• 전기학회논문지P
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• 제61권3호
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• pp.149-152
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• 2012

In this paper, a wideband monopole antenna with ring loop by modified ground plane is presented. The proposed antenna consist of monopole antenna, ring loop by ground plane. This antenna is fed CPW-fed and wide slot antenna of a novel structure for broadband characteristics is proposed. To enhance the impedance bandwidth of the wide slot antenna, we proposed the wide slot structure with CPW-fed which is combined with four ${\lambda}/2$ rectangular radiation modified monopole and inductively coupled. The measured impedance bandwidth is about 2.5 GHz(3.65~6.15 GHz) then less -10 dB.

• 전기학회논문지P
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• 제60권2호
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• pp.53-55
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• 2011

The printed wide band monopole antenna having characteristics of dipole by modified coplanar wave guide(CPW) ground plane is presented. We are called a slot-arm printed monopole antenna and investigated the effect of the surface currents of the radiator on ground plane. The proposed antenna is treated as two asymmetric dipoles with the included angle of $90^{\circ}$ degrees which lie along Z-direction symmetrically. It is observed that the effect of the surface currents on the radiation patterns is similar to that of the corresponding dipole. The length and width of the ground plane correspond the radius and length of the dipole respectively. This approach is also valid to general printed monopole antennas. The simulation impedance bandwidth of the proposed antenna the range of 2.4 to 4.6 [GHz] for a voltage stand wave ratio (VSWR)${\leq}$2 and got pick gain of 6 [dBi]. So the proposed antenna is satisfied the requirement of the industry science medical (ISM) band operation.

• ETRI Journal
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• 제31권5호
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• pp.616-618
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• 2009

In this letter, a novel hybrid planar inverted-F antenna (PIFA) with a T-shaped slot on the ground plane is proposed. The loop structure formed by the feed line and shorting pin can be operated as a series and shunt inductance for the PIFA and the T-shaped slot antenna, respectively. The PIFA operates at a frequency of 1.75 GHz, while the T-shaped slot on the ground plane operates at 2.4 GHz by the same voltage feeding source. The height of the PIFA is 6.5 mm, and the size of an upper patch is designed to be 30 mm${\times}$16 mm. The measured relative impedance bandwidth of the PIFA and the T-shaped slot are about 12% and 21%, respectively. In addition, good antenna performance was achieved.

• 한국정보통신학회논문지
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• 제17권10호
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• pp.2265-2272
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• 2013

본 논문에서는 WLAN 시스템에 적용 가능한 이중 공진을 갖는 변형된 원형 링 안테나를 설계 및 제작 하였다. 제안된 안테나는 평면형 모노폴 설계를 기본으로 원형 링 모양의 구조와 변형된 급전선로, 그리고 접지면의 사각 슬롯으로 구성함으로서 이중대역 특성을 갖도록 설계하였다. 최적화된 파라메타를 얻기 위해 상용 툴(HFSS)을 사용하여 시뮬레이션 하였으며 안테나 성능에 민감하게 작용하는 파라메타를 찾아내서 최적화된 수치를 얻었다. 얻어진 최적화된 수치를 사용하여 제안된 안테나를 제작하였으며 WLAN 대역에서 반사손실, 이득, 방사패턴의 특성을 측정하였다.

• 한국전자파학회논문지
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• 제22권3호
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• pp.275-281
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• 2011

본 논문에서는 UWB 통신을 위한 변형된 접지 면을 갖는 소형 평판형 모노폴 안테나를 제안하였다. 제안된 안테나는 UWB 통신에 적합한 초광대역 특성(3.1~10.6 GHz)을 만족하면서, 5 GHz WLAN 대역(5.15~5.35 GHz, 5.470~5.825 GHz)에 주파수 대역 저지 특성을 갖는다. 제안된 안테나는 접지 면에 두 개의 슬릿을 통해 임피던스 정합 특성을 향상시켰으며, 슬릿의 중앙으로부터 저지 대역의��${\lambda}$/4 길이를 갖는 두 개의 개방 스터브를 형성하여 주파수 대역 저지 특성을 유도하였다. 제작된 안테나는 저지 대역인 5.08~5.83 GHz를 제외하고, 2.88~10.83 GHz 대역에서 VSWR${\leq}$2를 만족한다.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.893-895
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• 2013

