volume | PIER Journals

Abstract

This paper presents the first coupled-line coupler that provides independent power division ratios at dual bands. In contrast with previous dual-band coupled-line couplers, the power division ratios k²(f₂) and k²(f₂) at each band (f₁ and f₂) can be independently controlled in order to satisfy the requirements of various communication protocols at different bands. Moreover, it has a compact size due to the usage of coupled lines rather than transmission lines. Explicit design equations and design guide of the coupler are provided. In this letter, one prototype of the proposed coupler is simulated, fabricated, and measured. It provides power division ratios k²(f₁)=4 dB at f₁=1 GHz and k²(f₂)=8 dB at f₂=2.4 GHz. The measured result agrees well with the simulation.

1. Levy, R. and L. F. Lind, "Synthesis of symmetrical branch-guide directional couplers," IEEE Trans. Microw. Theory Techn., Vol. 16, No. 2, 80-89, Feb. 1968.
doi:10.1109/TMTT.1968.1126612 Google Scholar

2. Zhang, H. and K. J. Chen, "A stub tapped branch-line coupler for dual-band operations," IEEE Microw. Wireless Compon. Lett., Vol. 17, No. 2, 106-108, Feb. 2007.
doi:10.1109/LMWC.2006.890330 Google Scholar

3. Maktoomi, M. A., M. S. Hashmi, and F. M. Ghannouchi, "Systematic design technique for dualband branch-line coupler using T- and Pi-networks and their application in novel wideband-ratio crossover," IEEE Trans. Compon. Packag. Technol., Vol. 6, No. 5, 784-795, May 2016. Google Scholar

4. Chi, P. and K. Ho, "Design of dual-band coupler with arbitrary power division ratios and phase differences," IEEE Trans. Microw. Theory Techn., Vol. 62, No. 12, 2965-2974, Dec. 2014.
doi:10.1109/TMTT.2014.2364218 Google Scholar

5. Cheng, Y., L. Wang, J. Wu, and Y. Fan, "Directional coupler with good restraint outside the passband and its frequency agile application," Progress In Electromagnetics Research, Vol. 135, 759-771, 2013.
doi:10.2528/PIER12121009 Google Scholar

6. Gai, C., Y. Jiao, and Y. Zhao, "Compact dual-band branch-line coupler with dual transmission lines," IEEE Microw. Wireless Compon. Lett., Vol. 26, No. 5, 325-327, May 2016.
doi:10.1109/LMWC.2016.2549099 Google Scholar

7. Wu, Y., S. Y. Zheng, S. Leung, Y. Liu, and Q. Xue, "An analytical design method for a novel dual-band unequal coupler with four arbitrary trminated resistances," IEEE Trans. Ind. Electron., Vol. 61, No. 10, 5509-5516, Oct. 2014. Google Scholar

8. Wong, Y. S., S. Y. Zheng, and W. S. Chan, "Multifolded bandwidth banch line couplerwith filtering characteristic using coupled port feeding," Progress In Electromagnetics Research, Vol. 118, 17-35, 2011.
doi:10.2528/PIER11041401 Google Scholar

9. Chaudhary, G. and Y. Jeong, "Arbitrary power division ratio rat-race coupler with negative group delay characteristics," IEEE Microw. Wireless Compon. Lett., Vol. 26, No. 8, 565-567, Aug. 2016.
doi:10.1109/LMWC.2016.2585561 Google Scholar

10. Ahn, H. and M. M. Tentzeris, "Arbitrary power-division branch-line hybrids for high-performance, wideband, and selective harmonic suppressions from 2f0," IEEE Trans. Microw. Theory Techn., Vol. 67, No. 3, 978-987, Mar. 2019.
doi:10.1109/TMTT.2019.2892444 Google Scholar

11. Yeung, L. K., "A compact dual-band 90 coupler with coupled-line sections," IEEE Trans. Microw. Theory Techn., Vol. 59, No. 9, 2227-2232, Sep. 2011.
doi:10.1109/TMTT.2011.2160199 Google Scholar

12. Wang, X., W. Yin, and K. Wu, "A dual-band coupled-line coupler with an arbitrary coupling coefficient," IEEE Trans. Microw. Theory Techn., Vol. 60, No. 4, 945-951, Apr. 2012.
doi:10.1109/TMTT.2012.2185949 Google Scholar

13. Chang, C., K. Chin, and Y. Chiang, "Dual-band coupled-line couplers with wide separation between bands," IEEE Trans. Microw. Theory Techn., Vol. 65, No. 8, Aug. 2017.
doi:10.1109/TMTT.2017.2693153 Google Scholar

14. Corrales, E., A. Baldomero, and P. Paco, "A dual-band 180-degree hybrid coupler based on coupledline sections," IEEE Microw. Wireless Compon. Lett., Vol. 25, No. 4, 211-213, Apr. 2015.
doi:10.1109/LMWC.2015.2400922 Google Scholar

15. Chang, C., K. Chin, and Y. Zheng, "Design of dual-band −3 dB couplers with a wide range of dual-band frequency ratios," Electron. Lett., Vol. 52, No. 14, 1231-1233, Jul. 2016.
doi:10.1049/el.2016.1340 Google Scholar

16. Wu, Y., J. Shen, Y. Liu, S. Leung, and Q. Xue, "Miniaturized arbitrary phase-difference couplers for arbitrary coupling coefficients," IEEE Trans. Microw. Theory Techn., Vol. 61, No. 6, 2317-2324, Jun. 2013.
doi:10.1109/TMTT.2013.2259501 Google Scholar

17. Reshma, S. and M. K. Mandal, "Miniaturization of a 90◦ hybrid coupler with improved bandwidth performance," IEEE Microw. Wireless Compon. Lett., Vol. 26, No. 11, 891-893, Nov. 2016.
doi:10.1109/LMWC.2016.2614977 Google Scholar

Dr. Siyue Zhou

Dr. Xiaochuan Shen

Prof. Yongle Wu

Dr. Yuan'an Liu