• Title, Summary, Keyword: Insertion Loss

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An Optimal Design of the Compact CRLH-TL UWB Filter Using a Modified Evolution Strategy Algorithm

  • Oh, Seung-Hun;Wu, Chao;Chung, Tae Kyung;Kim, Hyeong-Seok
    • Journal of Electrical Engineering and Technology
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    • v.10 no.2
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    • pp.653-658
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    • 2015
  • This paper deals with an efficient optimization design method of a compact ultra wideband (UWB) filter which can improve the characteristics of the filter. The Evolution Strategy (ES) algorithm is adopted for the optimization and modified to suppress the ripple by inserting an additional step to the ES scheme. The algorithm has the ability to control the ripple of an insertion loss in a passband as a modified approach. During the modified ES, a structure of initial shape is changed a lot, while includes the stepped impedance (SI) and the composite right/left handed transmission line (CRLH-TL). And an optimized filter satisfies the UWB specifications on the stopband and passband with an acceptable insertion loss. The filter achieves a much developed shape, the size of $15{\times}14mm$, the 3dB bandwidth from 2.7 to 10.8GHz, the flat insertion-loss less than 1dB, the wide stopband with 12~20GHz, and an acceptable return loss.

An Insertion Loss Analysis of Partially Inclined Noise barrier (상단부가 꺾인 방음벽의 삽입손실해석)

  • Chin Byung-Joo;Kim Hyun-Sil
    • Proceedings of the Acoustical Society of Korea Conference
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    • pp.411-414
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    • 1999
  • Insertion loss of partially Inclined noise harrier Is studied by using multiple diffraction theory. The diffractions occurred at the top as well as partially folded point are included based on Kouyoumjian and Pathak's method (Procd. IEEE, Vol. 62, 1974). Scaled-down model of noise barrier is studied in anechoic rooom. It is shown that the theoretical results generally represents the average values of experimental results, while there are many oscillations in experimental results.

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A Study on Microstrip Patch Array Antenna Integrated on SIW Network for SoS (SoS를 위한 SIW 망에 집적된 마이크로스트립 패치 어레이 안테나에 관한 연구)

  • Ki, Hyeon Cheol
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.18 no.5
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    • pp.63-68
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    • 2018
  • In this paper, We intended to design various things for the realization of SoS(System on Substrate) with SIW in 24GHz ISM 밴드(24-24.25GHz). As part of them, We integrated SIW, transition and MPAA as SoS on the same substrate and investigated its characteristics. We used Rogers Ro4350 with relative permittivity of 3.48 and thickness of 20mil. As results of optimal design, insertion loss of the SIW with 11.55mm length showed 0.32dB and insertion loss of 0.19dB occurred in transition to $50{\Omega}$ microstrip. Characteristics of the MPAA integrated on the same substrate as SoS are very similar to those of stand-alone MPAA. But the integrated MPAA decreased by 0.58dB in gain, which is the sum of SIW insertion loss and transition insertion loss, and by 0.7dB in SLL compared that of stand-alone MPAA. However, the bandwidth was increased by 19.4% as it changed from 670MHz to 800Mhz.

A Study on the Insertion Loss of Noise Barrier with the Variation of Top Shape (방음벽 상단부 형상에 따른 삽입손실 연구)

  • 정성수;김용태;이우섭
    • The Journal of the Acoustical Society of Korea
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    • v.21 no.7
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    • pp.624-631
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    • 2002
  • The insertion loss of the noise barriers with several top shape is measured in an anechoic room by using a reduced scale model test. The insertion loss differences between a straight vertical barrier having 0.3 m height and several barriers with simple top shaped are compared. The results show that the latter is more effective than the former and absorptive barrier is more effective than the reflective one. Among the barrier types of 'T', 'Y', and '(equation omitted)', type 'Y' is the best one and the rest have similar effect. This result is well agree with Alfredson (PIOC. Inter-Noise 95, p. 381, 1995)'s but contradict to May (J. Sound Vb. 71, p. 73, 1980)'s. Therefore, it is difficult to determine which type is the best. In order to find out this discrepancy, boundary element method is adopted and the result shows one can have different result because each supposed different experimental conditions like height of noise barrier, positions of sound source and receiver, etc.

Evaluation of Noise Reduction Performance of HVAC System for Ships (선박용 HVAC 시스템의 소음저감성능 평가)

  • Kim, Sang-Ryul;kim, Hyun-Sil;Kim, Jae-Seung;Kim, Bong-Ki;Lee, Sung-Hyun
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.8
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    • pp.497-503
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    • 2010
  • In this paper, evaluation of noise reduction performance of HVAC system for ships by means of HVAC mock-up system is presented. Test is done for six different types of HVAC elements including room unit, silencer, etc. It is found that when diameter of silencer is small and air flow is large, flow noise degrades insertion loss. However, as diameter of silencer becomes larger, the effect of flow noise becomes smaller, and insertion loss up to 25 dB is measured. It is observed that insertion loss of diffuser type room unit is usually between zero and 10 dB, whereas that of the nozzle type room unit can be down to - 15 dB. In addition, it is shown that changing duct arrangement can reduce cabin noise by up to 2 dB, and providing same air flow to each room unit is crucial for generating less noise.

