1. Veselago, V. G., "The electrodynamics of substances with simultaneously negative values of ε and μ," Sov. Phys. Usp., Vol. 10, 509-514, 1968.
doi:10.1070/PU1968v010n04ABEH003699
2. Pendry, J. B., A. J. Holden, W. J. Stewart, and I. Youngs, "Extremely low frequency plasmons in metallic mesostructures," Physical Review Letters, Vol. 76, 4773-4776, 1996.
doi:10.1103/PhysRevLett.76.4773
3. Pendry, J. B., A. J. Holden, D. J. Robbins, and W. J. Stewart, "Magnetism from conductors and enhanced nonlinear phenomena," IEEE Transactions on Microwave Theory and Techniques, Vol. 47, 2075-2084, 1999.
doi:10.1109/22.798002
4. Smith, D. R., W. J. Padilla, D. C. Vier, S. C. Nemat-Nasser, and S. Schultz, "Composite medium with simultaneously negative permeability and permittivity," Applied Physics Letters, Vol. 84, 4184-4187, 2000.
doi:10.1103/PhysRevLett.84.4184
5. Shelby, R., D. Smith, and S. Schultz, "Experimental verification of a negative index of refraction," Science, Vol. 292, 77-79, 2001.
doi:10.1126/science.1058847
6. Huangfu, J., L. Ran, H. Chen, X. Zhang, K. Chen, T. M. Grzegorczyk, and J. A. Kong, "Experimental confirmation of negative refractive index of a metamaterial composed of Ω-like metallic patterns," Applied Physics Letters, Vol. 84, 1537-1539, 2004.
doi:10.1063/1.1655673
7. Baena, J. D., R. Marques, and F. Medina, "Artificial magnetic metamaterial design by using spiral resonators," Physical Review B, Vol. 69, 014402/1-014402/5, 2004.
doi:10.1103/PhysRevB.69.014402
8. Zhou, J., T. Koschny, L. Zhang, G. Tuttle, and C. M. Soukoulis, "Experimental demonstration of negative index of refraction," Applied Physics Letters, Vol. 88, 221103/1-221103/3, 2006.
9. Kafesaki, M., I. Tsiapa, N. Katsarakis, Th. Koschny, C. M. Soukoulis, and E. N. Economou, "Left-handed metamaterial: The fishnet structure and its variations," Physical Review B, Vol. 75, 235114/1-235114/9, 2007.
doi:10.1103/PhysRevB.75.235114
10. Alici, K. B. and E. Ozbay, "A planar metamaterial: Polarization independent fishnet structure," Photonics and Nanostructures-Fundamentals and Applications, Vol. 6, No. 1, 102-107, 2008.
doi:10.1016/j.photonics.2008.01.001
11. Isik, O. and K. P. Esselle, "Analysis of spiral metamaterials by use of group theory," Metamaterials, Vol. 3, No. 1, 33-43, 2009.
doi:10.1016/j.metmat.2008.10.002
12. Wang, J., S. Qu, Z. Xu, J. Zhang, H. Ma, Y. Yang, and C. Gu, "Broadband planar left-handed metamaterials using split-ring resonator pairs," Photonics and Nanostructures-Fundamentals and Applications, Vol. 7, No. 2, 108-113, 2009.
doi:10.1016/j.photonics.2009.01.001
13. Donzelli, G., A. Vallecchi, F. Capolino, and A. Schuchinsky, "Metamaterial made of paired planar conductors: Particle resonances, phenomena and properties," Metamaterials, Vol. 3, No. 1, 10-27, 2009.
doi:10.1016/j.metmat.2008.12.001
14. Vallecchi, A., F. Capolino, A. G. Schuchinsky, and A. G. Schuchinsky, "2-D isotropic effective negative refractive index metamaterial in planar technology," IEEE Microwave and Wireless Components Letters, Vol. 19, No. 5, 269-271, 2009.
doi:10.1109/LMWC.2009.2017585
15. Wang, J., S. Qu, J. Zhang, H. Ma, Y. Yang, C. Gu, and X.Wu, "A tunable left-handed metamaterial based on modified broadside-coupled split-ring resonators," Progress In Electromagnetics Research Letters, Vol. 6, 35-45, 2009.
doi:10.2528/PIERL08120708
16. Ekmekci, E. and G. Turhan-Sayan, "Comparative investigation of resonance characteristics and electrical size of the double-sided SRR, BC-SRR and conventional SRR type metamaterials for varying substrate parameters," Progress In Electromagnetics Research B, Vol. 12, 35-62, 2009.
doi:10.2528/PIERB08120405
17. Zhou, X., Y. Liu, and X. Zhao, "Low losses left-handed materials with optimized electric and magnetic resonance," Applied Physics A: Materials Science and Processing, Vol. 98, No. 3, 643-649, 2009.
