Vol. 98
Latest Volume
All Volumes
PIERL 123 [2025] PIERL 122 [2024] PIERL 121 [2024] PIERL 120 [2024] PIERL 119 [2024] PIERL 118 [2024] PIERL 117 [2024] PIERL 116 [2024] PIERL 115 [2024] PIERL 114 [2023] PIERL 113 [2023] PIERL 112 [2023] PIERL 111 [2023] PIERL 110 [2023] PIERL 109 [2023] PIERL 108 [2023] PIERL 107 [2022] PIERL 106 [2022] PIERL 105 [2022] PIERL 104 [2022] PIERL 103 [2022] PIERL 102 [2022] PIERL 101 [2021] PIERL 100 [2021] PIERL 99 [2021] PIERL 98 [2021] PIERL 97 [2021] PIERL 96 [2021] PIERL 95 [2021] PIERL 94 [2020] PIERL 93 [2020] PIERL 92 [2020] PIERL 91 [2020] PIERL 90 [2020] PIERL 89 [2020] PIERL 88 [2020] PIERL 87 [2019] PIERL 86 [2019] PIERL 85 [2019] PIERL 84 [2019] PIERL 83 [2019] PIERL 82 [2019] PIERL 81 [2019] PIERL 80 [2018] PIERL 79 [2018] PIERL 78 [2018] PIERL 77 [2018] PIERL 76 [2018] PIERL 75 [2018] PIERL 74 [2018] PIERL 73 [2018] PIERL 72 [2018] PIERL 71 [2017] PIERL 70 [2017] PIERL 69 [2017] PIERL 68 [2017] PIERL 67 [2017] PIERL 66 [2017] PIERL 65 [2017] PIERL 64 [2016] PIERL 63 [2016] PIERL 62 [2016] PIERL 61 [2016] PIERL 60 [2016] PIERL 59 [2016] PIERL 58 [2016] PIERL 57 [2015] PIERL 56 [2015] PIERL 55 [2015] PIERL 54 [2015] PIERL 53 [2015] PIERL 52 [2015] PIERL 51 [2015] PIERL 50 [2014] PIERL 49 [2014] PIERL 48 [2014] PIERL 47 [2014] PIERL 46 [2014] PIERL 45 [2014] PIERL 44 [2014] PIERL 43 [2013] PIERL 42 [2013] PIERL 41 [2013] PIERL 40 [2013] PIERL 39 [2013] PIERL 38 [2013] PIERL 37 [2013] PIERL 36 [2013] PIERL 35 [2012] PIERL 34 [2012] PIERL 33 [2012] PIERL 32 [2012] PIERL 31 [2012] PIERL 30 [2012] PIERL 29 [2012] PIERL 28 [2012] PIERL 27 [2011] PIERL 26 [2011] PIERL 25 [2011] PIERL 24 [2011] PIERL 23 [2011] PIERL 22 [2011] PIERL 21 [2011] PIERL 20 [2011] PIERL 19 [2010] PIERL 18 [2010] PIERL 17 [2010] PIERL 16 [2010] PIERL 15 [2010] PIERL 14 [2010] PIERL 13 [2010] PIERL 12 [2009] PIERL 11 [2009] PIERL 10 [2009] PIERL 9 [2009] PIERL 8 [2009] PIERL 7 [2009] PIERL 6 [2009] PIERL 5 [2008] PIERL 4 [2008] PIERL 3 [2008] PIERL 2 [2008] PIERL 1 [2008]
2021-06-28
Analysis and Design of Miniaturized Wideband Rat-Race Coupler with Improved Phase Performance
By
Progress In Electromagnetics Research Letters, Vol. 98, 129-137, 2021
Abstract
In the paper, a miniaturized wideband rat-race coupler with improved phase performance is designed and analyzed. Flat output ports phase differences are obtained by utilizing a component-loaded T-type transmission line (CLT-TL) with a stub-loaded short-circuited coupled line (SLS-CL). Let the CLT-TL and SLS-CL sections be equivalent to uniform 90° and 270° transmission lines, respectively. Design equations are derived, and an optimization is proceeded to obtain the circuit parameters. For validation, a prototype is designed, fabricated, and measured. Including the feeding lines, the circuit size is 0.31λg × 0.31λg. Under the criterion of return loss (RL) > 10 dB, the measured bandwidths for ports 1 and 3 excitations are both reach 48%. For amplitude imbalance (AP) < 0.5 dB, the overlap relative bandwidth is 46.88%. The measured bandwidths with 2° phase imbalance are 49.58% and 54.01% for ports 1 and 3 excitations, respectively.
Citation
Hongmei Liu, Yao Wang, Tielin Zhang, Shao-Jun Fang, and Zhongbao Wang, "Analysis and Design of Miniaturized Wideband Rat-Race Coupler with Improved Phase Performance," Progress In Electromagnetics Research Letters, Vol. 98, 129-137, 2021.
doi:10.2528/PIERL21050601
References

1. Pozar, D. M., Microwave Engineering, 3rd Ed., Wiley, New York, 2005.

2. Chang, W. S., C. H. Liang, and C. Y. Chang, "Slow-wave broadside-coupled microstrip lines and its application to the rat-race coupler," IEEE Microw. Wireless Compon. Lett., Vol. 25, No. 6, 361-363, Jun. 2015.
doi:10.1109/LMWC.2015.2421306

