• Title/Summary/Keyword: Waveguide

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Modal Analysis of Rectangular MQW Waveguide : A Novel Approach using Scanning Angle Method (직사각형 다중 양자 우물 도파관의 모드특성 분석 : Scanning angle method를 사용한 새로운 접근)

  • Im, Yeon-Seop;Choe, Yeong-Wan
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.37 no.4
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    • pp.45-52
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    • 2000
  • We present a novel method for simple and efficient analysis of the rectangular MQW waveguide. Preferentially two-dimensional structure is transformed into one-dimensional structure by using the effective index method. Then, the characteristic matrix of the resultant planar MQW waveguide is analyzed by scanning angle method. The effective index, modal intensity, and optical confinement factor of rectangular MQW waveguide can be effectively obtained by this method. Our simulation results show excellent agreement with the accurate solutions based on the finite element method. We also introduce the approximation methods for the analysis of rectangular MQW waveguide and investigate their validity. By using perturbation approach, modal power loss of guided wave in rectangular MQW waveguide is newly investigated and compared with the conventional method using the approximation of planar MQW waveguide.

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Evaluation of Air Flow Characteristics in accordance with Types of Waveguide-Below-Cutoff (WBC) Arrays and Their Shielding Effectiveness of Electromagnetic Pulse (EMP) (EMP 차폐를 위한 도파관 형상과 SE에 따른 유동 특성 평가)

  • Pang, Seung-Ki;Ahn, Hye-Rin;Yook, Jong-Gwan
    • Journal of the Korean Society for Geothermal and Hydrothermal Energy
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    • v.12 no.3
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    • pp.1-8
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    • 2016
  • In this study, we evaluated the flow characteristics of various types of waveguide-below-cutoff (WBC) arrays and their shielding effectiveness (SE) of electromagnetic pulses (EMP) based on computational fluid dynamics (CFD). Three types of waveguides were selected for analysis: (1) grid type, (2) honeycomb type, and (3) multi-layer types (2-ply, 4-ply, 6-ply, and 8-ply). To analyze the air flow characteristics, the flow velocities in the longitudinal center of the WBC and the differential pressures between the WBC array inlet and outlet were evaluated. Consequently, we derive the following conclusions: (1) despite an increase in the inlet velocity, the pressure drop of the 6-ply multi-layer type did not significantly increase as compared to that of other types of waveguides (waveguide thickness of 0.1 mm, SE of 100 dB); (2) the grid and honeycomb type had the fastest flow rate of 17.5 m/s, which is approximately 2.5 m/s faster than that at the inlet (waveguide thickness of 1 mm, module size of 30 mm); and (3) the average pressure drop of the grid type waveguide is the lowest in the overall model, whereas that of the 8-ply is the highest (waveguide thickness of 1 mm, module size of 30 mm, and SE of 80, 100 dB).

60GHz band RF transceiver of the broadband point-to-point communication system (광대역 점대점 통신시스템용의 60GHz 대역 무선 송수신기)

  • Choi, Jae-Ha;Yoo, Young-Geun
    • Journal of the Institute of Convergence Signal Processing
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    • v.13 no.1
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    • pp.39-43
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    • 2012
  • 60GHz band RF transceiver was made with the NRD waveguide structure for the point- to-point communication. A dielectric line that of comprising NRD waveguide was the milling process was not easy because a material gets soft, and also compression and expansion according to a temperature were serious, so this line was not suitable for the device in which the resonance characteristic was important. In addition, the thing for comprising amplification module was difficult in the NRD waveguide structure. In this paper, a way in which to overcome mentioned in upper part, the transceiver was made by below technology. Components in which the resonance characteristic was not important were made with the NRD waveguide hybrid IC, and components in which the resonance characteristic was important were made with waveguide. An amplifier packaged and modularizing the bare chip, it equipped at the NRD waveguide within. Manufactured transceiver communicated with FDD method, and it had 10dBm output power, and -60dBm minimum receive sensitivity.

A Numerical Method for Analysis of the Sound and Vibration of Waveguides Coupled with External Fluid (외부 유체와 연성된 도파관의 진동 및 소음 해석 기법)

  • Ryue, Jung-Soo
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.7
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    • pp.448-457
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    • 2010
  • Vibrations and wave propagations in waveguide structures can be analysed efficiently by using waveguide finite element (WFE) method. The WFE method only models the 2-dimensional cross-section of the waveguide with finite elements so that the size of the model and computing time are much less than those of the 3-dimensional FE models. For cylindrical shells or pipes which have simple cross-sections, the external coupling with fluids can be treated theoretically. For waveguides of complex cross-sectional geometries, however, numerical methods are required to deal with external fluids. In this numerical approach, the external fluid is modelled by the boundary elements (BEs) and connected to WFEs. In order to validate this WFE/BE method, a pipe submerged in water is considered in this study. The dispersion diagrams and point mobilities of the pipe simulated are compared to those that theoretically obtained. Also the acoustic powers radiated from the pipe are predicted and compared in both cases of air and water as an external medium.

