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

  • Received : 2015.11.16
  • Accepted : 2015.12.24
  • Published : 2016.03.31


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.


bandwidth enhancement;double dipole quasi-Yagi antenna;modified microstrip-to-coplanar strip line balun;mobile communication


  1. R. Waterhouse, Printed Antennas for Wireless Communications. Chichester, U.K.: Wiley, 2007.
  2. N. Kaneda, W. R. Deal, Y. Qian, R. Waterhouse, and T. Itoh, "A broad-band planar quasi-Yagi antenna," IEEE Trans. Antennas Propagat., vol. 50, no. 8, pp. 1158-1160, Aug. 2002.
  3. J.-I. Lee and J. Yeo, "Design of a simple three-element quasi-Yagi antenna with a broad impedance bandwidth up to 2.4 : 1," J. Electromagn. Waves Appl., vol. 27, no. 17, pp. 2247-2262, 2013.
  4. F. Tefiku and C. A. Grimes, "Design of broad-band and dual-band antennas comprised of series-fed printed-strip dipole pairs," IEEE Trans. Antennas Propagat., vol. 48, no. 6, pp. 895-900, Jun. 2000.
  5. J. Yeo and J.-I. Lee, "Broadband series-fed two dipole array antenna with an integrated balun for mobile communication applications," Microw. Opt. Technol. Lett., vol. 54, no. 9, pp. 2166-2168, Sep. 2012.
  6. J. M. Steyn, J. W. Odendaal, J. and Joubert, "Double dipole antenna for dual-band wireless local area networks applications," Microw. Opt. Technol. Lett., vol. 51, no. 9, pp. 2034-2038, Sep. 2009.