Fabrication of the Micromachined Transformer based on Air Core for the Application of Wireless Power Transmission (무선전력전송을 위한 에어 코어 기반의 트랜스포머 제작)

  • Kim, Sung-Tae;Cha, Doo-Yeol;Kang, Min-Suck;Cho, Se-Jun;Jang, Sung-Pil
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.1
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    • pp.1-6
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    • 2009
  • Air core based transformers have been designed, simulated and fabricated by using micromachining process for the application of wireless power transmission with the range of frequency from 1 GHz to 20 GHz. Fabricated transformers are the types of solenoid transformers with primary and secondary coils. the size of fabricated transformer is $1.1{\times}1.5{\sim}2.15\;mm$ including ground shield. Transformers have been measured by dividing two groups based on the turns ratio between primary coil and secondary coil which are 1:1 transformers(the number of turns of primary coil and secondary coil: 3/3, 5/5, 7/7) and l:n transformers(the number of turns of primary coil and secondary coil: 3/3, 3/6, 3/9). As a result of the measurement, the lowest insertion loss of transformers ranged from 2 dB to 2.8 dB according to the number of turns between primary coil and secondary coil. And the lowest insertion loss from the transformers was measured at the frequency from 7 GHz to 11 GHz according to the number of turns between primary coil and secondary coil. Based on the measurement data from the microfabricated transformers, the transformer with the 3/3 turns in the primary coil and secondary coil showed best performance compared to others in terms of lowest insertion loss, lowest insertion loss frequency and bandwidth.

Acoustic insertion loss by a bubble layer for the application to air bubble curtain and air masker (기포층 음향 삽입손실 연구: 기포커튼과 에어마스커)

  • Park, Cheolsoo;Jeong, So Won;Kim, Gun Do;Moon, Ilsung;Yim, Geuntae
    • The Journal of the Acoustical Society of Korea
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    • v.39 no.4
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    • pp.227-236
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    • 2020
  • This paper derives the insertion loss for the bubble layer of an air bubble curtain and an air masker which are used to reduce ocean anthropogenic noise such as the piling noise and the ship noise. The air bubble curtain is considered as a 'fluid-air bubble layer-fluid' model and the environment for the air masker is simplified as an 'vacuum-thin plate-fluid-air bubble layer-fluid' model. The air bubble layer in each model is assumed as the effective medium which has the complex wavenumber and the complex impedance corresponding to the bubble population distribution. The numerical simulations are performed to examine the insertion loss depending on the bubble population, the void fraction, and the thickness of the layer.

Design of The Suction Muffler of a Reciprocating Compressor (왕복동식 압축기 흡입머플러 설계)

  • Lee, Jeong-Ho;An, Kwang-Hyup;Lee, In-Seop
    • Proceedings of the KSME Conference
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    • pp.337-340
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    • 2001
  • The suction muffler of a reciprocating compressor is used for reducing noise produced by pressure pulsations. According to the shape, the suction muffler is classified into one-chamber type, two-chamber type, Helmholtz resonator type, pipe-resonator type, and so on. These mufflers are used according to the characteristics of the frequency of compressor noise. In this study, four pole parameters have been used for calculating Transmission Loss of the muffler, and Insertion Loss has been acquired for the optimum design of the muffler by the experiment.

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Design and Implementation of a Ku-band Packaged 5-bit Phase Shiner (패키지된 KU-밴드용 5-비트 위상변위기 설계 및 제작)

  • 장우진;형창희;이희태;이경호;송민규
    • Proceedings of the IEEK Conference
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    • pp.21-24
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    • 2000
  • This paper introduces the design and implementation of a Ku-band 5-bit monolithic phase shifter with a ceramic package. The 5-bit phase shifter MMIC was designed and fabricated by using GaAs MESFET switches. The packaged phase shifter demonstrates a phase error less than 11.3 $^{\circ}$ RMS and an insertion loss variation less than 1.0㏈ RMS for 13∼15㎓. For all 32 states, an insertion loss is measured to be 12.2${\pm}$2.2㏈, an input return loss more than 5.0㏈, and an output return loss more than 6.2㏈ from 13㎓ to 15㎓. The chip size of the 5-bit phase shifter MMIC is 2.35${\times}$1.65mm$\^$2/ including digital control circuits. The size of the ceramic packaged phase shifter is 7.2${\times}$6.2mm$\^$2/.

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Film Bulk Acoustic Resonator(FBAR) using Bragg Reflector for IMT-2000 Bandpass Filter (Bragg 반사층을 이용한 IMT-2000 대역통과필터용 체적 탄성파 공진기)

  • 김상희;김종헌;박희대;이시형;이전국
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.377-382
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    • 2000
  • Film bulk acoustic resonator (FBAR) using AIN reactively sputtered at room temperature was fabricated. The FBAR is composed of a piezoelectric aluminium nitride thin film, top electrode of Al and bottom electrode of Au connected by a short (200${\mu}{\textrm}{m}$) transmission line on both sides and reflector layers of SiO$_2$- W Pair. The active areas of Al and Au were patterned using 150${\mu}{\textrm}{m}$ diameter shadow mask. The series resonance frequency (fs) and the parallel resonance frequency (fp) were measured at 1.976 GHz and 2.005 GHz, respectively. The minimum insertion loss and return loss were 6.1 dB and 37.19 dB, and the quality factor (Q) was 4261.

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