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Son, Tae-Ho;Han, Seog-Tae
- The Journal of Korean Institute of Electromagnetic Engineering and Science
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- v.19 no.6
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- pp.640-646
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- 2008
Design procedure of corrugated horn antenna for the mm-wave frequency range is presented, and hybrid condition in horn is calculated. In this paper, corrugate profiles of horn which satisfy both transition to balanced hybrid condition and fabrication possibility under the mm-wave short wavelength are obtained. Electromagnetic fields inside horn and corrugation are derived by the cylindrical mode theory. Propagation characteristics in the horn are calculated by the mode impedance matching method with boundary conditions, and radiation fields are obtained by the Kirchhoff-Hyugen principle to the horn aperture fields. A mm-wave corrugated horn antenna which operates on $85{\sim}115GHz$ is fabricated by electric forming method. Measurements show that VSWR is under 1.3:1 over whole band and the half power beamwidth on radiation pattern 9.2, 9.16 and 9.02 degree on 85, 100 and 110 GHz are agree well with theoretical calculation.
https://doi.org/10.5515/KJKIEES.2008.19.6.640 인용 PDF KSCI

Yun, Eui-Jung;Lee, Gang-won;Kim, Chol-Ho;Lee, Seok-Tae
- Journal of the Korean Institute of Electrical and Electronic Material Engineers
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- v.17 no.12
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- pp.1259-1263
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- 2004
In this paper, the optimum design of ultrasonic dry cleaning head was investigated. The transducer instead of mechanical dynamic structure was used to generate ultrasonic wave and the horn-shape amplifier was utilized to solve the energy decaying problem of ultrasonic wave with propagating it through the media. The analyses of ultrasonic wave and a fluid for the selected structure of a cleaning head were carried out using SYSNOISE and ANSYS simulators, respectively. Based on simulator results, the distance between a horn and the substrate of 4 mm and the horn diameter of 10 mm were determined to maximize the energy of ultrasonic waves. The cooling structure was also considered to reduce the heat from the transducer and the horn. The equivalent circuit for the fabricated horn was deduced from HP4194A impedance/gain/phase analyzer and the frequency of an ultrasonic wave of 20.25 kHz was confirmed using the parameters of the equivalent circuit.
https://doi.org/10.4313/JKEM.2004.17.12.1259 인용 PDF KSCI

Jeon, S.M.;Mun, J.M.;Lee, S.C.;Sim, K.D.;Kim, S.H.
- Progress in Superconductivity and Cryogenics
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- v.24 no.1
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- pp.29-33
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- 2022
Recently, development of a cryogenic fluids storage tank for storing or transporting liquid hydrogen is actively in progress. In cryogenic fluids storage tanks, hydrogen evaporates due to the extreme temperature difference inside and outside the tank. As the mass of the cryogenic fluids changes with continuous vaporization, the fluids level also changes. Therefore, there is need for a method of accurately measuring the level change in the storage tank. In the case of general cryogenic fluids, it is difficult to accurately measure the level because the dielectric constant is very low. As a method of measuring cryogenic fluids level with low dielectric constant, it can be used an Millimeter wave (MM wave) FMCW radar sensor. However, the signal sensitivity is very weak and the level accuracy is poor. In this paper, the signal sensitivity is improved by designing the horn lens antenna of the existing 80 GHz FMCW radar sensor. Horn lens antenna is fabricated by FDM/SLA type 3D printer according to horn and lens characteristics. The horn is used to increase the signal gain and the lens improves the signal straightness. This makes it possible to measure the level of cryogenic fluids with a low dielectric constant.
https://doi.org/10.9714/psac.2022.24.1.029 인용 PDF KSCI