• Title/Summary/Keyword: 감쇄 특성

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Computation of Transmissivity and Signal Loss in Inhomogeneous Complex Media (불균일 복합매질의 투과도 및 신호감쇄량 계산)

  • 김채영;정종철
    • Journal of the Korea Institute of Military Science and Technology
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    • v.2 no.1
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    • pp.30-37
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    • 1999
  • Transmissivity and the signal loss in soil are computed. An electric field expression for the inhomogeneous complex media modelled by two layers is shown as an integral form. Volume scattering occurs in inhomogeneous media, and iterative Born approximation is used to analyze this scattering effect. The degree of randomness is controlled by specifying the variance and correlation length. Expression for the transmissivity and the signal loss is presented as the parameter of soil moisture contents, soil particle radius, temperature and frequency. The analysis shows that big deviation in signal loss depends on the temperature variation remarkably and the physical reason of unusual level is explained.

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Design of the Multi-PIN Diode Waveguide Limiter with Extended Attenuation Bandwidth (확장된 신호 감쇄대역을 갖는 다중 PIN다이오드 도파관 리미터 설계)

  • Na, Jae-Hyun;Roh, Don-Suk;Kim, Dong-Gil
    • The Journal of the Korea institute of electronic communication sciences
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    • v.13 no.5
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    • pp.971-978
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    • 2018
  • This paper deals with the design and implementation of a limiter, which is a key component of the Ku-band radar system. The limiter design with the multi-pin diode switch was complemented by wideband signal attenuation, and realized the physical implementation. In the test result of implemented limiter, when the pin diode switch is all off, it is possible to transmit the incoming signal without distortion. Also when the pin diode switch is turned on sequentially, the input signal is attenuated about 20dB or more step by step. Finally when all of them were turned on, attenuation about 50dB or more were measured for a wide bandwidth(1000MHz) in Ku-band.

Analysis of Radio Attenuation Characteristics over 1 to 6 GHz for the Ground Material and Antenna Height in Roadway Open Environment (도로 개방 환경에서 바닥면 재질과 안테나 높이에 따른 1~6 GHz 전파 감쇄 특성 분석)

  • Choi, Jae-Won;Kim, Dong-Woo;Oh, Soon-Soo
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.3
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    • pp.397-404
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    • 2020
  • In this paper, the propagating-wave attenuation characteristics at 1, 3, and 6 GHz in the open environment roadway where the ground-reflected wave dominates are analyzed through a propagation model simulation using a ray-tracing method and propagation measurements. Simulations has been performed by varying the ground material, the transmitting antenna height, and the receiving antenna height. The measurements were conducted using a directional transmission antenna installed at 10 m mast and a omnidirectional receiving antenna installed at 1.5 m mast in an open environment. Comparison of simulation and measurement results confirms that the null points having the weak signal strength depend on those parameters. Although this research has been investigated for the wide road, the derived result could be useful for installing the transmitter and receiver in the roadway open environment.

Design and Fabrication of Deep Attenuation LPF using Meander Microstrip Transmission Line (미앤더 마이크로스트립 전송선을 이용한 고감쇄 LPF 설계 및 제작)

  • Seo, Soo-Duk;Cho, Hak-Rae;Yang, Doo-Yeong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.3
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    • pp.1734-1739
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    • 2014
  • In this paper, microstrip low pass filter using transmission line with the modified DCRLH structure is designed and fabricated to be removed a spurious resonant mode, and a deep attenuation in stop band. The low pass filter is composed of shunt open-stub to get a deep attenuation and series short-stub to eliminate the spurious harmonics in stop band. In this way, the spurious harmonics occurring on the higher order frequency are suppressed and the filter performance is improved. Insertion loss and VSWR of the fabricated microstrip low pass filter in the passband from DC to 1.5 GHz is 1.26 dB and 1.65, and attenuation on the stopband from 1.84 GHz to 2.18 GHz is less than -100 dB. And also this filter has a good performance for 20 watt power test.

Half Wavelength Partial H-Plane Filter with Inverters having Attenuation Poles (감쇄극 인버터를 이용한 반파장 Partial H-Plane 여파기)

  • Kim, Dong-Jin;Lee, Jeong-Hae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.19 no.2
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    • pp.107-113
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    • 2008
  • This paper presents half wavelength partial H-plane filters with multiple attenuation poles using narrow H-plane slot of evanescent waveguide. The narrow H-plane slot operates as an admittance inverter o( the bandpass filter and, simultaneously, generates an attenuation pole at particular frequency. Therefore, proposed filters with attenuation poles are simply implemented without any additional coupling and extra modification of the structure. The number of attenuation poles of the filters equals to that of the H-plane slots. Moreover, proposed filters are compact waveguide filter since ones are embodied by partial H-plane waveguide which has 1/4 cross section of conventional waveguide. The third and fourth-order half wavelength filters having 4 and 5 attenuation poles, respectively, are designed in H-band and their frequency responses are confirmed by simulation and measurement.

