• Transactions on Electrical and Electronic Materials
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• v.14 no.1
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• pp.28-31
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• 2013

A volcano shaped gated Si-FEA (silicon field emitter array) was simply fabricated using sputtering as a gate electrode deposition and lift-off for the removal of the oxide mask, respectively. Due to the limited step coverage of well-controlled sputtering and the high aspect ratio in Si dry etch caused by high RF power, it was possible to obtain Si FEAs with a stable volcano shaped gate structure and to realize the restriction of gate leakage current in field emission characteristics. For 100 tip arrays and 625 tip arrays, gate leakage currents were restricted to less than 1% of the anode current in spite of the volcano-shaped gate structure. It was also possible to keep the emitters stable without any failure between the Si cathode and gate electrode in field emission for a long time.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.10
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• pp.1461-1470
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• 2012

This paper reports the contamination performance of transmission line porcelain insulators tested under five different contaminant conditions - clean and ESDD (equivalent salt deposit density) level (A, B, C, and D) through measurement of their leakage current under drop of potential method. To estimate the contamination for transmission line porcelain insulators, leakage current waveform and its maximum value were measured under step-up power test. In the clean insulators test, % distortion factors decreased with increasing step-up power, and as the ESDD level increased, some characteristics such as frequency analysis, harmonics and % distortion facotor could be used for contamination diagnosis of the transmission line porcelain insulators.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.303-306
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• 2005

This paper presents the frequency-dependent characteristics of leakage currents flowing through ZnO surge arrester block. The leakage current-voltage (I-V) characteristic curves of the commercial ZnO surge arrester blocks were measured. The resistive leakage current was found to increase with increasing frequency in the low conduction region. The capacitance of ZnO block was independent of the magnitude and frequency of the applied voltage. The power losses of ZnO block increase as the frequency of applied voltage increases, because of the dielectric loss related to the frequency of the test voltage.

• Journal of Power Electronics
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• v.18 no.4
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• pp.997-1006
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• 2018

This paper proposes a transformerless photovoltaic (PV) power converter system based on the DC/AC boost inverter, which can solve the leakage current and second-order ripple power issues in single-phase grid-connected PV inverters. In the proposed topology, the leakage current can be decreased remarkably since most of the common-mode currents flow through the output capacitor, by-passing parasitic capacitors, and grounding resistors. In addition, the inherent ripple power component in the single-phase grid inverter can be suppressed without adding any extra components. Therefore, bulky electrolytic capacitors can be replaced by small film capacitors. The effectiveness of the proposed topology has been verified by simulation and experimental results for a 1-kW PV PCS.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.56 no.5
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• pp.876-883
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• 2007

The magnetic flux leakage(MFL) type nondestructive testing(NDT) method is widely used to detect corrosion, defects and mechanical deformation of the underground gas pipelines. The object pipeline is magnetically saturated by the magnetic system with permanent magnet and yokes. Hall sensors detect the leakage fields in the region of the defect. The defects are sometimes occurred in group. The accuracy of the detecting signals in this defect cluster become lowered because of the complexity of the defect cluster. In this paper, the effects of the multi -defects are analyzed. The detecting signals are computed by 3-dimensional finite element method and compared with real measurement. The results say that, rather than the size of the defects, the effects of the relative position of the multi-defects are very important on the detecting signals.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.50 no.2
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• pp.60-64
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• 2001

The degradation process of silicone rubber was investigated by leakage current monitoring in Inclined-Plane method. DAS (Data Acquisition System) with 12-bit, 8-channel A/D converter was prepared. Average current, cumulative charge, current waveform and the number of peak pulses were measured on-line. And, FFT (Fast Fourier Transform) analysis was performed with stored current waveform. Besides, maximum erosion depth was measured in order to use as the indicator of the degradation process. So, the results of leakage current components and maximum erosion depth measurements were compared to find one or more components which have trends of changing similarly to that of erosion process. The result suggests that the ratio of peak current to r.m.s. current, harmonic contents and the number of peak pulses are well corresponding with the degradation process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.322-325
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• 2002

In this study, noise figures of 0.3 $\mu\textrm{m}$-GaAs MESFETs are predicted experimentally with different temperatures. Both the noise figure and the gate leakage current are obtained with wide range of temperatures(27$^{\circ}C$∼300$^{\circ}C$). From the results, gate leakage current increases with temperatures. It is expected that gate leakage current contributes directly to the increase of shot noise current. It is therefore highly recommended to apply an accurate noise analysis to the design of the devices and modules at high temperatures. Fini,Uy the relation between the gate currents resulting in the increase of noise and the noise figures of submicron GaAs MESFETs are traced with different temperatures

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.49 no.8
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• pp.390-398
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• 2000

Leakage impulse current of the contaminated insulators by using experiment data were studied. The impulse current in phase-time relationship was analyzed on line post insulators. Also, frequency components and crest factor of the leakage current were investigated to provide a scheme for an early detection of insulator incipient failure. The study shows that the phase-time characteristic is non-stationary and random and, non-harmonic component and crest factor can be promising parameters for detecting insulator leakage currents.

• Transactions on Electrical and Electronic Materials
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• v.3 no.2
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• pp.28-31
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• 2002

The Cdl-xZnxTe film was fabricated by thermal evaporation for the flat-panel X-ray detector. The stoichimetric ratio and the crystal structure of a polycrystalline Cd$_{1-x}$ Zn$_{x}$Te were investigated by EPMA and XRD, respectively. The leakage current and X-ray sensitivity of the fabricated films were measured to analyze the X-ray response characteristic of Zn in the polycrystalline CdZnTe thin film. The leakage current and the output charge density of Cd$_{0.7}$Zn$_{0.3}$Te thin film were measured to 0.37 nA/cm$^2$ and 260 pc/cm$^2$ at an applied voltage of 2.5 V/${\mu}{\textrm}{m}$, respectively. Experimental results showed that the increase of Zn doping rates in Cd$_{1-x}$ Zn$_{x}$Te detectors reduced the leakage current and improved the signal to noise ratio significantly.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.2
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• pp.235-238
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• 2008

This paper explores 28 nm MOSFET design for LSTP(Low Standby Power) applications using TCAD(Technology Computer Aided Design) simulation. Simulated results show that the leakage current of the MOSFET is increasingly dominated by GIDL(Gate Induced Drain Leakage) instead of a subthreshold leakage as the Source/Drain extension doping increases. The GIDL current can be reduced by grading lateral abruptness of the drain at the expense of a higher Source/Drain series resistance. For 28 nm MOSFET suggested in ITRS, we have shown Source/Drain design becomes even more critical to meet both leakage current and performance requirement.