• Title, Summary, Keyword: Cavity resonator

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A Study of the Estimation Method for the Dielectric Properties of Dielectrics in Millimeter Wave Range - Part II (유전체의 밀리미터파대 유전특성 평가방법에 관한 연구 II)

  • 이홍열;전동석;김동영;이상석
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.12
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    • pp.1087-1090
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    • 2003
  • The circular cavity resonator which can measure the dielectric properties of dielectrics in the V -band(50㎓∼75㎓) frequency range was designed and fabricated. Exciting and detecting of the resonator is performed by WR15 rectangular waveguides using Bethe's small hole coupling. GaAs and PTFE plate samples were used for the verification of the performance of the fabricated circular cavity resonator. In the measurement of GaAs and PTFE using that resonator, the permittivity were measured as I2.87 and 2.14, respectively.

A Study of the Estimation Method for the Dielectric Properties of Dielectrics in Millimeter Wave Range - Part II (유전체의 밀리미터파대 유전특성 평가방법에 관한 연구 II)

  • Lee, Hong-Yeol;Jun, Dong-Suk;Kim, Dong-Youn;Ko, Kyoung-Suk;Lee, Sang-Seok
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.135-138
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    • 2003
  • The circular cavity resonator which can measure the dielectric properties of dielectrics in the V-band($50GHz{\sim}75GHz$) frequency range was designed and fabricated. Exciting and detecting of the resonator is peformed by WR15 rectangular waveguides using Bethe's small hole coupling. The GaAs plate sample was used for the verification of the performance of the fabricated circular cavity resonator. In the measurement of GaAs single crystal using that resonator, the resonant frequency of the dominant $TE_{011}$ mode, the permittivity and $Q{\times}f_0$ were measured as 53.29GHz, 12.87 and 138,000, respectively.

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Noise Reduction Characteristics of a Double Air-gap Resonator (이중 에어갭 공명기의 소음 저감 특성)

  • 강상욱;이장무
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.202-207
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    • 2003
  • In the paper, the noise reduction characteristics of a double-gap resonator, which is installed inside an enclosed cavity and is composed of two air-gaps and two partition sheets, are introduced by theoretical analyses and experimets. Analysis for a simple, theoretical model reveals that the double-gap resonator is more effective than the single-gap resonator that consists of an air-gap and a partition sheet, in that the former requires a smaller space than the latter. Furthermore, this theoretical conclusion is verified by comparison experiments using an actually manufactured enclosed cavity, of which the boundary surfaces are made of thick, stiff panels that can be assumed as rigid walls.

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Design of a Planar Cavity Resonator for 12.5 GHz Low Phase Noise SiGe HBT Oscillator

  • Lee Jae-Woo;Kim Yong-Hoon
    • Journal of electromagnetic engineering and science
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    • v.5 no.4
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    • pp.153-160
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    • 2005
  • In this paper, the novel microwave oscillator incorporating a planar cavity resonator(PCR) is presented to reduce the phase noise of the oscillator in a planar environment. Compared to the conventional planar( $\lambda$/4 open stub resonator), the phase noise is improved about 16 dBc/Hz @100 kHz. The design of the oscillator is based on a reflection type configuration using the low 1/f SiGe HBT transistor(LPT16ED). The output power is measured 2.76 dBm at 12.5 GHz. In this paper, the oscillator used to the PCR can be expected to provide a solution for low phase noise oscillator in microwave circuits.

Forced Acoustic Response Analysis of an Acoustic Cavity with a Double Air-gap Resonator for Reducing Passenger Compartment Noises (차실 소음 저감을 위한 복층 에어갭 공명기가 설치된 음향 공동의 강제 음향 응답 해석)

  • Kang, Sang-Wook
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.6
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    • pp.163-169
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    • 2005
  • A theoretical formulation on the forced acoustic response of an enclosed cavity having a double air-gap resonator on one of boundary panels of the cavity is developed in the paper. The double gap resonator consists of two air-gaps and two partition sheets as in the author's previous papers. This paper reveals that the double gap resonator reduces the level of a target noise peak by splitting the peak as two small peaks, and that it is more effective when it is designed so that the upper gap thickness is larger than the lower gap thickness under the constraint that the entire gap thickness is fixed as a constant value. Finally, verification experiments show that the theoretical formulation and analysis results are valid by comparing theoretical results with experimental ones.

Compact Cascaded Quadruplet Bandpass Filter Using Modified Coaxial Cavity Resonator with Q-Factor Improvement (품질계수가 향상된 변형된 동축 공동 공진기를 이용한 다단 Quadruplet 대역통과 여파기)

  • Jang, Geon-Ho;Wang, Xu-Guang;Lee, Bo-Ram;Park, Nam-Shin
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.11
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    • pp.966-977
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    • 2015
  • This paper presents a novel modified coaxial cavity resonator and its application to bandpass filters with compact size and improved quality factor(Q-factor). The proposed resonator is made up of ${\Gamma}-shape$ or curved four inner conductive posts within a single cavity, which provides quadruplet to realize bandpass filter. No metallic walls inside the cavity are required, and thus the utilization efficiency of the cavity space is improved. As a result, the unloaded Q can be approximately 15 % higher in comparison to the conventional coaxial resonator, or more than 35 % volume saving can be achieved while maintaining the similar Q-factor value with the conventional designs. In addition, due to the multiple cross-coupling occurring within the cavity, including the source-to-load coupling, four flexible transmission zeros can be created to realize different filtering functions. Simulations as well as experimental results of four- and eight-pole filters are presented to validate this attractive design concept. Good agreement between measured and computed results is obtained.

