• Proceedings of the KIPE Conference
• /
• 2011.07a
• /
• pp.479-480
• /
• 2011

본 논문은 150W HID 램프용 안정기의 공진 점등에 관한 것으로, 기존의 외부 펄스에 의한 점등 시 램프와 안정기의 거리에 따른 점등전압의 감쇠를 감소시키고자 내부 LC를 이용한 공진 점화부로 하여 기능을 향상하였으나, 벅 컨버터의 인덕터와 커패시터로 공진 기동하여 고전압 점등 파형을 만드는 과정 중 스위치 전류가 커지는 문제가 발생하여, 점등을 위한 공진용 커패시터용량을 줄여 공진 Q점을 나눈 별도의 L(T1)과 C(C2, C3)를 공진 탱크로 이용하여 점등하도록 하였으며, 공진 공진주파수로의 주파수 SWEEP 및 재 점등을 하기 위하여 마이크로프로세서를 이용하였다.

• Proceedings of the KIPE Conference
• /
• 2006.06a
• /
• pp.375-377
• /
• 2006

본 논문에서는 LLC 공진형 컨버터의 최적 설계를 위해, ZVS 영역에서 동작하는 LLC 공진형 컨버터의 최악의 상태에 대한 정상 상태 해석을 하였다. LLC 공진형 컨버터의 최악의 상태는 최소 입력 전압, 최대 부하 전류일 때 얻을 수 있는 최대 전압 이득을 의미한다. 설계 변수는 스위칭 주파수 범위와 공진 인덕터 비율로서, 각 설계 변수의 변화에 따른 공진 탱크 설계 값, 최악의 상태 출력 전압 그리고 최대 공진 캐패시터 전압을 보여주는 '최악의 조건 설계 표'를 나타내었으며, 설계된 특정 공진 탱크 값에 대한 시뮬레이션 결과와 실험 결과를 보였다.

• Proceedings of the KIPE Conference
• /
• 2010.07a
• /
• pp.214-215
• /
• 2010

본 논문은 공진 인버터를 적용한 HID램프를 구동하기 위한 전자식 안정기를 설계하고 구현하였다. 제안된 전자식 안정기는 스위치 턴온 오프시의 손실을 줄이기 위해서 소프트 스위칭 기법인 ZVS(Zero-Voltage Switching)을 도입하였다. 점등은 LC필터의 공진주파수범위에서 풀브리지 인버터 제어에 의한 공진으로 이루어 진다. 점등후에 컨버터는 저주파수 구형파로 동작한다. 공진 기동시의 LC필터의 공진주파수는 ($f_o$=160kHz)이고, 고조파를 감소시키고 음향공진현상을 피하기 위한 벅컨버터 스위칭 주파수(고주파수 : 50~60kHz 와 저주파수 : 170Hz)를 선택하였다. 실험을 통해 공진 인버터를 적용한 HID램프용 전자식 안정기가 안정적으로 동작함을 확인하였다.

• Proceedings of the KIPE Conference
• /
• 2014.07a
• /
• pp.299-300
• /
• 2014

본 논문에서는 넓은 입력전압 및 부하 변동에 적합한 대전력용 $L^3C$ 공진형 컨버터를 제안한다. 제안하는 컨버터는 직렬공진탱크와 병렬공진탱크를 조합하여 승압과 강압이 가능하며 다른 공진형 컨버터에 비해 적은 주파수 변동에도 넓은 입출력 범위를 만족 시킬 수 있다. 제안하는 컨버터는 삼차권선을 이용하여 공진 탱크를 구성하기 때문에 공진 커패시터에 흐르는 전류를 최소화 할 수 있으며 공진에 참여하는 인덕터는 변압기의 누설 인덕턴스를 사용하여 소자를 최소화 할 수 있다. 제안하는 컨버터의 스위칭 특성의 경우 모든 스위치가 ZVS 턴온을 달성하고 다이오드는 ZCS 턴온/턴오프가 가능하다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.23 no.3
• /
• pp.343-354
• /
• 2012

In this paper, various spiral zeroth-order resonators are proposed for wireless power transmission. Since a zerothorder resonance(ZOR) mode of meta-material transmission lines has the characteristic of an infinite wavelength, its frequency is independent of physical length. Also, to obtain high transmission efficiencies high-Q resonators and strong coupling coefficient between coupled resonators are required. Therefore, the resonators consist of spiral inductor and lumped capacitor to use the ZOR mode and they are optimized via parametric study and circuit analysis for a high-Q resonator design. The optimized resonators are simulated and compared with a conventional spiral resonator and one of them was fabricated and measured. The fabricated one has a dimension of $20cm{\times}20cm{\times}8cm$($0.009{\lambda}_0{\times}0.009_{\lambda}_0{\times}0.004{\lambda}_0$) and the transmission efficiency of 80 % is measured at 13.56 MHz at transmitted distance of 40 cm.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
• /
• v.18 no.7
• /
• pp.796-808
• /
• 2007

