• Title/Summary/Keyword: Wide-Band

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A Wide Band Antenna Design using the Synthesis of Independent Dual Resonance Modes for Manpack SDR(Software Defined Radio) (독립적인 이중 공진 모드 합성을 이용한 광대역 SDR 무전기 안테나 설계)

  • Yu, Byunggil;Dong, Moo-Ho;Cho, Ji-Haeng;Han, Sung-Woo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.17 no.1
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    • pp.57-63
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    • 2014
  • In this paper, we have proposed a wide band antenna for manpack SDR(Software Defined Radio). The proposed antenna consists of feeding post, flexible gooseneck and two radiating elements composed of a upper and lower radiators. The upper radiator has a longer electrical length than the lower radiator in order to operate in the lower frequency. Also, the resonant frequency and impedance characteristics of the antenna can be adjusted independently for two radiators. Therefore, the proposed antenna can be achieved wide impedance bandwidth by the combination of two independent resonance modes. To analyze the characteristics of the antenna in the design process is employed the equivalent circuit theory and EM(Electro-Magnetic) simulation. The measurement results show that the proposed antenna have the sufficient wide bandwidth, above -3.4dBi of the gain and fairly good radiation pattern over the wide bandwidth.

A Proper Design of Parabolic Antenna according the Up-grade to Wide-band Loading (대역폭 증가에 따른 포물선 안테나의 설계)

  • Son, Hyun;Kim, Ki-Wan
    • 전기의세계
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    • v.25 no.6
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    • pp.69-73
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    • 1976
  • Thd idle channel noise on FDM-microwave communication system is increasing because of the up-grade to wide-band loading. The thermal noise on receiver of microwave radio is measured according to their channel slot frequencies, low, meddle and high slots on the base band, from 60 channels to 960 channels. And suggested a consideration for system engineering, to reduce the thermal noise from radio microwave receivers, so as to improve signal to noise ratio.

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Design of Wide Band VHF Microstrip Tunable Band-Pass Filters (광대역 VHF 마이크로스트립 가변대역통과 여파기의 설계)

  • 박병호;정용채;윤상원;장익수
    • Journal of the Korean Institute of Telematics and Electronics A
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    • v.29A no.10
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    • pp.24-28
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    • 1992
  • A new design method of microstrip wide band VHF tunable bandpass filters using varacter diodes is presented. In the proposed filter both the input and output ports are coupled through capacitors, and an open micro-strip line is inserted between the coupled line in order to obtain the desired degree of coupling. The optimized filter responseses for the frequency range of 220-404MHz by TOUCH-STONE are compared with the measured ones.

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Design of Ultrawide Band Monopole Antenna (광대역 모노폴 안테나 설계)

  • 이종필;박성욱
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2001.11a
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    • pp.136-139
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    • 2001
  • In this paper, we propese a novel wide band printed monopole antenna called the staircase bow-tie monopole antenna (SBMA). We apply an extraordinarr method for an impedance matching to conventional bow-tie monopoles. So we get the SBMA with a very wide band. Our antenna is smaller than a quarter wavelength in size but provides a 2:1 VSWR bandwidth of about 77.8%. An antenna gain and a radiation pattern are about 1.7dBi and omni-directional at 1.7 GHz, respeotively.

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Performance of Double Binary Turbo Code for Ultra Wide-Band Systems with Multiple-Antenna Scheme (다중 안테나 개념을 적용한 초광대역 무선통신 시스템에서 이중 이진 터보 부호 성능)

  • Kim, Eun-Cheol;Cha, Jae-Sang;Lee, Chong-Hoon;Kang, Jeong-Jin;Kim, Seong-Kweon;Hwang, Sung-Ho;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.9 no.2
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    • pp.117-122
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    • 2009
  • In this paper, the performance of double binary turbo code is analyzed and simulated in ultra wide-band (UWB) systems employing multiple-antenna scheme. We consider both pulse position modulation-time hopping (PPM-TH) and pulse amplitude modulation-direct sequence (PAM-DS) UWB systems. The space time block code (STBC) scheme is adopted as a transmit diversity method. Also, receive diversity scheme is applied. And double binary turbo code is applied to the UWB system.

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A New Space Vector Random PWM Scheme for Induction Motor Drives

  • Kim Hoe-Geun;Na Seok-Hwan;Lim Young-Cheol;Jung Young-Gook
    • Proceedings of the KIPE Conference
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    • 2001.10a
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    • pp.160-168
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    • 2001
  • The RPWM (Random· Pulse Width Modulation) is a switching technique to spread the voltage and current harmonics over a wide frequency area. By using randomly changing switching frequency of the inverter, the power spectrum of the electromagnetic acoustic noise can be spread to the wide-band area. The wide­band noise is much more comfortable and less annoying than the narrow-band one. So, the RPWM has been attracting interest as an excellent method for the reduction of acoustic noise on the inverter drive system. In this paper a new RPPWM (Random Position Space Vector PWM) is proposed and implemented. Each of three phase pulses is located randomly in each switching interval. Along with the randomization of PWM pulses, the space vector modulation is also executed in the C167 micro-controller. The experimental results show that the voltage and current harmonics are spread to a wide band area and that the audible switching noise is reduced by the proposed RPPWM method.

