• Title/Summary/Keyword: Aperture-coupled

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An Aperture-coupled Microstrip Shaped-beam Array Antenna for the PCS Basestation (개구 결합 구조를 갖는 PCS 기지국용 마이크로스트립 정형 빔 배열 안테나)

  • Yeo, Un Sik;Kim, Gwang Jo;Gang, Seung Taek;Kim, Hyeong Dong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.8 no.6
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    • pp.636-636
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    • 1997
  • This paper presents the design and fabrication of a shaped-beam array antenna which will be used for a PCS basestation using structure that is coupled to a microstrip line by an aperture on the intervening ground plane. The shaped-beam pattern is obtained by an antenna synthesis method. An array antenna considering the mutual coupling between array elements(patches) and a feeding network are designed by CAD tools. The feeding network is designed by using the Wilkinson power divider to obtain the optimized shaped-beam. The designed results are compared with the measured data.

Design and Fabrication of Aperture-Coupled Microstrip Cylindrical Dielectric Resonant Antenna for Wireless LAN (무선 LAN용 개구결합 마이크로스트립 원통형 유전체 공진 안테나 설계 및 제작)

  • 이권익;김흥수
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.12 no.3
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    • pp.425-431
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    • 2001
  • In this paper, on aperture-coupled microstrip cylindrical dielectric resonant antenna(DRA) consisting of dielectric material with permittivity ${\epsilon}_{r}$ = 36 is designed and fabricated fir wireless LAN. First of all, the feedline length, width, slot length and width of the feeding element were calculated using the theory of microstrip transmission line. Radiation element is designed using the theory of cylindrical dielectric cavity, Resonant frequency of the fabricated cylindrical DRA is 2.449 GHz and VSWR, return loss and bandwidth is 1.009, -47 dB and 70 MHz, respectively. Front-to-back radiation ratio is about 12 dB and 3 dB beamwidth of E-plane and H-plane is 110$^{\circ}$ and 90$^{\circ}$ , respectively.

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The Design and Characteristics of Aperture Coupled Wideband Microstrip Antenna with the T-shaped Feedline (T-모양 급전선을 갖는 개구 결합 광대역 마이크로스트립 안테나의 설계 및 그 특성)

  • Jang, Yong-Ung
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.37 no.12
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    • pp.32-37
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    • 2000
  • We proposed to a new method of the aperture coupled microstrip antenna with T-shaped feeding slot. We analyzed method of enhancing the bandwidth of the antenna using FDTD. And the antenna parameters are optimized to get maximum bandwidth. We also calculated the progress process of waves and the distribution of electric field in the time domain. We also calculated return loss, VSWR, input impedance, radiation pattern in the frequency domain by Fourier transforming the time domain results, respectively. It was found that the bandwidth of this antenna changes length and width of the patch, length and width of the slot, length of T-shaped feedline, position of the offset. Measured % bandwidth was 49.2 % in the center frequency 2.5 GHz. These results were in relatively food accordance with calculated values.

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A Study of Beam Tilted Antenna by Aperture Coupled Microstrip Array (개구 급전 마이크로스트립 배열에 의한 빔 틸팅 안테나에 관한 연구)

  • 고진현;하재권;박덕규
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 1999.11a
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    • pp.151-155
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    • 1999
  • We proposed the beam tilted antenna by aperture coupled microstrip array, found out the values of design parameters by using Ensemble 5.1 of Ansoft Co., and analysed the performance of fabricated antenna. In order to point to the fixed satellite on the nothern hemisphere, 3 dB beamwidth of this antenna is 25$^{\circ}C$ to 65$^{\circ}C$. Operation bandwidth is 2.51GHz to 2.59GHz. The structure of this antenna is composed by 3 types of squared patches; reflector, driver, and director. The maximum antenna gain is 6.2dB at 2.56GHz and elevation angle of 42$^{\circ}C$. Front-to-Back ratio is more than 13dB at the same condition.

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A Study on the Synthetic Aperture Radar Processor using AOD/CCD (AOD/CCD를 이용한 합성개구면 레이다 처리기에 관한 연구)

  • 박기환;이영훈;이영국;은재정;박한규
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.19 no.10
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    • pp.1957-1964
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    • 1994
  • In this thesis, a Synthetic Aperture Rarar Processor that is possible real-time handling is implemented using CW(Continuose Wave) laser as a light source, CCD(charge Coupled Device) as a time integrator, and AOD(Acousto-Optic Device) as the space integrator. One of the advantages of the proposed system is that it does not require driving circuits of the light source. To implement the system, the linear frequency modulation(chirp) technique has been used for radar signal. The received data for the unit target was processed using 7.80 board and accompanying electronic circuits. In order to reduce the smear effect of the focused chirp signal which occurs Bragg diffrection angle of the AOD has been utilized to make sharp pulses of the laser source, and the pulse made synchronized with the chirp signal. Experiment and analysis results of the data and images detected from CCD of the proposed SAR system demonstrated that detection effect is degrated as the unit target distance increases, and the resolving power is improved as the bandwidth of the chirp signal increases. Also, as the pulse width of the light source decreases, the smear effect has been reduced. The experimental results assured that the proposed system in this papre can be used as a real time SAR processor.

