volume | PIER Journals

Abstract

In this paper, new miniaturized hybrid branch line couplers loaded by square-split ring resonators are proposed. This loading technique increases the electrical length of transmission lines by patterning the ground plane under the conductor trace in microstrip lines with the complementary, dual-behavior, configuration of square-split ring resonators. Each branch is loaded by one resonator in the first coupler and by two resonators in the second coupler. Hence, compact sizes of 9.29 mm × 9.57 mm, and 8.88 mm × 9.11 mm, or equivalently 0.2λg × 0.2λg and 0.19λg × 0.19λg, respectively, are obtained at the operation frequency, 2.4 GHz. This corresponds to 66.14% and 60.18% of a conventional structure's area, respectively. Moreover, the new designs can suppress higher harmonic components due to the bandstop response of the square-split resonators at their resonant frequency while maintaining similar measured performance compared to the conventional branch-line hybrid coupler. Measured and simulated responses are in very good agreement which validates the proposed structures and technique. This technique can also be applied to minimize the size of other microwave circuits.

1. Pendry, J. B., A. J. Holden, D. J. Ribbins, and W. J. Stewart, "Magnetism from conductors and enhanced nonlinear phenomena," IEEE Trans. Microwave Theory Tech., Vol. 47, 2075-2084, Nov. 1999.
doi:10.1109/22.798002 Google Scholar

2. Baena, J. D., J. Bonache, F. Martin, R. Marques, F. Falcone, T. Lopetegi, M. A. G. Laso, J. Garcia, I. Gil, and M. Sorolla, "Equivalent-circuit models for split-ring resonators and complementary split-ring resonators coupled to planar transmission lines," IEEE Trans. Microwave Theory Tech., Vol. 53, No. 4, 1451-1461, Apr. 2005.
doi:10.1109/TMTT.2005.845211 Google Scholar

3. Caloz, C., H. Okabe, H. Iwai, and T. Itoh, "Transmission line approach of left-handed metamaterials," USNC/URSI National Science Meeting, San Antonio, TX, Jun. 16-21, 2002. Google Scholar

4. Saha, C., J. Y. Siddiqui, and Y. M. M. Antar, "Square split ring resonator backed coplanar waveguide for filter applications," 2011 XXXth URSI General Assembly and Scientific Symposium, 1-4, Aug. 13-20, 2011. Google Scholar

5. Falcone, F., T. Lopetegi, J. D. Baena, R. Marques, F. Martin, and M. Sorolla, "Effective negative-ε stopband microstrip lines based on complementary split ring resonators," IEEE Microw. Wireless Compon. Lett., Vol. 14, No. 6, 280-282, Jun. 2004.
doi:10.1109/LMWC.2004.828029 Google Scholar

6. Pasakawee, S. and Z. Hu, "Left-handed microstrip delay line implemented by complementary split ring resonators (CSRRs)," Asia Pacific Microwave Conference 2009, 599-601, 2009.
doi:10.1109/APMC.2009.5384155 Google Scholar

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

8. Shum, K. M., Q. Xue, and C. H. Chan, "A novel microstrip ring hybrid incorporating a PBG cell," IEEE Microw. Wireless Compon. Lett., Vol. 11, No. 6, 258-260, Jun. 2001.
doi:10.1109/7260.928931 Google Scholar

9. Mondal, P. and A. Chakrabarty, "Design of miniaturised branch-line and rat-race hybrid couplers with harmonics suppression," IET Microwaves, Antennas & Propagation, Vol. 3, No. 1, 109-116, Feb. 2009.
doi:10.1049/iet-map:20070202 Google Scholar

10. Bekasiewicz, A., P. Kurgan, and M. Kitlinski, "New approach to a fast and accurate design of microwave circuits with complex topologies," topologies," IET Microwaves, Antennas & Propagation, Vol. 6, No. 14, 1616-1622, Nov. 2012.
doi:10.1049/iet-map.2012.0434 Google Scholar

11. Jung, S.-C., R. Negra, and F. M. Ghannouchi, "A design methodology for miniaturized 3-dB branch-line hybrid couplers using distributed capacitors printed in the inner area," IEEE Trans. Microwave Theory Tech., Vol. 56, No. 2, 2950-2953, 2008.
doi:10.1109/TMTT.2008.2007323 Google Scholar

12. Marques, R., F. Mesa, J. Martel, and F. Medina, "Comparative analysis of edge- and broadside-coupled split ring resonators for metamaterial design --- Theory and experiment," IEEE Trans. Antennas Propag., Vol. 51, No. 10, 2572-2581, Oct. 2003.
doi:10.1109/TAP.2003.817562 Google Scholar

13. Zhang, J. and X.-W. Sun, "Harmonic suppression of branch-line and rat-race coupler using complementary spilt ring resonators (CSRR) cell," Progress In Electromagnetics Research Letters, Vol. 2, 73-79, 2008.
doi:10.2528/PIERL07122702 Google Scholar

14. Zeland Software, Inc. "IE3D simulator,", Fremont, CA, 2007. Google Scholar

15. Simons, R. N., Coplanar Waveguide Circuits, Components, and Systems, John Wiley & Sons, 2001.
doi:10.1002/0471224758

16. Martin, F., F. Falcone, J. Bonache, R. Marques, and M. Sorolla, "A new split ring resonator based left handed coplanar waveguide," Appl. Phys. Lett., Vol. 83, 4652-4654, 2003.
doi:10.1063/1.1631392 Google Scholar

Dr. Lamia Al-Khateeb