18. Zhu, C., J. -J. Ma, L. Chen, and C. -H. Liang, "Negative index metamaterials composed of triangular open-loop resonator and wire structures," Microwave and Optical Technology Letters, Vol. 51, No. 9, 2009.
19. Sabah, C., "Tunable metamaterial design composed of triangular split ring resonator and wire strip for S- and C- microwave bands," Progress In Electromagnetics Research B, Vol. 22, 341-357, 2010.
doi:10.2528/PIERB10051705
20. Nemer, S., B. Sauviac, B. Bayard, C. Nader, J. Bechara, and A. Khoury, "Modelling resonance frequencies of a multi-turn spiral for metamaterial applications," Progress In Electromagnetics Research C, Vol. 20, 31-42, 2011.
21. Alhawari, A. R. H., A. Ismail, M. A. Mahdi, and R. S. A. R. Abdullah, "Miniaturized ultra-wideband antenna using microstrip negative index metamaterial," Electromagnetics, Vol. 31, No. 6, 404-418, 2011.
doi:10.1080/02726343.2011.590961
22. Kwon, D.-H., D. H. Werner, A. V. Kildishev, and V. M. Shalaev, "Near-infrared metamaterials with dual-band negative-index characteristics," Optics Express, Vol. 15, No. 4, 1647-1652, 2007.
doi:10.1364/OE.15.001647
23. Hu, C. L., Liu, X. Chen, and X. Luo, "Expanding the band of negative permeability of a composite structure with dual-band negative permeability," Optics Express, Vol. 16, No. 26, 21544-21549, 2008.
doi:10.1364/OE.16.021544
24. Hu, C., L. Liu, Z. Zhao, X. Chen, Q. Feng, and X. Luo, "Multimode magnetic responses in NIR and visible ranges," Applied Physics B: Laser and Optics, Vol. 96, No. 2--3, 439-443, 2009.
25. Ekmekci, E. and G. Turhan-Sayan, "A novel dual-band metamaterial structure," PIERS Proceedings, 87-91, Moscow, Russia, August 18--21, 2009.
26. Huang, C., Z. Zhao, Q. Feng, J. Cui, and X. Luo, "Metamaterial composed of wire pairs exhibiting dual band negative refraction," Applied Physics B: Lasers and Optics, Vol. 98, No. 2--3, 365-370, 2009.
27. Gundogdu, T. F., K. Guven, M. Gokkavas, C. M. Soukoulis, and E. Ozbay, "A planar metamaterial with dual-band double-negative response at EHF," IEEE Journal of Selected Topics in Quantum Electronics, Vol. 16, No. 2, 376-379, 2010.
doi:10.1109/JSTQE.2009.2031618
28. Naghipourfar, M. and Z. Atlasbaf, "New dual-band DNG metamaterials," Canadian Journal on Electrical and Electronics Engineering, Vol. 2, No. 2, 47-56, February 2011.
29. Chu, Q.-X. and F.-C. Chen, "A compact dual-band bandpass filter using meandering stepped impedance resonators," IEEE Microwave and Wireless Components Letters, Vol. 18, No. 5, 320-322, May 2008.
doi:10.1109/LMWC.2008.922117
30. Chu, Q.-X. and F.-C. Chen, "A novel dual-band bandpass filter using stepped impedance resonators with transmission zeros," Microwave and Optical Technology Letters, Vol. 50, No. 6, 1466-1468, June 2008.
doi:10.1002/mop.23394
31. Velazquez-Ahumada, M. D. C., J. Martel, F. Medina, and F. Mesa, "Application of stub loaded folded stepped impedance resonators to dual band filter design," Progress In Electromagnetics Research, Vol. 102, 107-124, 2010.
doi:10.2528/PIER10011406
32. Namsang, A. and P. Akkaraekthalin, "Microstrip bandpass filters using end-coupled asymmetrical step-impedance resonators for wide-spurious response," Progress In Electromagnetics Research C, Vol. 14, 53-65, 2010.