Optical waveguide structure design of Non-dispersive Infrared (NDIR) CO2 gas sensor for high-sensitivity (이산화탄소 검출을 위한 고감도 비분산 적외선 가스센서의 광도파관 구조 설계)

  • Yoon, Jiyoung;Lee, Junyeop;Do, Namgon;Jung, Daewoon
    • Journal of Sensor Science and Technology
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    • v.30 no.5
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    • pp.331-336
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    • 2021
  • The Non-dispersive Infrared (NDIR) gas sensor has high selectivity, measurement reliability, and long lifespan. Thus, even though the NDIR gas sensor is expensive, it is still widely used for carbon dioxide (CO2) detection. In this study, to reduce the cost of the NDIR CO2 gas sensor, we proposed the new optical waveguide structure design based on ready-made gas pipes that can improve the sensitivity by increasing the initial light intensity. The new optical waveguide design is a structure in which a part of the optical waveguide filter is inclined to increase the transmittance of the filter, and a parabolic mirror is installed at the rear end of the filter to focus the infrared rays passing through the filter to the detector. In order to examine the output characteristics of the new optical waveguide structure design, optical simulation was performed for two types of IR-source. As a result, the new optical waveguide structure can improve the sensitivity of the NDIR CO2 gas sensor by making the infrared rays perpendicular to the filter, increasing the filter transmittance.

A Study on the Fabrication LiNbO3 Optical Waveguide (LiNbO3 광도파로 제작에 관한 연구)

  • Kim, Sun-Yeob
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.9
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    • pp.6221-6226
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    • 2015
  • In this paper, waveguide analysis was interpreted as an optical waveguide using the feedback perturbation method simple and easy to apply compared to the analysis method, while the other almost identical to the numerical calculation method. In addition, efficient coupling with an optical transmission line of optical fiber and the waveguide form the thin film of different functional elements is required in order to achieve the full optical communication system. However, problems arise, such as the light field (field) and the decrease of the access efficiency due to inconsistency in the distribution characteristics of the connection surface by the difference in size of the cross section thereof when connecting the optical fiber and the waveguide directly to the combination of a thin film. Therefore propose a new type of connector structure to increase the efficiency of the connection when connecting the optical fiber waveguide and the thin film was analyzed by applying a coupled mode theory, the binding efficiency of the modified contactor. And by diffusing Ti on the $LiNbO_3$ substrate and a wide range of applications in the manufacture of integrated optical material made of a current low-loss Ti: $LiNbO_3$ optical waveguide and making the Y-branch waveguide, and the properties were confirmed.

Investigation of Planar Optical Waveguide Formed by MeV $He^{+}$ Ion-Implantation into NaEr(WO$_4$)$_2$ Crystal

  • Feng Chen;Wang, Xue-Lin;Wang, Ke-Ming;Cheng, Zhen-Xiang;Chen, Huan-Chu;Shen, Ding-Yu
    • Journal of Korean Vacuum Science & Technology
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    • v.6 no.2
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    • pp.97-100
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    • 2002
  • NaEr(WO$_4$)$_2$ is a new laser material. The planar optical waveguide was formed in NaEr(WO$_4$)$_2$ crystal by 2.6 MeV He$^{+}$ ion implantation at doses of 1.0-1.5 $\times$ 10$^{16}$ ions/cm$^2$ at room temperature. The effective refractive indices of the dark modes were measured using the prism coupling method. foul n modes and five TM modes were observed in the waveguide. The refractive index profiles were analyzed using the reflectivity calculation method (RCM). The influence of heat treatment at moderate temperature on the refractive index profiles of the waveguide was also investigated. We used the TRIM'98 (Transport of ton in Matter) code to simulate the damage profile in the NaEr(WO$_4$) crystal by 2.6 MeV He$^{+}$ion implantation which is helpful for a better understanding of the waveguide formation.ion.

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Analysis of Scattering Characteristics of a Rectangular Waveguide with Conducting Half Cylinders using the Mode Matching Method (모드매칭법을 이용한 금속의 Half Cylinder가 있는 구형 도파관의 산란 특성 해석)

  • 김원기;천동완;김상태;신철재
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.8A
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    • pp.962-971
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    • 2004
  • In this paper, we present the numerical analysis method for analyzing scattering characteristics of a rectangular waveguide with the conducting half cylinder using the mode matching method and compute scattering characteristics of a waveguide according to the rotation and changing radius of the half cylinder. Also, in conjunction with the generalized scattering method, the proposed method can be easily applied to a rectangular waveguide with cascade structure of conducting half cylinders. From the simulated result of a two pole filter, resonance frequency could be controlled by the rotation of half cylinders. The simulated result shows good agreement with the HFSS's result. The proposed structure and analysis method are easily applied to the design of waveguide components with conducting half cylinders.

A Novel Epsilon Near Zero Tunneling Circuit Using Double-Ridge Rectangular Waveguide

  • Kim, Byung-Mun;Son, Hyeok-Woo;Hong, Jae-Pyo;Cho, Young-Ki
    • Journal of electromagnetic engineering and science
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    • v.14 no.1
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    • pp.36-42
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    • 2014
  • In this paper, an epsilon near zero (ENZ) tunneling circuit using a double-ridge rectangular waveguide (RWG) is proposed for the miniaturization of a waveguide component. The proposed ENZ channel and is located in the middle of the input-output RWG (IORWG). The ratio of the height to the width of the channel waveguide is very small compared to the IORWG. By properly adjusting the ridge dimensions, the tunneling frequency of the proposed ENZ channel can be lowered to near the cut-off frequency of the IORWG. For the proposed ENZ tunneling circuit, the approach adopted for extracting the effective permittivity, effective permeability;normalized effective wave impedance, and propagation constant from the simulated scattering parameters was explained. The extracted parameters verified that the proposed channel is an ENZ channel and electromagnetic energy is tunneling through the channel. Simulation and measurement results of the fabricated ENZ channel structure agreed.