• Title/Summary/Keyword: Microwave resonator

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A Study on the Microwave Electric-Field Focusing Waveguide Systems for Driving Plasma Visible Light (플라즈마 가시광 구동을 위한 초고주파 전계 집속형 도파관 시스템에 관한 연구)

  • Jeon, Hoo-Dong;Park, Eui-Joon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.3
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    • pp.303-312
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    • 2009
  • In this study, a waveguide system for focusing the electric field is presented to emit the microwave-driven plasma visible light. This system consists of a magnetron for the microwave power supply, the waveguide section for power propagation, and the mesh-type cavity reactor. The quartz bulb containing a dose of sulfur powder and buffer gas Ar is located in the reactor, and forced by the strongly concentrated electric field for generating and exciting the sulfur plasma. That is, the conductor tips are loaded on each inner wall of the waveguide and the reactor, and then the plasma bulb is positioned between the tips, hence focusing the strong electric field on the bulb. Furthermore the waveguide section is designed for minimizing the degradations of matching characteristics according to the variations of the electrical conductivities of plasma at the transitory phase for plasma generation, hence providing the stable operation. Finally, the 2.45 GHz aluminum waveguide system is constructed, and then experiments for emitting the visible light are performed by using 400 W-class magnetron, showing the validity of designed system.

Design of a Ultra Miniaturized Voltage Tuned Oscillator Using LTCC Artificial Dielectric Reson (LTCC 의사 유전체 공진기를 이용한 초소형 전압제어발진기 설계)

  • Heo, Yun-Seong;Oh, Hyun-Seok;Jeong, Hae-Chang;Yeom, Kyung-Whan
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.5
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    • pp.613-623
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    • 2012
  • In this paper, we present an ultra miniaturized voltage tuned oscillator, with HMIC-type amplifier and phase shifter, using LTCC artificial dielectric resonator. ADR which consists of periodic conductor patterns and stacked layers has a smaller size than a dielectric resonator. The design specification of ADR is obtained from the design goal of oscillator. The structure of the ADR with a stacked circular disk type is chosen. The resonance characteristic, physical dimension and stack number are analyzed. For miniaturization of ADRO, the ADR is internally implemented at the upper part of the LTCC substrate and the other circuits, which are amplifier and phase shifter are integrated at the bottom side respectively. The fabricated ADRO has ultra small size of 13×13×3mm313×13×3mm3 and is a SMT type. The designed ADRO satisfies the open-loop oscillation condition at the design frequency. As a results, the oscillation frequency range is 2.025~2.108 GHz at a tuning voltage of 0~5 V. The phase noise is 109±4 dBc/Hz at 100 kHz offset frequency and the power is 6.8±0.2 dBm. The power frequency tuning normalized figure of merit is -30.88 dB.

Cobalt (Co) Electrode FBAR Devices Fabricated on Seven-Layered Bragg Reflectors and Their Resonance Characteristics

  • Mai Linh;Yim, Mun-Hyuk;Yoon, Gi-Wan;Kim, Dong-Hyun
    • Journal of information and communication convergence engineering
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    • v.1 no.3
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    • pp.129-132
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    • 2003
  • In this paper, cobalt (Co)-electrode FBAR devices fabricated on seven-layered Bragg Reflectors are presented along with their resonance characteristics. ZnO films are used as the resonating material in FBAR devices where the Co electrode is 3000\AA thick. All processes are preformed in an RF magnetron sputtering system. As a result of characterization, the resonance characteristics are observed to depend strongly on the quality of ZnO film and Bragg Reflectors. In addition, the FBAR devices with W/SiO2 reflectors show good resonance characteristics in term of return loss and quality-factor (Q-factor).

Design of dual-mode bandpass DR filter in a loaded cavity (유전체 공진기가 삽입된 공동공진기를 이용한 이중모드 대역통과 필터의 설계)

  • Park, Do-Young;Yoon, Soon-Il;Park, Mie-Hwa;Na, Seong-Uk;Lee, Kie-Jin
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2004.07b
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    • pp.578-581
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    • 2004
  • 유전체가 삽입된 공동 공진기는 유전체에 대부분의 전자계가 집속되어 있기 때문에, 도체 손실이 매우 적고 높은 Q값과 온도 안정성이 뛰어나다. 동일한 주파수에서 동작하는 다른 필터에 비해 상대적으로 작기 때문에 소형화에도 적합하다. 본 논문에서는 유전체가 삽입된 공동 공진기의 전자기 분포와 특성을 수치해석과 HFSS(High Frequency Structure Simulator)를 이용하여 분석하였고 이 결과를 토대로 HFSS를 이용한 순차적 방법을 도입하여 4-pole 이중모드 대역통과 필터를 설계, 제작하였다.