본 논문에서는 접지면에 역 T형 노치를 넣은 평면형 폴디드 모노폴 안테나를 제안하였다. 제안된 안테나에서는 대역폭을 늘리기 위하여 내부 패치와 외부 패치의 폭들을 점차 넓히는 방향으로 변화를 주었고, 그라운드에 가로와 세로 slit의 길이가 비슷하고 폭은 약 2배 정도 차이가 있는 노치를 넣어 설계 및 모의실험을 하였다.

• 전기학회논문지
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• 제65권9호
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• pp.1564-1570
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• 2016

This study proposes a newly modified form of existing ground electrodes in order to secure trust of grounding system for large current caused by a stroke of lightning. Proposed planar earth structure has a several needle electrodes around a circular rod and 4 plane electrodes in all directions. The plane electrodes are fused with the insulator on the linear rod, so that they're electrically isolated. The concept is to increase the discharge amount of earth structure using multiple discharge paths like needle and plane electrodes. To check the discharge efficiency of the suggested scheme, the discharge currents are compared with typically used two kinds of ground rods. To ensure accuracy in the measurement of the discharge current, the same material was used for the comparison model. Also, the ground resistance are simulated by CDEGS commercial software and the results are compared with measured data. Based on this kind of experimental study, the suggested ground rod can be used when designing a ground system or when constructing a ground system at the site.

• 한국산학기술학회논문지
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• 제8권4호
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• pp.815-820
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• 2007

본 논문에서는 휴대용 무선통신기기에 장착해서 사용 가능한 소형 내장형 이중대역(RFID, PCS) 안테나가 소개되었다. 제안된 안테나는 기본적인 PIFA(Planar Inverted-F Antenna) 구조이며 기존 안테나 방사체 아래쪽에 변형된 접지구조를 추가하였다. 이 변형된 접지 구조는 안테나에 의해 유기되는 전류를 분산시키고 안테나 주 방사부와 결합성분을 유도하여 안테나를 소형화시킨다. 시뮬레이션 결과에 따라 안테나가 실제 제작되고 측정되었으며 변형된 접지로 인해 공진 주파수가 낮은 주파수 대역으로 150MHz 정도 이동하는 것을 볼 수 있었다. 그리고 제안된 안테나의 표면전류가 분산되는 특징이 관찰되어 전자파흡수율(SAR)과 보청기호환성(HAC)을 개선하는데 사용될 수 있다.

• ETRI Journal
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• 제17권4호
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• pp.13-24
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• 1996

We determine the reduced mass of heavy-hole exciton and the heavy-hole in-plane mass for a series of (In, Ga)As/GaAs strained layer quantum wells using the magnetolu-minescence measurements of the exciton ground state and the modified perturbation approach. In the theoretical calculation of the magnetoexciton ground state, the exciton reduced mass is considered as an adjustable parameter, and two variation parameters are used in the unperturbed wave function which is expressed in terms of subband wave functions in the growth axis and the product of two-dimensional hydrogen and oscillator like wave functions for the in-plane component. We take into account the energy dependence of transverse and in-plane electron masses in the twoband effective mass approximation. The electron effective mass decreases as either quantum-well width or indium composition increases, and so does the heavy-hole in-plane mass down to the value at the decoupling limit ($m_{hh,\;{\rho}}=0.11m_0$).

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 1998년도 봄 학술발표회 논문집
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• pp.357-364
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• 1998

In this paper, ground vibration analysis methods for train transit on bridges are studied. Train loads acting on the piers are evaluated considering the interactions between the trains and the bridge. The 2D in-plane wave propagation method and the axisymmetric wave propagation method are used in the ground vibration analysis, and then the results of the ground vibration are compared. A modified axisymmetric method is presented, which can consider the effect of the train loadings on a series of piers as the train moves.