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Hydraulic-Mechanical Modeling on Fracture Transmissivity Evolution Around a Borehole (시추공 주변 단열 투수도 진화에 대한 수리-역학 연동 모델링 평가)

  • Choi, Chae-Soon;Park, Kyung-Woo;Park, Byeong-Hak;Ko, Nak-Youl;Ji, Sung-Hoon
    • The Journal of Engineering Geology
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    • v.31 no.1
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    • pp.55-66
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    • 2021
  • Hydraulic-mechanical (H-M) coupled numerical modeling was used to evaluate the evolution of hydrogeological properties in response to the installation and expansion of a borehole. A domain with a discrete fracture network was adopted for discontinuum modeling to simulate changes in fracture apertures. Comparison with real hydraulic test data shows that the effects of principal stress direction and expansion of borehole diameter were reasonably simulated by H-M coupled numerical modeling. The modeling confirmed that aperture changes depended on the principal stress direction, with an increase in aperture size due to vertical displacement being the dominant effect. A concentration of shear dilation around the borehole had an additional, subsidiary, effect on the hydrogeological evolution. These results show that the permeability of fractured rock can be increased by changing the hydraulic properties of a fracture through stress redistribution caused by the installation and expansion of a borehole.

Microfabrication of submicron-size hole for potential held emission and near field optical sensor applications (전계방출 및 근접 광센서 응용을 위한 서브 마이크론 aperture의 제작)

  • Lee, J.W.;Park, S.S.;Kim, J.W.;M.Y. Jung;Kim, D.W.
    • Journal of the Korean Vacuum Society
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    • v.9 no.2
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    • pp.99-101
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    • 2000
  • The fabrication of the submicron size hole has been interesting due to the potential application of the near field optical sensor or liquid metal ion source. The 2 micron size dot array was photolithographically patterned. After formation of the V-groove shape by anisotropic KOH etching, dry oxidation at $1000^{\circ}C$ for 600 minutes was followed. In this procedure, the orientation dependent oxide growth was performed to have an etch-mask for dry etching. The reactive ion etching by the inductively coupled plasma (ICP) system was performed in order to etch ~90 nm $SiO_2$ layer at the bottom of the V-groove and to etch the Si at the bottom. The negative ion energy would enhance the anisotropic etching by the $Cl_2$ gas. After etching, the remaining thickness of the oxide on the Si(111) surface was measured to be ~130 nm by scanning electron microscopy. The etched Si aperture can be used for NSOM sensor.

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Compact Multi-harmonic Suppression LTCC Bandpass Filter Using Parallel Short-Ended Coupled-Line Structure

  • Wang, Xu-Guang;Yun, Young;Kang, In-Ho
    • ETRI Journal
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    • v.31 no.3
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    • pp.254-262
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    • 2009
  • This paper presents a novel simple filter design method based on a parallel short-ended coupled-line structure with capacitive loading for size reduction and ultra-broad rejection of spurious passbands. In addition, the introduction of a cross-coupling capacitor into the miniaturized coupled-line can create a transmission zero at the second harmonic frequency for better frequency selectivity and attenuation level. The aperture compensation technique is also applied to achieve a strong coupling in the coupled-line section. The influence of using the connecting transmission line to cascade two identical one-stage filters is studied for the first time. Specifically, such a two-stage bandpass filter operating at 2.3 GHz with a fractional bandwidth of 10% was designed and realized with low-temperature co-fired ceramic technology for application in base stations that need high power handling capability. It achieved attenuation in excess of -40 dB up to $4f_0$ and low insertion loss of -1.2 dB with the size of 10 mm ${\times}$ 7 mm ${\times}$ 2.2 mm. The measured and simulated results showed good agreement.

Dual-Band Microstrip Antenna for ISM Band using Aperture Coupled Cross Patch (개구 결합된 십자형 패치를 이용한 ISM 대역용 이중대역 마이크로스트립 안테나)

  • 박기동;정문숙;임영석
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.14 no.5
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    • pp.479-488
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    • 2003
  • Dual-band microstrip antenna is designed for industrial-scientific-medical(ISM) band of 2.4 GHz and 5.8 GHz using finite-difference time-domain method(FDTD). Cross patch 130 by aperture in the ground plane of microstrip line is proposed as radiation element of antenna which is 2 rectangular patch is overlapped. To design antenna, change of input impedance is examined by length change of aperture and stub. And center frequency and - 10 dB bandwidth are investigated by change of length and width in radiation element. Measured result about reflection loss confirm that agree well with simulation results of FDTD and IE3D. And 3 dB beam width, front to back ratio and maximum gain is presented by measuring radiation pattern of antenna in frequency 2.43 GHz and 5.79 GHz.

Analysis of Electromagnetic Pulse Coupling Via a Slot Aperture into Parallel-Plate waveguide (슬롯 개구를 통한 평행평판 도파관 내부로의 전자파 펄스 결합문제 해석)

  • 이영순;박의준
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.11 no.7
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    • pp.1204-1210
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    • 2000
  • An analysis method for obtaining transient response of electromagnetic pulse(EMP) coupled via a slot aperture into a parallel-plate waveguide, is considered. The mixed-potential integral equation(MPIE), in which the vector and scalar potential Green's functions for the unknown equivalent magnetic surface current of the aperture in parallel-plate region are expressed in closed forms derived by use of the improved complex image method, is formulated. When the method of moments(MoM) is used to solve the MPIE, the matrix-fill time is significantly reduced because of closed-form Green's functions. In order to check the validity of the present method, the numerical results obtained by the present method are compared with those obtained by the previous method. Fairly good agreements between them are observed.

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