doi:10.2528/PIERC10012704
33. Xiao, J.-K. and H.-F. Huang, "New dual-band bandpass filter with compact sir structure," Progress In Electromagnetics Research Letters, Vol. 18, 125-134, 2010.
doi:10.2528/PIERL10082202
34. Zhang, X. Y., C. H. Chan, Q. Xue, and B.-J. Hu, "Dual-band bandpass filter with controllable bandwidths using two coupling paths," IEEE Microwave and Wireless Components Letters, Vol. 20, No. 11, 616-618, November 2010.
doi:10.1109/LMWC.2010.2066553
35. Makimoto, M. and S. Yamashita, Microwave Resonators and Filters for Wireless Communication, Springer-Verlag, 2001.
36. Razalli, M. S., A. Ismail, M. A. Mahdi, and M. N. Bin Hamidon, "Novel compact microstrip ultra-wideband filter utilizing short-circuited stubs with less vias," Progress In Electromagnetics Research, Vol. 88, 91-104, 2008.
doi:10.2528/PIER08102303
37. Chen, F.-C., Q.-X. Chu, and Z.-H. Tu, "Design of compact dual-band bandpass filter using short stub loaded resonator," Microwave and Optical Technology Letters, Vol. 51, No. 4, 959-963, April 2009.
doi:10.1002/mop.24209
38. Li, B., X. Wu, N. Yang, and W. Wu, "Dual-band equal/unequal Wilkinson power dividers based on coupled-line section with short-circuited stub," Progress In Electromagnetics Research, Vol. 111, 163-178, 2011.
39. Kuo, J. T. and C. Y. Tsai, "Periodic stepped-impedance ring resonator (PSIRR) bandpass filter with a miniaturized area and desirable upper stopband characteristics," IEEE Transactions on Microwave Theory and Techniques, Vol. 54, No. 3, 1107-1112, March 2006.
doi:10.1109/TMTT.2005.864121
40. Chen, C. F., T. Y. Huang, and R. B. Wu, "Design of dual-and triple-passband filters using alternately cascaded multiband resonators," IEEE Transactions on Microwave Theory and Techniques, Vol. 54, No. 9, 3550-3558, September 2006.
doi:10.1109/TMTT.2006.880653
41. Weng, M. H., H. W. Wu, and Y. K. Su, "Compact and low-loss dual-band bandpass filter using pseudo-interdigital stepped impedance resonators for WLANs," IEEE Microwave and Wireless Components Letters, Vol. 17, No. 3, 187-189, March 2007.
doi:10.1109/LMWC.2006.890463
42. Chen, F.-C. and Q.-X. Chu, "Novel multistub loaded resonator and its application to high-order dual-band filters," IEEE Transactions on Microwave Theory and Techniques, Vol. 58, No. 6, 1551-1556, June 2010.
doi:10.1109/TMTT.2010.2049161
43. Computer Simulation Technology (CST) Microwave Studio, Version 2010.
44. Hong, J.-S. and M. J. Lancaster, Microstrip Filter for RF/Microwave Applications, Wiley, 2001.
doi:10.1002/0471221619
45. Smith, D. R., S. Shultz, P. Markos, and C. M. Soukoulis, "Determination of effective permittivity and permeability of metamaterials from reflection and transmission coefflcients," Physics Review B, Vol. 65, 195104-195101--95104-195105, 2002.
46. Chen, X., T. M. Grzegorczyk, B.-I. Wu, J. Pacheco, and J. A. Kong, "Robust method to retrieve the constitutive effective parameters of metamaterials," Physical Review E 70, 016608/1-016608/7, 2004.
47. Smith, D. R., D. C. Vier, T. Koschny, and C. M. Soukoulis, "Electromagnetic parameter retrieval from inhomogeneous metamaterials," Physical Review E, Vol. 71, 036617/1-036617/11, 2005.
doi:10.1103/PhysRevE.71.061902
48. Grzegorczyk, T. M., M. Nikku, X. Chen, B.-I.Wu, and J. A. Kong, "Refraction laws for anisotropic media and their application to left-handed metamaterials," IEEE Transactions on Microwave Theory and Techniques, Vol. 53, No. 4, 1443-1450, 2005.
doi:10.1109/TMTT.2005.845206
49. Wu, Q., P. Pan, F.-Y. Meng, L.-W. Li, and J. Wu, "A novel flat lens horn antenna designed based on zero refraction principle of metamaterials," Applied Physics A, Vol. 87, 151-156, 2007.
doi:10.1007/s00339-006-3820-9