In this paper, two novel compact microstrip bandstop filters using complimentary split ring resonators(CSRRs) and spiral resonators is proposed. The first one is the bandstop filter using an array of CSRRs etched on the center line of a microstrip. The bandstop is due to the presence of negative effective permittivity and positive permeability near resonant frequency which prevent the wave propagation. The second on is the bandstop filter using an array of spiral resonators etched on the center line of a microstrip. The bandstop is due to the self-resonance of spiral circuit. We have achieved controllable resonance frequency and bandwidth, super compact dimension, low insertion losses in the passband and high level of rejection in the stopband with sharp cutoff. The electrical sizes of two proposed filter are very small. Additionally, they can be easily fabricated and compatible with MMIC or PCB technology.

• Journal of the Korean Vacuum Society
• /
• v.21 no.1
• /
• pp.36-40
• /
• 2012

We have developed the detection method of the resonance frequency of micro/nano mechanical resonator using optical method. The optical interferometery method enabled us to detect the displacement change of resonators within several nm scale. The micro mechanical resonator was produced by attaching a micro mechanical cantilever to a piezo ceramic. The mass of cantilever was increased by evaporating Au using electron beam evaporator and the mass variation was estimated by detecting the resonance frequency changes.

• Journal of Advanced Navigation Technology
• /
• v.26 no.6
• /
• pp.516-521
• /
• 2022

In this paper, a compact 4-bit chipless RFID(radio frequency identification) tag using a modified ELC(electric field-coupled inductive-capacitive) resonator and multiple slot resonators is proposed. The modified ELC resonator uses an interdigital-capacitor structure in the conventional ELC resonator to lower the resonance peak frequency of the RCS. The multiple slot resonators are designed by etching three slots with different lengths into an inverted U-shaped conductor. The resonant peak frequency of the RCS for the modified ELC resonator is 3.216 GHz, whereas those of the multiple slot resonators are set at 4.122 GHz, 4.64 GHz, and 5.304 GHz, respectively. The proposed compact four-bit tag is fabricated on an RF-301 substrate with dimensions of 50 mm×20 mm and a thickness of 0.8 mm. Experiment results show that the resonant peak frequencies of the fabricated four-bit chipless RFID tag are 3.285 GHz, 4.09 GHz, 4.63 GHz, and 5.31 GHz, respectively, which is similar to the simulation results with errors in the range between 0.78% and 2.16%.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.19 no.2
• /
• pp.355-360
• /
• 2024

In this paper, in implementing a 4-coil resonant wireless power transmission system, we studied the discharge phenomenon that occurs at the end of the transmitting resonance coil. Resonant wireless power transmission consists of a power supply coil, a transmitting resonance coil, a power receiving resonance coil, and a load coil. The transmitting resonance coil serves to amplify the magnetic field generated from the power supply coil and transmits it to the front receiving resonance coil. When a high current flows through the power supply coil in order to transmit large power, a high voltage is induced at the end of the transmitting resonance coil. It causes line-to-line discharge. Line-to-line discharge phenomenon damages the transmitter case and renders the transmitter unusable. Therefore, in order to eliminate this line-to-line discharge phenomenon, the voltage induced in the transmitting resonance coil that causes line-to-line discharge was analyzed and a solution was proposed.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.13 no.4
• /
• pp.201-208
• /
• 2013

This paper is a study of an empirical design of an open-ended coaxial cavity resonator. It can be done by using the radius of the inner conductor, the inner radius and the length of the resonator. However, the basic coaxial transmission -line theory can be seen that the characteristics of the resonant frequency and the Q value are varied by the change of length, regardless of the value of radius of the inner conductor and inner radius of the resonator. We find out the impact of radius of the inner conductor, inner radius of the resonator and the length of the resonator parameter and propose the optimized empirical resonator design method by reducing the error between the theoretical value and the design value. Based on the simulation, several resonators are fabricated by the size of 14 mm for the radius of inner conductor, 2 mm, 5 mm, 10 mm respectively for the inner radius of resonator, and 8.5 mm for the length of the resonator. The resonant frequencies of the produced resonators were measured at 6.1, 5.7, 6.5 GHz respectively. According to the result of simulation and measurement, we know that we can design the relatively exact open-ended coaxial cavity resonator by applying the basic coaxial transmission-line theory directly when the length of the resonator is less than 10 mm, and adding the correction factor of 0.5 GHz to the calculated resonant frequency in case of more than 10 mm of the length of the resonator.