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A study of 10.5 GHz band Doppler radar for non-contact type hydrometer (비접촉식 유속계를 위한 10.5 GHz 대역 도플러 레이더에 대한 연구)

  • Kim, Jin-Su;Hwang, Hee-Yong
    • Journal of Industrial Technology
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    • v.29 no.B
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    • pp.139-144
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    • 2009
  • A Doppler radar is a radar using the doppler effect of the returned echoes from targets to measure their radial velocity. To be more specific the microwave signal sent by the radar antenna's directional beam is reflected toward the radar and compared in frequency, up or down from the original signal, allowing for the direct and highly accurate measurement of target velocity component in the direction of the beam. In this paper, we designed the doppler radar composed of 10.5 GHz band DROs(Dielectric Resonator Oscillator), 90C branch line coupler, single balanced mixer and 4×4 array antenna of high gain, high directivity, for non-contact type hydrometer. Fabricated Doppler radar can detect slow moving objects.

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A Study on Phase noise Reduction Technique in Oscillator Using PBG (PBG를 이용한 Oscillator의 Phase Noise Reduction에 관한 연구)

  • Oh Icsu;Seo Chulhun
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.1
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    • pp.99-103
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    • 2005
  • In this paper, a new technique to reduce the phase noise in microwave oscillators is proposed using the resonant characteristics of the Photonic Bandgap(PBG). We applied PBG structure to ground of the microstrip line resonator with the low Q(Quality factor). Therefore, we improved about 10 dBc in contrast to phase noise characteristic of the conventional microstrip line oscillator at 2.4 GHz @ 100 MHz offset. Output power is 7.09 dBm.

Measurement of Plasma Density Generated by a Semiconductor Bridge: Related Input Energy and Electrode Material

  • Kim, Jong-Dae;Jungling, K.C.
    • ETRI Journal
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    • v.17 no.2
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    • pp.11-19
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    • 1995
  • The plasma densities generated from a semiconductor bridge (SCB) device employing a capacitor discharge firing set have been measured by a novel diagnostic technique employing a microwave resonator probe. The spatial resolution of the probe is comparable to the separation between the two wires of the transmission lines (3 mm). This method is superior to Langmuir probes in this application because Langmuir probe measurements are affected by sheath effects, small bridge area, and unknown fraction of multiple ions. Measured electron densities are related to the land material and input energy. Although electron densities in the plasma generated by aluminum or tungsten-land SCB devices show a general tendency to increase steadily with power, at the higher energies, the electron densities generated from tungsten-land SCB devices are found to remain constant.

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Josephson plasma excitation in vortex states

  • Kadowaki, K.
    • 한국초전도학회:학술대회논문집
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    • v.10
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    • pp.21-21
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    • 2000
  • The Josephson Plasma resonance in single crystalling Bi2Sr2CaCu2O8 has been investigated at a microwave frequency of 35 GHz in a cavity resonator. A sharp resonance is observed in a perpendicular oscillating magnetic field. The former is independent of the sample dimension, shile the latter shift to higher field as the sample size L is reduced, and it disappears when L becomes smaller than the critical length. The longitudinal plasma mode is a Nambu-Goldston mode in a superconductor, the experimental distinction between the longitudinal and the transverse mode leads to the conclusion that the existence of the Nambu-Goldston mod as predicted by Anderson was experimentally confirmed by direct observation of the Josephson plasma resonance with longitudinal excitations. The finite gap found in Josephson plasma resonance also provides a direct proof of the Anderson-Higgs mechanism within the context of the spontaneously broken phase symmetry of the Gauge-field theory in a superconductor.

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A design of a lowpass filter using Quad-Spiral Defected Ground Structure (Quad-Spiral Defected Ground Structure를 이용한 저역통과 여파기 설계)

  • Jeong, Yong-Woo;Kim, Chul-Soo;Park, Kyu-Ho;Ahn, Dal
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.343-346
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    • 2003
  • A new structure to design low pass filters (LPFs) is presented rho proposed structure has the etched shape of Quad-Spiral DGS(Defected Ground Structure) on microstrip transmission lines. By extracting the equivalent circuit elements of unit Quad-Spiral DGS, LPFs are designed easily. The equivalent circuit of Quad-Spiral DGS consists of a step impedance resonator and lumped elements. The proposed LPF provided steep rejection characteristics with 5-poles. Experimental results show excellent agreements with circuit simulation results in wide band and the validity of our circuit modeling for LPF design. The result shows another possibility of Quad Spiral DGS for microwave devices.

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Fabrication of LTCC Tape and Its Microwave Dielectric Properties (LTCC Tape 제조 및 고주파 유전특성 평가)

  • Lee, Kyoung-Ho;Choi, Byung-Hoon;Ahn, Dal;Sung, Jung-Hyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.11b
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    • pp.382-385
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    • 2001
  • In the previous study, a new LTCC material in the PbWO4TiO2B2O3CuO system was introduced. The developed material can be sintered at 850C and its dielectric properties are εr=2025, Q×fo=3000050000GHz, and τf=0.230ppm/C, respectively. Therefore this material can be used as a LTCC substrate material for fabrication of multilayered high frequency communication module set. In present study, using this material, tape casting condition was established. With this condition, a multilayered resonator was fabricated and its electrical properties were examined. In present study, an antenna-duplexer module was also fabricated. Frequency characteristics of as-fabricated antenna-duplexer module was compared with simulation results.

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