• Title/Summary/Keyword: vertical strip line

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Design of Electromagnetically Coupled Small Broadband Monopole Antenna with Vertical Ground Plane (수직 접지면을 가지는 전자기적 결합 급전 소형 광대역 모노폴 안테나의 설계)

  • Kim Myung-Bum;Jung Jong-Ho;Choo Hosung;Park Ikmo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.6 s.97
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    • pp.632-643
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    • 2005
  • This paper presents a folded stripline-fed small broadband disk-loaded monopole antenna with vertical ground plane. The bandwidth of the proposed antenna can be enhanced by electromagnetic coupling between the shorted rectangular disk and the probe with folded strip line. The measured impedance bandwidth of the proposed antenna is $37.6\%$ for $VSWR\leq2$ with the center frequency at 2.313 GHz and has the physical dimensions of only $11mm\times11mm\times11mm$ which corresponds to the electrical length of $0.085\lambda_0\times0.085\lambda_0\times0.085\lambda_0$. For improving the radiation pattern characteristics, rectangular slits are inserted in the vertical ground plane. Rectangular slits affect the currents distribution on the ground plane, so that the antenna radiation in the direction of the ground plane is reduced more than 3 dBi. Gain of the antenna is approximately 2.6 dBi within the bandwidth.

An Analysis of Similarity Measures for Area-based Multi-Image Matching (다중영상 영역기반 영상정합을 위한 유사성 측정방법 분석)

  • Noh, Myoung-Jong;Kim, Jung-Sub;Cho, Woo-Sug
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.30 no.2
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    • pp.143-152
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    • 2012
  • It is well-known that image matching is necessary for automatic generation of 3D data such as digital surface data from aerial images. Recently developed aerial digital cameras allow to capture multi-strip images with higher overlaps and less occluded areas than conventional analogue cameras and that much of researches on multi-image matching have been performed, particularly effective methods of measuring a similarity among multi-images using point features as well as linear features. This research aims to investigate similarity measuring methods such as SSD and SNCC incorporated into a area based multi-image matching method based on vertical line locus. In doing this, different similarity measuring entities such as grey value, grey value gradient, and average of grey value and its gradient are implemented and analyzed. Further, both dynamic and pre-fixed adaptive-window size are tested and analyzed in their behaviors in measuring similarity among multi-images. The aerial images used in the experiments were taken by a DMC aerial frame camera in three strips. The over-lap and side-lap are about 80% and 60%, respectively. In the experiment, it was found that the SNCC as similarity measuring method, the average of grey value and its gradient as similarity measuring entity, and dynamic adaptive-window size can be best fit to measuring area-based similarity in area based multi-image matching method based on vertical line locus.

A Study on 8 × 4 Dual-Polarized Array Antenna for X-Band Using LTCC-Based ME Dipole Antenna Structure (LTCC 기반 ME Dipole 안테나 구조를 활용한 X-Band 용 8 × 4 이중편파 배열안테나에 관한 연구)

  • Jung, Jae-Woong;Seo, Deokjin;Ryu, Jong-In
    • Journal of the Microelectronics and Packaging Society
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    • v.28 no.3
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    • pp.25-32
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    • 2021
  • In this paper, the Magneto-Electric(ME) dipole array antenna with dual-polarization in the X-Band is proposed and it is implemented and measured. The proposed array antenna is composed of 32 single ME dipole antenna and a Teflon PCB. 1 × 1 ME dipole antenna is implemented dual-polarization by radiating vertical polarization and horizontal polarization from two pairs of radiators. 2-port feeding structures are realized by lamination process using LTCC. And, each port independently feeds the radiator through a Γ-shaped feeding strip with isolation between ports. The Teflon PCB used in the antenna array has a 4-layer structure, and 2-port is fed through the top and bottom layers. The λg/4 transformer is applied to the transmission line of the Teflon PCB for impedance matching of the arrayed antenna and the Teflon PCB, and the optimal parameters are obtained through simulation. The measured maximum antenna gains of port 1 was 18.2 dBi, Cross-pol was 1.0 dBi. And the measured maximum antenna gains of port 1 was 18.1 dBi, Cross-pol was 3.2 dBi.