• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.2
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• pp.119-125
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• 2004

This paper is described the indirect induction heated boiler system and induction heated hot air producer using the voltage-fed series resonant high-frequency inverter which can operate in the frequency range from 20〔KHz〕 to 50〔KHz〕. A specially designed Induction heater, which is composed of laminated stainless assembly with many tiny holes and interconnected spot welding points between stainless plates, is inserted into the ceramic type vessel with external working coil. This working coil is connected to the resonant inverter. In the induction heater, it's primary heating section creates low-pressure saturated steam and secondary heating section generates heat distribution evaporating fluid from the turbulence fluid which is flowing through the vessel. The operating performances of this unique appliance in next generation and its effectiveness are evaluated and discussed from the practical point of view.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.166-167
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• 2007

본 논문은 고주파 IH(Induction Heating) 조리기기의 전원으로 사용되는 인버터를 PI 제어기를 사용하여 듀티비를 가변시켜 출력을 최적 제어하는 회로를 제시하였다. 분석에 사용된 기본 인버터 회로는 Single-Ended Push-Pull (SEPP) 영전류 스위칭 공진인버터이며 실제 IH 조리기기의 동작을 구현하기 위해 입력단의 전원으로 220V 60Hz 정현파와 브리지 정류기, 평활 콘덴서를 사용하였다. 회로의 해석과 시뮬레이션을 위해 범용 시뮬레이션 툴인 Pspice를 이용하여 분석하였다. 향후, 제안된 제어방법은 유사한 IH 기기, DC-DC 컨버터, 인덕션 모터등의 시스템에 활용되리라 기대된다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.2
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• pp.9-17
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• 2002

A high-efficiency electronic ballast for HID lamps is presented. The ballast consists of a PFC and a resonant inverter. To reduce losses of the ballast, DC link voltage should be determined by taking into account the peak voltage of lamp and the maximum flux density should be kept 0.2[T] on all of inductors. AR inductor at bridge diode is employed in order to remove currant harmonics from PFC. An inductor is connected in series with an electrolytic capacitor at DC link to reject high-frequency current. The acoustic resonance is eliminated using the stead spectrum technique. The electronic ballast for 250[W] metal-halide discharge lamp is implemented and 96[%] efficiency, no acoustic resonance and low conducted EMI level are accomplished.

• Journal of the Institute of Electronics and Information Engineers
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• v.50 no.12
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• pp.22-29
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• 2013

The combined structure of both an annular dielectric resonator and a quarter-wave monopole is proposed to generate an omnidirectional radiation pattern over the wideband frequency range. The monopole works at the lower frequency band and excites the cylindrical dielectric resonator along its center point by electrical coupling mechanism. The rectangular shape of the DR is cut to generate the wideband operation of 4.7-18.2 GHz. The geometrical parameter of cylindrical dielectric resonator is 5.8 mm, 11.6 mm and 6.0 mm in inner diameter, outer diameter and height, respectively.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.5
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• pp.223-228
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• 2018

In this paper the water sensor using a coaxial cavity resonator is designed and manufactured. The water sensor which can sense water drop linearly has been constructed with voltage controlled oscillator(VCO), coaxial cavity resonator, RF switch, RF detector, A/D converter, DAC and micro controller. The operating frequency range of the designed water sensor is from 2.5GHz to 3.2GHz and the input voltage and current source are 24[V/DC] and 1[A]. The designed sensor circuit includes VCO, RF switch, RF detector which varies the frequency characteristics of the devices in the high frequency of 3GHz. And so we should correct the error of the frequency characteristics of those devices in the sensor circuit. To do this, we make the reference path which switches the signals to the RF detector directly without sending it to the resonator. According to the result of simulation and measurement, we can see that there is 0-50MHz difference between simulated resonator frequency and manufactured resonator frequency.

