• Title/Summary/Keyword: proximity coupled feeding

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Bandwidth Enhancement for a Proximity Coupled Microstrip patch Antenna with an Impedance Matching Network (임피던스 정합기를 이용한 근접 결합 급전 패치 안테나의 대역폭 확장)

  • Kwak, Eun-Hyuk;Kim, Boo-Gyoun
    • Journal of the Institute of Electronics and Information Engineers
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    • v.52 no.2
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    • pp.55-69
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    • 2015
  • Bandwidth enhancement technique for a proximity coupled patch antenna is investigated. The bandwidth and radiation characteristics of a proximity coupled patch antenna with an integrated impedance matching network printed on substrates with various dielectric constants and thicknesses are compared to those of a proximity coupled patch antenna without an impedance matching network. The bandwidth of a proximity coupled patch antenna with an integrated impedance matching network is greatly increased than that of a proximity coupled patch antenna without an impedance matching network without the degradation of radiation characteristics.

Design of Small CRPA Arrays with Circular Microstrip Loops for Electromagnetically Coupled Feed

  • Hur, Jun;Byun, Gangil;Choo, Hosung
    • Journal of electromagnetic engineering and science
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    • v.18 no.2
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    • pp.129-135
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    • 2018
  • This paper proposes a design of small controlled reception pattern antenna (CRPA) arrays using circular microstrip loops with frequency-insensitive characteristics. The proposed array consists of seven identical upper and lower circular loops that are electromagnetically coupled, which results in a frequency-insensitive behavior. To demonstrate the feasibility of the proposed feeding mechanism, the proposed array is fabricated, and its antenna characteristics are measured in a full-anechoic chamber. The operating principle of the proposed feeding mechanism is then interpreted using an equivalent circuit model, and the effectiveness of the circular loop shape is demonstrated by calculating near electromagnetic fields in proximity to the radiator. The results confirm that the proposed feeding mechanism is suitable to have frequency-insensitive behavior and induces strong electric and magnetic field strengths for higher radiation gain in extremely small antenna arrays.

Radiation Characteristics of a S / X Dual Broad Band Patch Antenna with Shared Aperture Structure (개구면 공유 구조를 가지는 S / X 이중 광대역 패치 안테나의 방사 특성)

  • Kwak, Eun-Hyuk;Lee, Yong-Seung;Kim, Boo-Gyoun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.8
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    • pp.718-729
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    • 2015
  • A S / X dual broad band patch antenna with shared aperture structure is fabricated. A $2{\times}2$ perforated patch is used for S-band operation and a $2{\times}2$ patch antenna array is integrated in the $2{\times}2$ perforation for X-band operation. The measurement results of a S / X dual broad band patch antenna with shared aperture structure show the broad band characteristics larger than 20 % in both bands.

RFID Tag Antenna Coupled by Shorted Microstrip Line for Metallic Surfaces

  • Choi, Won-Kyu;Kim, Jeong-Seok;Bae, Ji-Hoon;Choi, Gil-Young;Pyo, Cheol-Sig;Chae, Jong-Suk
    • ETRI Journal
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    • v.30 no.4
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    • pp.597-599
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    • 2008
  • This letter presents the design of a small and low-profile RFID tag antenna in the UHF band that can be mounted on metallic objects. The designed tag antenna, which uses a ceramic material as a substrate, consists of a radiating patch and a microstrip line with two shorting pins for a proximity-coupled feeding structure. Using this structure, impedance matching can be simply obtained between the antenna and tag chip without a matching network. The fractional impedance bandwidth for $S_{11}$ <3 dB and radiation efficiency are about 1.4% and 56% at 911 MHz, respectively. The read range is approximately from 5 m to 6 m when the tag antenna is mounted on a metallic surface.

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THE DEVELOPMENT OF CIRCULARLY POLARIZED SYNTHETIC APERTURE RADAR SENSOR MOUNTED ON UNMANNED AERIAL VEHICLE

  • Baharuddin, Merna;Akbar, Prilando Rizki;Sumantyo, Josaphat Tetuko Sri;Kuze, Hiroaki
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.441-444
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    • 2008
  • This paper describes the development of a circularly polarized microstrip antenna, as a part of the Circularly Polarized Synthetic Aperture Radar (CP-SAR) sensor which is currently under developed at the Microwave Remote Sensing Laboratory (MRSL) in Chiba University. CP-SAR is a new type of sensor developed for the purpose of remote sensing. With this sensor, lower-noise data/image will be obtained due to the absence of depolarization problems from propagation encounter in linearly polarized synthetic aperture radar. As well the data/images obtained will be investigated as the Axial Ratio Image (ARI), which is a new data that hopefully will reveal unique various backscattering characteristics. The sensor will be mounted on an Unmanned Aerial Vehicle (UAV) which will be aimed for fundamental research and applications. The microstrip antenna works in the frequency of 1.27 GHz (L-Band). The microstrip antenna utilized the proximity-coupled method of feeding. Initially, the optimization process of the single patch antenna design involving modifying the microstrip line feed to yield a high gain (above 5 dBi) and low return loss (below -10 dB). A minimum of 10 MHz bandwidth is targeted at below 3 dB of Axial Ratio for the circularly polarized antenna. A planar array from the single patch is formed next. Consideration for the array design is the beam radiation pattern in the azimuth and elevation plane which is specified based on the electrical and mechanical constraints of the UAV CP-SAR system. This research will contribute in the field of radar for remote sensing technology. The potential application is for landcover, disaster monitoring, snow cover, and oceanography mapping.

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