광섬유와 그 특성

  • 최상삼
    • 전기의세계
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    • v.30 no.3
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    • pp.146-151
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    • 1981
  • 본고의 내용은 다음과 같다. 1. 광섬유의 구조와 특성 2. Numerical Aperture(NA) 3. 편광현상(Polarization effect) 4. 신호의 감쇄 5. 투과 대여폭(Transmission Bandwidth)

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Measurement of the Indoor Wireless Environment at 2.45 GHz (2.45 GHz 대역 실내 무선 환경 측정)

  • Hwang Jae-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2006.05a
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    • pp.1005-1008
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    • 2006
  • In this paper, we provide data of wireless environment in indoor for Bluetooth and wireless LAN systems. To accurately measure transmission characteristic for influence of the indoor wall, we used radiation measurement system with antennas. And various structure and material of the indoor wall are measured. Results of the measurement show that the attenuation of power is about $1\sim3dB$ for cement wall(25cm). In the case of cement wall with steel frame, the attenuation of power was increased using horizontal polarization but was not affect using vertical polarization.

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Dynamic Responses in Ultra-Soft Magnetic Thin Films (초 연자성 박막에서의 동적 자화 거동)

  • 정인섭
    • Journal of the Korean Magnetics Society
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    • v.4 no.1
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    • pp.1-6
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    • 1994
  • The magnetization dynamics was investigated by solving possible origins of overdamped susceptibility observed in ultra-soft magnetic amorphous thin films. The experimental high frequency spectrum and computational spectrum calculated from Gilbert's equation of motion were compared in order to find proper damping factor $\alpha{\approx}20$ and demagnetizing coefficients $D_{x}{\approx}D_{y}{\approx}D_{z}{\approx}0$ for ultra-soft magnetic films. A magnetization vortex mode was, then, proposed to explain the origin of the reversible susceptibility and other anomalies of the ultra-soft magnetic heterogeneous thin films. In this mode it is suggested that there occur, within the nanoscale structural features of the ultra-soft films, incoherent rotational spin motions that are highly damped by the energy transfer from short wavelength spin wave modes and local defect structure mode interactions.

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A design of the linearly controlled CMOS Attenuator (선형제어가 가능한 CMOS 가변 감쇄기의 설계)

  • 송윤섭;김재민;김수원
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.4A
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    • pp.458-465
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    • 2004
  • To reaffirm the use of a mainstream CMOS process for designing passive-like attenuator structures, a linearly controlled variable attenuator is realized with 0.35${\mu}{\textrm}{m}$ 2-poly 4-metal CMOS process. It uses the П configuration for large attenuation range and suitable matching property. Compared to conventional passive-like CMOS attenuators, it is demonstrated that this work advances the frequency band from MHz to ㎓ (DC- l㎓), and reduces the size to 700${\mu}{\textrm}{m}$${\times}$300${\mu}{\textrm}{m}$.. Both simulation results and test results are provided. They show the improved linear relation between attenuation and control voltage. It is very useful in CDMA or GSM band, which uses under 1㎓ frequency band. An alternative topology, Bridged-T configuration, is proposed to get over the limit of applications by elevating operation bandwidth. The proposed topology covers over DC-2㎓ frequency band, which means that the proposed architecture can cover the tripleband (800MHz CDMA/GSM, 1.5㎓ GPS, 1.9㎓z PCS system) in applications as well. The simulation results are provided.

A Design of the Dielectric Resonator BandPass Filters with attenuation poles for the PCS Channel Combiner (PCS Channel Combiner 구현을 위한 감쇄극을 갖는 유전체 공진기 대역통과 여파기의 설계)

  • Kang, Hyun-Taek;Myung, Sung-Ho;Kim, Chul-Soo;Park, Jun-Seok;Ahn, Dal;Park, Jong-Chul;Park, Sung-Yuel;Kim, Geun-Young
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.37 no.4
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    • pp.52-58
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    • 2000
  • In this paper, the novel dielectric resonator bandpass filter for Korea personal communication service channel combiner is proposed. The equivalent circuit of the channel bandpass filter is derived using the lumped elements. Proposed channel bandpass filter provides compact size, low insertion loss, two attenuation poles in the stop band, and excellent temperature characteristics. Two channel filters are combined with proposed dielectric resonator filter configuration to implement the 2-channel combiner. Experimental results show the validity of the proposed dielectric resonator channel bandpass filter.

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