• Proceedings of the KIPE Conference
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• 2006.06a
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• pp.56-58
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• 2006

본 논문은 PVD(Physical Vapor Deposition)의 마그네트론 스퍼터(Magnetron sputter) 박막코팅(Thin film coating) 공정에서 플라즈마(Plasma)를 발생시키고 제어하는 DC 전원공급 장치에 관한 것이다. 이 논문에서는 임피던스의 변화가 심하고 아크(Arc)가 빈번히 발생하는 플라즈마 부하의 특성에 대해, 과도상태(Transient state)의 출력제어 성능을 향상시키고 아크 발생 시 부하로 전가되는 아크에너지를 저감시키기 위한 직류 전원 공급 장치에 대해 소개한다. 전원장치는 수하특성을 가지며 플라즈마 부하에 적합한 출력 제어성을 확보하고 아크 에너지를 최소화하기 위해 고주파 L-C 직렬공진회로 기법을 적용한다. 개발된 DC 20kW급 전원 장치는 인버터와 고주파 절연변압기, 정류기로 구성된다. 인버터는 $100{\sim}200kHz$의 제어주파수로 PFM 및 PWM 제어를 하며, 단위용량 5kW급 컨버터 4개를 직, 병렬 연결하여 출력리플을 최소화 하였다. 개발된 장치의 우수한 제어성능은 실제 플라즈마 공정에서 시험 평가한 결과를 통해 검증할 수 있었다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.3
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• pp.528-535
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• 2011

In this paper, a compact doppler sensor with oscillator type active antenna operating at 2.4GHz frequency band is proposed to measure the distance to a moving object. The oscillation frequency is shifted depending on approaching of the object, and a detection circuit discriminates the frequency deviation. The active antenna has been designed and simulated. The prototype fabricated has a small circular disk type of diameter 30mm and height 4.2mm. As for antenna performance, broadside radiation pattern with beamwidth of $120^{\circ}$ and oscillation frequency of 2.35GHz has been measured. Test results as a range sensor shows that signal voltage of about 240mV has been obtained for conducting plate moving 1 meter away from the sensor. And, signal voltage has been linearly increased to the ground from 5m height by free-falling the sensor.

• Korean Journal of Materials Research
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• v.11 no.11
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• pp.923-928
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• 2001

An electrolytic silver plating process has been successfully developed for terminated electrode parts of dielectric ceramic resonator. High adhesion strength and high Qu is obtained and blister occurance is minimized under plating condition with $HNO_3$750 $m\ell/\ell$ and HF $ 250m\ell/\ell$ solution at $25^{\circ}C$ for 20 minutes. Adhesion strength has the highest value, 3.2 kg/mm$^2$ at etching temperature of $25^{\circ}C$. Adhesion strength, Qu and blister occurance are monotonically increased with the thickness of electrodeposition layer. In case of electrodeposition of Ag, Qu value of 380 has obtained higher than in case of electrolytic Cu plating with Qu value of 325. Therefore, terminated electrode parts of dielectric ceramic resonator reducing dielectric loss can be obtained using prensent process.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.2
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• pp.200-207
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• 2009

This paper presents a compact, low insertion loss, sharp rejection and wide band microstrip band pass filter that is composed rectangular loop resonator and Step-Impedance-Open-Stub(SIOS). The SIOS can be reduce length about 30 % more than general 0.25 $\lambda$ open stub. And the stub can the advantage of tuning impedance magnitude. In order to demonstrate agrement of this paper prove, the optimized wide band pass filters are realized and experimented. A transmission line model used to calculate the frequency response of the new filters shows good agreement with measurements. The filter has 3 dB fractional bandwidth of 51.75 %(3.206 GHz), an insertion loss of better than 0.44 dB from 4.587 GHz to 7.793 GHz, and two rejection of greater than 30 dB within 221 MHz($4.326{\sim}4.587\;GHz$) at low frequency band, 181 MHz($7.739{\sim}7.954\;GHz$) at high frequency band. Maximum rejection characteristics of the filter are -61.8 dB at low frequency and -76.3 dB at high frequency.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.147-148
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• 2016

본 논문에서는 원격 플라즈마 발생장치 (Remote Plasma Generator, RPG)에 적용하기 위한 공진형 토폴로지에 대해 비교한다. 원격 플라즈마 발생장치는 AC-DC 정류기, DC-AC 인버터, 공진탱크, 플라즈마 발생용 리액터, 점화장치로 구성되며, 이는 기존의 SMPS와 유사한 구성이다. 하지만 플라즈마 부하는 기존의 전력전자 어플리케이션들과는 달리 점화조건과 플라즈마 유지 조건을 충족시켜야 한다는 특징이 있다. 따라서 본 논문에서는 각 공진형 토폴로지들의 특성 비교 분석을 통해 원격 플라즈마 발생장치에 대한 적용 가능성에 대한 분석을 수행하였으며, 시뮬레이션을 통해 검증하였다.