• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.3
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• pp.351-358
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• 1999

This paper describes the mode identification of resonant frequencies in dielectric loaded circular cylindrical cavity. To identify the mode of resonant frequencies, the calculated resonant frequencies were compared with the simulated ones in the air-filled circular cylindrical cavity by Microstripes EM simulator. With z-oriented magnetic field excitation, we could get only TE mode resonance, while all the modes including TM mode were observed with $\phi$-oriented magnetic field excitation. We could identify the modes with the two excitation methods. We applied the identification method to a dielectric loaded circular cylindrical cavity and compared these results with experimental ones. To certify the method, we traced resonance frequencies with varying the dielectric height. We observed that the resonance of $TE_{011}$ mode was changed dramatically while the variation of the $TE_{111}$ and $TE_{211}$ modes are relatively small.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.129-130
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• 2017

본 논문에서는 자기유도방식 무선충전 시스템의 송 수신 패드 위치 변화에 따른 공진주파수 변동을 보상하기 위한 bridgeless 정류기 동작에 대해 분석한다. Bridgeless 정류기의 스위칭 시점 및 duty 변화에 따른 공진네트워크 입력임피던스의 위상 변화를 수식적으로 분석하고, 시뮬레이션을 통하여 분석 결과를 검증한다.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.2
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• pp.218-226
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• 1999

This paper describes resonant mode selection with which the relative permittivity can be measured exactly. To measure the relative permittivity, a circular cylindrical cavity filled with dielectric material is used. When the circular cylindrical cavity is filled with the dielectric material, the air gap occurs on account of machining error. Accurate relative permittivity can be obtained by using less sensitive mode in resonant frequency variation by the air gap. As a result, Average 0.009% resonant frequency variation in the vertical and the radial direction appears at $TE_{011}$ mode. It is interesting that the frequency variation by the air gap at $TE_{011}$ mode turns out to be the least sensitive.

• Proceedings of the Acoustical Society of Korea Conference
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• 1993.06a
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• pp.181-185
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• 1993

물 속에 만들어진 공기방울들은 각자 자신의 반지름에 반비례하는 공진주파수로 음파를 방출하며, 많은 공기방울들이 모인 공기방울 집단은 집단의 전체 크기에 반비례하는 집단 공진주파수를 가진다는 현상이 그동안 연구되어 왔다. 그러나, 수십, 수백 개의 유한한 개수를 가진 공기방울들의 음파방출 주파수 특성 연구는 부족한 실정이다. 본 연구에서는 수중에 일차원 배열의 공기방울들을 발생시켜 공기방울들에서 나오는 음파방출 주파수를 측정하였다. 수중에 형성된 공기방울들은 그들 간에 거리 간격이 존재하므로 본 연구에서는 공기방울들 간의 상호작용이 변화한다고 간주한 유효 결합 조화진동자 모형을 새로이 만들어 해석하였으며, 실험값과 좋은 이치를 보여주었다.

• Proceedings of the Optical Society of Korea Conference
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• 2001.02a
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• pp.254-255
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• 2001

매질의 공진주파수 근처에서는 주파수가 커짐에 따라 매질의 굴절률이 감소하는 비정상 분산 특성을 나타낸다. 본 실험에서는 세슘원자의 비정상 분산 특성을 실험적으로 관측할 수 있는 방법을 연구하였다. 가열된 세슘원자셀(16$0^{\circ}C$)에 CS D$_2$ 전이선에 공진되는 레이저빔을 입사하여 레이저의 주파수에 따른 레이저빔의 굴절각도를 측정하였다(그림1) 레이저빔의 굴절각의 변화를 용이하게 측정하기 위해 원자셀 벽에 굴절률이 1.5 인 프리즘을 장착하고 원자빔을 전반사의 임계각보다 조금 작은 각도로 입사하여 투과광의 굴절각을 측정하였다. (중략)

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.2
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• pp.25-30
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• 2010

In this paper, a novel notch resonator is proposed based on Rectanglar Split Ring Resonator (R-RSS) element. We represented the electrical characteristics for R-SRR elements coupled with microstrip line, and measured result is compared with electromagnetic simulation (HFSS) result. We also solved equivalent circuit for R-SRR element, and also discussed influences of change structural parameters of R-SRR. the size of R-SRR is the most important parameters for frequency tuning. Also we can make tunable resonator form the basic structure. This novel resonator can apply to design of tunable bandpass filter and voltage control oscillator.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.2
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• pp.133-138
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• 1987

In this paper the tuning characteristics of resonant frequencies are experimentally studied through the variation of the length of the inner conducting rod in a re-enterant eavity resonator. The re-enterant eavity resonator consists of a coaxial cable and a cylindrical wave guide. The length of the inner conducting rod can be varied to the longitudinal direction. The resonant frequencies of TMonq modes are measured according to the arbitrary length. In order to verify the propriety of experimental results, experimental results are compared with other theoretical results. The results in this paper can be applied to wave meter and resonant circuit of amplifier. They will be use to vary resonant frequencies of a dielectric resonator in MIC and filter.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.21 no.2
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• pp.73-78
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• 2021

To minimize the resonance frequency error when design Inset-Fed Microstrip Patch Antenna using current formulas. Especially It is found that a constant relation between Antenna patch width and frequency error. Using this relation, calculation frequency and simulation frequency are compared. Finally the comparison induced a formula of revised antenna patch width for accurate frequency in 2-10 GHz. And this formula reduced 2.54% of average frequency error. Last, the Antenna which has same variation with the simulation was producted and measured. It proved the formula's validity.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.19 no.10
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• pp.1982-1990
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• 1994

We implemented a PLDRO(Phase Locked Dielectric Resonator Oscillator) using the concept of the feedback property of PLL(Phase Locked Loop) for Ku-band(10.95-11.70 GHz). The conventional approaches to a PLDRO design use varactor diode tuning method.. But in theis paper, the PLDRO has the advantage of the frequency sensitivity to changes in the supple voltage of the oscillating device without the frequency-variable part by varactor diode voltage-control. and uses a SPD(Sampling Phase Detector) for phase-comparision. The PLDRO is composed of the DRO phase-locked to the reference signal of UHF band by using a SPD for high frequency stability and can be available for European FSS(Fixed Satellite Service) at 10.00GHz. The PLDRO generates the output power of 8.67 dBm at 10.00 GHz and has a phase noise of -81 dBc/Hz at 10 kHz offset from carrier. The hamonic and spurious characteristics have -42.33 dBc and -65dBc respectively. This PLDRO has much better frequency stability, lower phase noise, and more economical effect for a satellite system than conventional DRO.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.11
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• pp.1121-1127
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• 2014

In this paper, a planar frequency reconfigurable antenna is proposed with variable capacitors. The proposed one is designed with a planar monopole, and varies resonant frequencies by variable capacitive loading of a varactor diode. The equivalent circuit and electromagnetic(EM) simulation are utilized for the analysis at the variable characteristic design of the antenna, and the same radiation performance. The implemented frequency variable monopole antenna has been verified by comparing prototypes with designed capacitors and ones with biased varactor diodes. The proposed antenna has presented the resonant frequency variations from 2.25 GHz to 2.42 GHz.