• 한국산학기술학회논문지
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• 제16권10호
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• pp.6839-6845
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• 2015

본 논문에서는 다수의 안테나가 필요한 다양한 기능의 광대역 무선 통신 시스템을 한 개의 안테나로 구현하기 위한 슬리브 모노폴 안테나의 광대역 특성 최적화 설계 방법을 제시하였다. 이를 위하여 슬리브 모노폴 안테나의 슬리브 부분이 개방형 스터브로 동작한다는 이론적 해석을 바탕으로 내부 모노폴과 슬리브 부분으로 구성되는 슬리브를 동축 선로로 동작하도록 하고 동축 선로의 특성 임피던스를 조절하여 슬리브의 임피던스 변환회로의 기능을 증대하였다. 슬리브 모노폴 안테나의 넓은 대역폭 확보를 위하여 두꺼운 모노폴을 사용하였고 슬리브의 임피던스 정합 회로로의 특성을 향상하기 위하여 동축 선로 역할을 하는 슬리브의 반경과 슬리브 내부를 구성하는 유전체의 유전율을 조절하여 슬리브 모노폴 안테나의 임피던스 대역폭을 최적화하였다. 두꺼운 모노폴을 사용하고 슬리브를 최적화하여 설계한 슬리브 모노폴 안테나는 반사 계수 10 dB 기준으로 0.80 GHz ~ 2.43 GHz 대역폭을 만족하는 3:1이 넘는 광대역 특성을 보였다. 제안한 슬리브 모노폴 안테나는 상용 이동 통신 주파수 대역에서 다기능 시스템에서 요구되는 다수의 안테나를 한 개의 안테나로 대체 가능할 것으로 기대한다.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.307-312
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• 2005

In this paper, the broadband FCMA(Folded Cross Monopole Antenna), which is the cross monopole antenna with the folded element, is presented. To investigate the broadband characteristics of FCMA the VSWR, the gain, and the radiation pattern are calculated in frequency between 1.75 GHz and 2.655 GHz. From the calculated result, it is shown that the presented folded cross monopole antenna has a excellent band characteristics than the existing cross monopole antenna. The presented antenna is conformed as a broadband antenna which can be used for the indoor antenna of PCS, WCDMA, Wibro, and satellite DMB band.

• Journal of information and communication convergence engineering
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• 제8권3호
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• pp.258-262
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• 2010

This paper represents design broadband impedance matching circuit for Coupler to improve power transfer efficiency in the broadband power line communication(BPLC) systems. The Butterworth gain function equalizer is used to design broadband matching circuit. A practical PLC Coupler impedance matching circuit is designed, and the characteristics for S11 and S21 of PLC Coupler are enhanced comparing with unmatched one. This is done by maximizing the power transfer gain from modem to the load.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2005년도 하계학술대회
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• pp.290-296
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• 2005

In this paper, we describe ubiquitous environments and the trend of convergence that is an evolution path of current telecommunication, and show the concept of broadband convergence network, service feature and evolution path. In order to converge wire and wireless communication, telecommunication and broadcasting, voice and data efficiently, broadband convergence network divides a network into service layer, control layer, transport layer, ubiquitous access and terminal layer. Broadband convergence network will be a network that can provide and control broadband multimedia services with QoS and securityof different and customized level. Then we depict characteristics and types of broadband multimedia service, and describe the characteristic of broadband convergence network. Finally, we show ubiquitous network based on the broadband convergence network to provide ubiquitous service which is a future telecommunication service. We also describe requirements of ubiquitous network such as an intelligent and context based platform, convergence terminals, ubiquitous computing devices, etc., and give various emerging technologies and those applications.