3. Chang, E. S. and C. Y. Chang, "A high slow-wave factor microstrip structure with simple design formulas and its application to microwave circuit design," IEEE Trans. Microw. Theory Techn., Vol. 60, No. 11, 3376-3383, Nov. 2012.
doi:10.1109/TMTT.2012.2216282

4. Wang, C. C., H. C. Chiu, and T. G. Ma, "A slow-wave multilayer synthesized coplanar waveguide and its applications to rat-race coupler and dual-mode filter," IEEE Trans. Microw. Theory Techn., Vol. 59, No. 7, 1719-1729, Jul. 2011.
doi:10.1109/TMTT.2011.2138713

5. Wang, Y. Q., K. X. Ma, N. N. Yan, and L. Y. Li, "A slow-wave rat-race coupler using substrate integrated suspended line technology," IEEE Trans. Compon. Packag. Manuf. Technol., Vol. 7, No. 4, 630-636, Apr. 2017.
doi:10.1109/TCPMT.2017.2661483

6. Tseng, C. H. and H. J. Chen, "Compact rat-race coupler using shunt-stub-based artificial transmission lines," IEEE Microw. Wireless Compon. Lett., Vol. 18, No. 11, 734-736, Nov. 2008.
doi:10.1109/LMWC.2008.2005225

7. Tseng, C. H. and C. L. Chang, "A rigorous design methodology for compact planar branch-line and rat-race couplers with asymmetrical T-structures," IEEE Trans. Microw. Theory Techn., Vol. 60, No. 7, 2085-2092, Jul. 2012.
doi:10.1109/TMTT.2012.2195019

8. Okabe, H., C. Caloz, and T. Itoh, "A compact enhanced-bandwidth hybrid ring using an artificial lumped-element left-handed transmission-line section," IEEE Trans. Microw. Theory Techn., Vol. 52, No. 3, 798-804, Mar. 2004.
doi:10.1109/TMTT.2004.823541

9. Eccleston, K. W. and S. H. M. Ong, "Compact planar microstripline branch-line and rat-race couplers," IEEE Trans. Microw. Theory Techn., Vol. 51, No. 10, 2119-2125, Oct. 2003.
doi:10.1109/TMTT.2003.817442

10. Gu, J. and X. Sun, "Miniaturization and harmonic suppression of branch-line and rat-race hybrid coupler using compensated spiral compact microstrip resonant cell," IEEE MTT-S Int. Microw. Symp. Dig., 1211-1214, 2005.

11. Lee, H. S., K. Choi, and H. Y. Hwang, "A harmonic and size reduced ring hybrid using coupled lines," IEEE Microw. Wireless Compon. Lett., Vol. 17, No. 4, 259-261, Apr. 2007.
doi:10.1109/LMWC.2007.892954

12. Ahn, H.-R. and M. M. Tentzeris, "Compact and wideband General Coupled-line Ring Hybrids (GCRHS) for arbitrary circumferences and arbitrary power-division ratios," IEEE Access, Vol. 7, 33414-33423, 2019.
doi:10.1109/ACCESS.2019.2902852

13. Ahn, H.-R. and M. M. Tentzeris, "A novel wideband compact microstrip coupled-line ring hybrid for arbitrarily high power-division ratios," IEEE Trans. Circuits Syst. II, Exp. Briefs, Vol. 64, No. 6, 630-634, Jun. 2017.
doi:10.1109/TCSII.2016.2598227

14. Ahn, H. R. and S. Nam, "Wideband microstrip coupled-line ring hybrids for high power-division ratios," IEEE Trans. Microw. Theory Techn., Vol. 61, No. 5, 1768-1780, May 2013.
doi:10.1109/TMTT.2013.2251654

15. Liang, C. H., W. S. Chang, and C. Y. Chang, "Enhanced coupling structures for tight couplers and wideband filters," IEEE Trans. Microw. Theory Techn., Vol. 59, No. 3, 574-583, Oct. 2011.
doi:10.1109/TMTT.2010.2094202

16. Yeung, L. K. and Y. E. Wang, "A novel 180 hybrid using broadside-coupled asymmetric coplanar striplines," IEEE Trans. Microw. Theory Techn., Vol. 55, No. 12, 2625-2630, Dec. 2007.
doi:10.1109/TMTT.2007.910067

17. Pan, Y. F., S. Y. Zheng, Y. M. Pan, Y. X. Li, and Y. L. Long, "A frequency tunable quadrature coupler with wide tuning range of center frequency and wide operating bandwidth," IEEE Trans. Circuits Syst. II, Exp. Briefs, Vol. 65, No. 7, 864-868, Jul. 2018.
doi:10.1109/TCSII.2017.2738662

18. Zysman, G. I. and A. K. Johnson, "Coupled transmission line networks in an inhomogeneous dielectric medium," ” IEEE Trans. Microw. Theory Techn., Vol. 17, No. 10, 753-759, Oct. 1969.
doi:10.1109/TMTT.1969.1127055

19. Muraguchi, M., T. Yukitake, and Y. Naito, "Optimum design of 3-dB branch-line couplers using microstrip lines," IEEE Trans. Microw. Theory Techn., Vol. 31, No. 8, 674-678, 1983.
doi:10.1109/TMTT.1983.1131568

20. Kennedy, J. and R. Eberhart, "Particle swarm optimization," ICNN95 — International Conference on Neural Networks, 2002.