.93*LSB and 0.72*LSB. We used 0.35 microns MOSIS device parameters for this work.

• Journal of IKEEE
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• v.14 no.3
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• pp.190-198
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• 2010

This paper describes a auto focus piezo actuator driver IC for portable digital camera. The 80[V] DC voltage is generated by a DC-DC converter and supplied to power of piezo moving control circuit. The voltage of piezo actuator needs range -20[V] to 80[V] proportional to 1[Vp-p] input control voltages. The dimensions and number of external parts are minimized in order to get a smaller hardware size. IIC(Inter-IC) interface logic is designed for data interface and it makes debugging easy, test for mass productions. The power consumption is around 40[mW] with supply voltage of 3.6[V]. This device has been fabricated in a 0.6[um] double poly, triple metal 100[V] BCD MOS process and whole chip size is 1600*1500 [$um^2$].

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.41 no.4
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• pp.41-49
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• 2004

In this paper, a design and measurement method for FPGA embedded gigabit-transceiver is presented. Altera's Stratix GX device which is general purpose transceiver called GXB was used for implementing PCI Express transceiver. PCI Express is the generation high performance serial I/O bus used to interconnect peripheral devices. After GXB was set follow by PCI Express specifications, the design has been verified by timing simulation and implemented as hardware. We tested it as follow. First GXB internal digital and analog block test second GXB transmitter signal integrity test called Eye mask test, third GXB high-speed serial I/O buffer and on-chip termination test and the last GXB protocol test. This paper shows all the design and measurement procedure about FPGA embedded gigabit-transceiver.