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Performance of Rake Receiver for Pulse Position Modulation-Time Hopping Ultra Wide Band Systems in Indoor Environments (실내 환경의 펄스 위치 변조-시간 도약 초광대역 무선통신 시스템에서 레이크 수신기 성능)

  • Kim, Joo-Chan;Kim, Jin-Young
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.3
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    • pp.179-184
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    • 2010
  • In this paper, we analyze and simulate the performance of RAKE receiver for ultra wide band (UWB) systems in indoor multipath radio channel. Pulse position modulation-time hopping (PPM-TH) signal is considered. And we also consider three types of RAKE receivers, which are ideal RAKE, selective RAKE, and partial RAKE receivers. The indoor channel is modeled as the modified Saleh and Valenzuela (SV) model which has been proposed as a UWB channel model by the IEEE group, IEEE 802.15.SG3a.

Fatigue Damage Estimation of Wide Band Spectrum Considering Various Artificial Neural Networks (다양한 인공 신경망을 적용한 광대역 스펙트럼의 피로손상 예측)

  • Park, Jun-Bum;Kim, Sung-Yong
    • Journal of Ocean Engineering and Technology
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    • v.30 no.5
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    • pp.341-348
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    • 2016
  • The fatigue damage caused by wide band loadings has generally been predicted using fatigue damage models in the frequency domain rather than a rain-flow counting method in the time domain because of its computation cost. This study showed that these fatigue damage models can be simplified in the form of normalized fatigue damage as a function of the S-N curve slope and bandwidth parameters. Based on numerical simulations of various wide band spectra, it was found that fatigue damage models in the form of normalized fatigue damage with one S-N curve slope and two bandwidth parameters( α1 , α2 ) provided less reasonable fatigue damage. Therefore, an additional bandwidth parameter needs to be considered based on a sensitivity study using various neural networks, which proved that α1-5 would be the dominant factor of a fatigue damage model as an additional bandwidth parameter.

The Design and Implementation of a Multi-Band Planar Antenna for Cellular/PCS/IMT-2000 Base Station (셀룰러/PCS/IMT-2000 기지국용 다중대역 평판 안테나 설계 및 구현)

  • 오경진;김봉준;최재훈
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.8
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    • pp.781-787
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    • 2004
  • In this paper, a novel dual and wide band aperture stacked patch antenna for Cellular/PCS/IMT-2000 base station is presented. It consists of single microstrip patch having notches along the radiating patch, two dielectric substrates and a form material. To achieve wide band characteristic, we utilize the coupling effect between the notched patch and the resonant aperture in the ground plane and by properly cutting notches on the patch, an aperture stacked patch antenna could be designed to yield dual frequency operation. By the proper choice of resonant aperture size and height of a foam material, dual and wide band characteristic could be realized the measured impedance bandwidth(1:1.5 VSWR) of designed antenna at lower band(860 MHz) reaches 77 MHz and covers the Cellular CDMA band(824∼894 MHz). The measured impedance bandwidth(1:1.5 VSMR) of the designed antenna at upper band(1,960 MHz) is about 550 MHz and covers both the PCS band(1,750∼l,870 MHz) and the for-2000 band(1,920∼2,170 MHz). Good broadside radiation with high gain(5.65∼7.4 dBi) characteristics have also been observed.

Dual-wide-band absorber of truncated-cone structure, based on metamaterial

  • Kim, Y.J.;Yoo, Y.J.;Rhee, J.Y.;Kim, K.W.;Park, S.Y.;Lee, Y.P.
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.235.1-235.1
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    • 2015
  • Artificially-engineered materials, whose electromagnetic properties are not available in nature, such as negative reflective index, are called metamaterials (MMs). Although many scientists have investigated MMs for negative-reflective-index properties at the beginning, their interests have been extended to many other fields comprising perfect lenses. Among various kinds of MMs, metamaterial absorbers (MM-As) mimic the blackbody through minimizing transmission and reflection. In order to maximize absorption, the real and the imaginary parts of the permittivity and permeability of MM-As should be adjusted to possess the same impedance as that of free space. We propose a dual-wide-band and polarization-independent MM-A. It is basically a triple-layer structure made of metal/dielectric multilayered truncated cones. The multilayered truncated cones are periodically arranged and play a role of meta-atoms. We realize not only a wide-band absorption, which utilizes the fundamental magnetic resonances, but also another wide-band absorption in the high-frequency range based on the third-harmonic resonances, in both simulation and experiment. In simulation, the absorption bands with absorption higher than 90% are 3.93 - 6.05 GHz and 11.64 - 14.55 GHz, while the experimental absorption bands are in 3.88 - 6.08 GHz and 9.95 - 13.84 GHz. The physical origins of these absorption bands are elucidated. Additionally, it is also polarization-independent because of its circularly symmetric structures. Our design is scalable to smaller size for the infrared and the visible ranges.

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