• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2004.10a
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• pp.257-262
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• 2004

As optical connectors dominate the performance of optical transmitters or receivers, they need an ultra-precise processing and are composed of optical fibers, ferrule and optical glass lenses. Therefore, this study suggests a nondestructive evaluation technique or a system using resonant ultrasound spectroscopy to evaluate flaws in a optical glass lens. It also conducted a nondestructive evaluation for flaws that are commonly found in a optical glass lens and reviewed the results.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.5
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• pp.406-412
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• 1990

In this paper, the concepts of resonant frequency control of an antennas using reactive loading are explained. Also inclueded are some useful applications of the resonant frequency controlling antennas.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.6
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• pp.376-382
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• 1988

A small-signal low-frequency disturbance of the input line affects the regulated-output voltage of the series resonant converter. To mitigate the detrimental effect, the output feedback PI-controller is employed. Small-signal linear models are represented to characterize the closed loop series resonant converter system. Design equations for the PI-controller which satisfy stability and percent ripple conditions are derived from the closed-loop linear model. Experimental results are presented which show excellent correlation with theory.

• Journal of international Conference on Electrical Machines and Systems
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• v.3 no.1
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• pp.83-87
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• 2014

This paper describes the magnetic field analysis of wireless power transfer via magnetic resonant coupling. The wireless power transfer system for supplying power to electric vehicle is developed. The parameters of coil transfer system are simulated by the finite element method (FEM). Therefore the coil structure of power transfer system can be accurately analyzed. This paper deals with 3kW wireless transfer system.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.315-316
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• 2013

This paper presents a parameter tuning method of a LLC resonant converter for a wireless charging circuit. A switched-capacitor is used to change the resonant frequency of the resonant circuit. The simulation results verify that the efficiency of the power transfer can be improved by a duty control of the switched-capacitor for various values of the coupling coefficient.

• ETRI Journal
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• v.30 no.4
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• pp.603-605
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• 2008

A novel design for equilateral-triangular microstrip antennas with switchable resonant frequency is proposed. For dual-frequency operation, the proposed design is achieved by loading a pair of slits in the triangular patch, and two PIN diodes are utilized to switch the slits on or off. By increasing the length of the slits, the lower resonant frequency can be varied in the range from 1.22 GHz to 1.72 GHz whereas the upper resonant frequency remains unchanged.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.431-434
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• 2002

In this paper, The resonant frequencies of any modes in the dielectric resonator filter is determined by numberical analysis. The theoretical analysis for the dielectric resonator filter used Ansoft HFSS. We designed the dielectric resonator filter with resonant frequency 4.5 GHz. We describe the characteristics of delivering Power to resonator in different shaped coupling loops. Tile resonant mode of T $E_{01{\delta}}$ and T $E_{01{\delta}}$ could be selected by the horizontal and the vertical coupling loop.p.

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.329-330
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• 2008

We experimentally demonstrate resonant-wavelength control of a series of an Si-based photonic crystal nanocavity. The cavities show a linear dependence on these parameters, a 1 nm increase of lattice constant leading to 4.2 nm increase of the resonant wavelength. The results have a small standard deviation of wavelength 1.1 nm between samples on a single chip.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.488-491
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• 2001

This paper investigated that resonant frequencies of microstrip patch antenna were agile when piezoelectric materials were used as the antenna substrates. The resonant frequencies of the microstrip antenna using the piezoelectric substrate. The microstrip patch antenna made of Quartz substrate was designed and fabricated by Ensemble v 7.0 simulator. The experimental problem was compensated by Ensemble v 7.0

• Journal of Power Electronics
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• v.11 no.5
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• pp.662-668
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• 2011

This paper presents an analysis of a 4th order LCLC resonant converter with a capacitive output filter using the state-space approach. The analysis of the converter shows that there are four intervals in a half period. In each interval, the state-space equations are obtained. Due to the soft switching of the converter, an exact equation for the Zero Voltage Switching (ZVS) time and the maximum dead time of the inverter switches are presented. The simulation and experimental results obtained from a 10kv, 370w prototype confirm the validity of the theoretical analysis.