• Title/Summary/Keyword: 다이폴 안테나

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Design of Cavity-Backed Microstrip Dipole Array Antennas with Enhanced Front-to-Back Ratio (전후방비가 개선된 Cavity-Backed 마이크로스트립 다이폴 배열 안테나 설계)

  • You, Dong-Gyun;Jeon, Jung-Ik;Lee, Hyoung-Ki;Choi, Hak-Keun
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.20 no.1
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    • pp.37-44
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    • 2009
  • In this paper, a TRS band(Trunked Radio System: $806{\sim}866\;MHz$) array antenna has a good front-to-back ratio characteristics for the mobile communication base station is proposed. The proposed array antenna is composed of the $5{\times}3$ radiated elements which are the microstrip dipole antennas with the cavity-backed reflector. For the validity of the proposed antenna, the $5{\times}3$ array antenna is designed, fabricated, and its radiation characteristics are measured. As a result of measurements, the antenna gain is over 13.3 dBi and the front-to-back ratio is over 40 dB at the useable frequency band. We confirm that the designed antenna can be used as the mobile communication base station antenna with the excellent back lobe characteristics.

Design of S-band Turnstile Antenna Using the Parasitic Monopole (기생 모노폴을 이용한 S-band Turnstile 안테나 설계)

  • Lee, Jung-Su;Oh, Chi-Wook;Seo, Gyu-Jae;Oh, Seung-Han
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.11 s.114
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    • pp.1082-1088
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    • 2006
  • A turnstile antenna using the parasitic monopole has been developed for STSAT-2 TT&C application. The antenna consists of two radiating elements; a bow-tie dipole and a parasitic monopole. The bow-tie dipole is main radiating element, used a bow-tie structure for bandwidth improvement and size reduction. The parasitic monopole improved beamwidth and axial ratio. The input impedance of the antenna is about 50 ohm without a matching circuit. The proposed antenna has beamwidth of $>140^{\circ}$, axial ratio of < 3 dB and VSWR of < 1.5 in the band of $2.075{\sim}2.282GHz$.

Analysis and Measurement of RCS for UHF Band RFID Tag Antennas (UHF 대역 RFID 태그 안테나의 RCS(Radar Cross Sections) 분석 및 측정)

  • Moon, Hyo-Sang;Kim, Nam-Hoon;Lee, Jong-Wook;Lee, Bom-Son
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.1 s.116
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    • pp.31-36
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    • 2007
  • In the RFID system, one of the important criteria of tag antenna performance is the detection distance. The most important factor determining the detection distance of the tag antenna is the Radar Cross Sections(RCS). In this paper, we propose a method to simply measure the RCS of the RFID tag antenna using two reader antennas(Tx and Rx) and a network analyzer. We estimate RCS' from the RCS equation based on the measured $S_{21}$ using the network analyzer. We compare the measured $S_{21}$ values with the calculated $S_{21}$ values and the simulated $S_{21}$ values using EM simulator. The used tag antennas are two kinds of dipole-type, metal-type, and an inductively-coupled type ones. In case of the dipole type, the measured, simulated and calculated values of the RCS are almost the same. In case of other types, we obtain the measured RCS values with a difference of about 3 dB.

Design and Performance Evaluation of the Resistive V-Dipole for Surface and Subsurface Probing (지표 및 지하 탐사를 위한 저항성 V 다이폴의 디자인과 성능에 대한 연구)

  • Kim, Kang-Wook;Scott, Waymond R. Jr.
    • 한국지구물리탐사학회:학술대회논문집
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    • 2006.06a
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    • pp.281-284
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    • 2006
  • The resistive V dipole (RVD) is a V antenna with both arms loaded with the continuous Wu-King resistive profile. The RVD has many advantages for surface and subsurface probing, such as the ability to radiate a short pulse in a desired direction. The radiated pulse is simply related to the input pulse, e.g., derivative. In addition, it mostly eliminates the multiple reflections between the surface of the ground and the antenna because of its low radar cross section. The drawbacks of the RVD include the high input impedance and the difficulty in implementation. This paper presents ways to improve the accuracy and easiness of the implementation and to improve the low-frequency performance while maintaining the characteristics of the V antenna that are good for probing applications. The implemented antenna is used to form a bistatic radar to scan targets underground, and the result is imaged.

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Bandwidth Enhancement of Double-Dipole Quasi-Yagi Antenna Using Modified Microstrip-to-Coplanar Strip line Balun (변형된 마이크로스트립-동일면 스트립 선로 밸런을 이용한 이중 다이폴 준-야기 안테나의 대역폭 향상)

  • Yeo, Junho;Lee, Jong-Ig;Baek, Woon-Seok
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.3
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    • pp.457-463
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    • 2016
  • In this paper, a method of enhancing the bandwidth of a double-dipole quasi-Yagi antenna (DDQYA) using a modified integrated balun is presented. The modified integrated balun consists of a microstrip (MS) line inserted along the center of a coplanar strip (CPS) line and the end of the MS line is connected to the CPS line through a shorting pin at the feed point. The geometry of the modified integrated balun is adjusted to improve the bandwidth of the DDQYA. In addition, the performance of the proposed balun in a back-to-back configuration is compared with a conventional balun. The proposed antenna with the optimized modified integrated balun is fabricated on an FR4 substrate, and the experiment results show that the antenna has a frequency band of 1.56-3.04 GHz(64.4%) for a VSWR < 2, which shows enhanced bandwidth compared to the DDQYA with the conventional balun.