Control of Sound Pressure Inside a Flow Excited Resonator (유동가진 공명기 내부의 음압 제어)

  • Hwang, Cheol-Ho;Park, Jong-Beom
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.196-199
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    • 2005
  • Flow traveling over a cavity opening forms a vortex due to unstable shear layer and induces an aerodynamic pressure excitation from the diffusion of the vortex convecting out of the trailing edge of the opening. The interaction between the excitation force and the cavity response sustains resonance in the resonator(cavity) and locked-in vortex shedding at the leading edge of the opening. The aerodynamic excitation force can be described from the diffusion of the vortex over the trailing edge and the level of its diffusivity is related to the strength of vorticity seeded at the loading edge. In this study, the control scheme of the internal pressure oscillation was proposed from regulating the vorticity at the leading edge by use of an oscillating spoiler. It was found that the relative motion between the spoiler and the air mass at the cavity opening influenced vorticity strength and the control was achieved by direct feedback of the cavity pressure fluctuation to the actuator.

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Microwave Dielectric Absorption Spectroscopy Aiming at Novel Dosimetry Using DNAs

  • Izumi, Yoshinobu;Hirayama, Makoto;Matuo, Youichirou;Sunagawa, Takeyoshi
    • Journal of Radiation Protection and Research
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    • v.42 no.1
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    • pp.21-25
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    • 2017
  • Background: We are developing L-band and S-band microwave dielectric absorption systems aiming novel dosimetry using DNAs, such as plasmid DNA and genomic DNA, and microwave technology. Materials and Methods: Each system is composed of a cavity resonator, analog signal generator, circulator, power meter, and oscilloscope. Since the cavity resonator is sensitive to temperature change, we have made great efforts to prevent the fluctuation of temperature. We have developed software for controlling and measurement. Results and Discussion: By using this system, we can measure the resonance frequency, f, and ${\Delta}Q$ (Q is a dimensionless parameter that describes how under-damped an oscillator or resonator is, and characterizes a resonator's bandwidth relative to its center frequency) within about 3 minutes with high accuracy. Conclusion: This system will be expected to be applicable to DNAs evaluations and to novel dosimetric system.

A Study of the Estimation Method for the Dielectric Properties of Dielectrics in Millimeter Wave Range using Bethe's Small Hole Coupling (Bethe's Small Hole Coupling을 이용한 유전체의 밀리미터파대 유전특성 평가방법에 관한 연구)

  • Lee, Hong-Yeol;Jun, Dong-Suk;Hahn, Jin-Woo;Lee, Sang-Seok
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.1136-1139
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    • 2002
  • The circular cavity resonator which can measure the dielectric properties of dielectrics in the Ka-band(26.5GHz~40GHz) frequency range was designed and fabricated. A structure of the resonator is divided into two equal parts of the length and the dielectric plate sample is placed between two halves. Exciting and detecting of the resonator is performed by WR28 rectangular waveguides using Bethe's small hole coupling. The GaAs plate sample, whose permittivity is known to be 13 in millimeter wave range, was used for the verification of the performance of the fabricated circular cavity resonator. In the measurement of GaAs single crystal using that resonator, the resonant frequency of the dominant $TE_{011}$ mode, the permittivity and $Q{\times}f_0$ were measured as 26.69GHz, 12.9 and 124,000GHz, respectively.

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A Study of the Estimation Method for the Dielectric Properties of Dielectrics in Millimeter Wave Range using Bethe's Small Hole Coupling (Bethe's Small Hole Coupling을 이용한 유전체의 밀리미터파대 유전특성 평가방법에 관한연구)

  • 이홍열;전동석;한진우;이상석
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.15 no.12
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    • pp.1085-1089
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    • 2002
  • The circular cavity resonator which can measure the dielectric properties of dielectrics in the Ka-band(26.5GHz∼400Hz) frequency range was designed and fabricated. A structure of the resonator is divided into two equal parts of the length and the dielectric plate sample is placed between two halves. Exciting and detecting of the resonator is Performed by WR28 rectangular waveguides using Bethe's small hole coupling. The GaAs plate sample, whose performance is known to be 13 in millimeter wave range, was used for the verification of the performance of the fabricated circular cavity resonator In the measurement of GaAs single crystal using that resonator, the resonant frequency of the dominant TE$\sub$011/ mode, the permittivity and Q${\times}$f$\sub$0/ were measured as 26.69GHz, 12.9 and 124,000GHz, respectively.