Journal of IKEEE (전기전자학회논문지)

Institute of Korean Electrical and Electronics Engineers (한국전기전자학회)
권호 표지
DOI QR코드

DOI QR Code

A 3 dB Coupler for Double Sided Printed Circuit Boards

이층 기판용 3 dB 커플러

  • Lee, Dong-Ho (Dept. of Information and Communication Engineering, Hanbat National University)
  • Received : 2014.11.16
  • Accepted : 2014.12.08
  • Published : 2014.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

A 3 dB coupler has been designed and implemented using the most commonly used double-sided FR4 boards. The coupling and the bandwidth of the coupler are enhanced with the enlarged overlapped area of the coupler. Major design parameters are plotted as a design guide and the parameters are verified by simulation and measurement. The size of the manufactured coupler is $30{\times}14mm^2$. Its measured insertion loss and phase difference are 0.6 dB and $90.5^{\circ}$ at center frequency of 2.5 GHz, respectively. The operating frequency range is 1.72 GHz to 3.08 GHz for $3.6{\pm}0.5dB$ insertion loss. The coupler has the performance similar to that of conventional Lange coupler, and implementation of the coupler is easy and cheap with wide metal width and spacing and no additional wire bonding process.

가장 많이 쓰이는 FR4 이층 기판을 사용하여 3 dB 커플러를 설계하고 제작하였다. 커플러 일부의 겹치는 면적을 키워서 커플링을 증가시키고 대역폭을 증가시키는 구조를 제안하였다. 설계를 위한 주요 파라미터 값들을 여러 조건에 따라 도시하였고, 시뮬레이션과 측정을 통해 검증하였다. 제작된 커플러의 크기는 $30{\times}14mm^2$이고, 중심 주파수 2.5 GHz 에서 0.6 dB의 삽입 손실과 $90.5^{\circ}$의 위상차를 측정으로부터 얻었다. 측정된 삽입 손실 $3.6{\pm}0.5dB$에 대한 주파수 범위는 1.72 GHz에서 3.08 GHz이다. 제안한 커플러는 기존의 랭 커플러와 유사한 성능을 보였고, 와이어 본딩 공정이 필요 없어 추가 비용이 들지 않고 도선의 폭과 간격이 넓어서 제작이 용이하다.

Keywords

References

  1. R. K. Mongia, I. J. Bahl, P. Bhartia, J. Hong, RF and Microwave Coupled-Line Circuits, 2nd ed., Artech House, pp. 219-268, 2007.
  2. I. Wolff, Coplanar Microwave Integrated Circuits, John Wiley & Sons, Inc., pp. 109-120, 2006.
  3. S. S. Bedair, I. Wolff, "Fast and accurate analytic formulas for calculating the parameters of a general broadside-coupled coplanar waveguide for (M)MIC applications," IEEE Trans. Microwave Theory and Techniques, vol. 37, no. 5, pp. 843-850, May 1989. https://doi.org/10.1109/22.17450
  4. W. Hilberg, "From approximations to exact relations for characteristic impedances," IEEE Trans. Microwave Theory Techniques, vol. 13, no. 5, pp. 29-38, May 1965.
  5. J. Stewart, Calculus, 7th ed., Brooks/Cole, pp. 469-477, 2010.
  6. R. K. Mongia, I. J. Bahl, P. Bhartia, J. Hong, RF and Microwave Coupled-Line Circuits, 2nd ed., Artech House, pp. 167-195, 2007.
  7. A. M. Abbosh, M. E. Bialkowski, "Design of compact directional couplers for UWB applications," IEEE Trans. Microwave Theory and Techniques, vol. 55, no. 2, pp. 189-194, February 2007. https://doi.org/10.1109/TMTT.2006.889150
  8. J.-C. Chiu, C.-M. Lin, Y.-H. Wang, "A 3-dB quadrature coupler suitable for PCB circuit design," IEEE Trans. Microwave Theory and Techniques, vol. 54, no. 9, pp. 3521-3525, September 2006. https://doi.org/10.1109/TMTT.2006.879772