• 한국수산과학회지
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• 제48권2호
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• pp.221-232
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• 2015

Broadband echoes measured in live chub mackerel Scomber japonicus, goldeye rockfish Sebastes thompsoni, and fat greenling Hexagrammos otakii with different morphologies and internal characteristics were analyzed in time and frequency domains to understand the species-specific echo feature characteristics for classifying fish species. The mean echo image for each time-frequency representation dataset obtained as a function of orientation angle was extracted to mitigate the effect of fish orientation on acoustic scattering. The joint time-frequency content of the broadband echo signals was obtained using the smoothed pseudo-Wigner-Ville distribution (SPWVD). The SPWVDs were analyzed for each echo signature of the three fish species. The results show that the time-frequency analysis provided species-specific echo structure patterns and metrics of the broadband acoustic signals to facilitate fish species classification.

• 정보통신설비학회논문지
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• 제3권2호
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• pp.81-89
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• 2004

In this paper, we describe ubiquitous environments and the trend of convergence that is an evolution path of. current telecommunication, and show the concept of broadband convergence network, service feature and evolution path. In order to converge wire and wireless communication, telecommunication and broadcasting, voice and data efficiently, broadband convergence network divides a network into service layer, control layer, transport layer, ubiquitous access and terminal layer. Broadband convergence network will be a network that can provide and control broadband multimedia services with QoS and security of different and customized level. Then we depict characteristics and types of broadband multimedia service, and describe the characteristic of broadband convergence network. Finally, we show ubiquitous network based on the broadband convert- gence network to provide ubiquitous service which is a future telecommunication service. We also describe requirements of ubiquitous network such as an intelligent and context based platform, convergence terminals, ubi- quitous computing devices, etc.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2000년도 하계종합학술대회 논문집(1)
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• pp.173-176
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• 2000

In This paper, a novel broadband monopole antenna is investigated experimentally. Our broadband monopole antenna yields the largest bandwidth from 1.72 ∼ 2.2 GHz ( 24.2 ％ ) for VSWR<1.2 So, this antenna can be designed to extend enough the coverage of dual band(PCS＋IMT-2000). The measurements and computations are confirmed to operating of the our broadband antenna, whose electrical characteristics have an attractive feature as handset communication applications.

• Journal of electromagnetic engineering and science
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• 제16권3호
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• pp.191-193
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• 2016

This paper proposes a voltage-controlled oscillator (VCO) that has broadband turning and low-level of phase noise characteristics. Due to the micro-strip line resonant circuit with a low Q value, which is applied to the broadband tuning range, the depreciated phase noise performance is compensated by restraining the harmonics of the oscillating frequency. The VCO was designed according to the proposed structure as well as the conventional structure, and the superiority of the proposed structure was verified through its simulation, fabrication, and measurement.

• Journal of information and communication convergence engineering
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• 제7권2호
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• pp.113-118
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• 2009

This paper is about design broadband impedance matching circuit for Coupler to improve power transfer efficiency in the power line communication (PLC) system. The Tchebycheff gain function algorithm is represented to design broadband matching circuit. A practical PLC Coupler impedance matching circuit is designed, and the characteristics for S11 and S21 of PLC coupler are enhanced comparing with unmatched one. This is done by maximizing the power transfer gain from modem to the load.

• 한국전자파학회논문지
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• 제16권7호
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• pp.768-775
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• 2005

본 논문에서는 십자형 구조를 갖는 광대역 모노폴 안테나를 제시하고 모노폴 소자의 폭과 높이에 따른 복사 특성을 고찰하였다 제시된 모노폴 안테나는 십자형 구조의 복사 소자와 접지판과 소자 사이에 삽입한 임피던스 정합부에 의해 광대역 특성이 실현되었다. 제시된 안테나의 광대역 특성을 확인하기 위하여 주파수 $1.75\~2.655$ GHz에서 안테나를 설계$\cdot$제작하고 복사 특성을 측정하였다. 제시된 안테나는 수평면내 무지향성, 수직면내 지향성 특성을 가지며, VSWR은 사용 주파수 전대역에서 1.5 이하, 안테나 이득은 $2.5\~3.78$ dBi로 나타났다. 측정 결과로부터 제시된 안테나는 PCS, WCDMA, Wibro, 위성 DMB 밴드의 공용 실내 안테나로 사용될 수 있는 광대역 특성을 갖는 안테나로 확인되었다.