A novel structure of dual-composite right/left-handed transmission line (D-CRLH-TL) is proposed in this paper, and its electromagnetic characteristics are investigated in theory and simulation. The dispersion curve of the proposed structure has been derived by using Bloch-Floquet theory. The structure is composed with an "H"-shaped defected ground structure (DGS) and two stubs with rectangular patches, compared with the structure of D-CRLH-TL proposed in paper  and , this structure is simpler and more easily adjusted. Then, an ultra wide-stopband (UWSB) bandstop filter based on the proposed D-CRLH-TL is designed, fabricated, and measured. The simulated and measured results show that the centre frequency of the filter is 5.1 GHz, the bandwidth of stopband is 90.2%, and the filter has sharp transmissions at the two edges of the stop-band. Besides, the designed filter in this paper has a smaller size than traditional ones, and can be easily fabricated.
2. Caloz, C. and T. Itoh, "Application of the transmission line theory of left-handed (LH) materials to the realization of a microstrip LH line," IEEE Antennas Propag. Symp. Dig。, 412-415, San Antonio, TX, 2002.
3. Caloz, C., "Dual composite right/left-handed (D-CRLH) transmission line metamaterial," IEEE Microw. Wireless Compon. Lett., Vol. 16, 585-587, 2006.
4. Caloz, C., S. Abielmona, H. V. Nguyen, and A. Rennings, "Dual composite right/left-handed (D-CRLH) leaky-wave antenna with low beam squinting and tunable group velocity,", Vol. 244, 1219-1226, 2007.
5. Shelby, R. A., D. R. Smith, and S. Schultz, "Experimental verification of a negative index of refraction," Science, Vol. 292, 77-79, 2001.
6. Xu, H.-X., G.-M. Wang, and J.-G. Liang, "Novel CRLH-TL metamaterial and compact microstrip branch-line coupler application," Progress In Electromagnetics Research C, Vol. 20, 173-186, 2011.
7. Ryu, Y. H., J. H. Park, J. H. Lee, J. Y. Kim, and H. S. Tae, "DGS dual composite right/left handed transmission line," IEEE Microw. Wireless Compon. Lett., Vol. 18, 434-436, 2008.
8. Lu, K., "Investigation into the design of novel metamaterial cells and their application in microwave engineering,", Doctoral Dissertation, Air Force Engineering University of China, Xi'an, 2012 .
9. Song, , J., X. Wang, X. You, and B. Cheng, "Design of stripline bandstop filter using stepped-impedance resonator," Electronic Components & Materials, Vol. 31, No. 9, 59-62, 2012.
10. Cui, D., Y. Liu, Y. Wu, S. Li, and C. Yu, "A compact bandstop filter based on two meandered parallel-coupled lines," Progress In Electromagnetics Research, Vol. 121, 271-279, 2011.
11. Huang, X. and C. Cheng, "A novel bandstop filter using square ring dual-mode resonator," Journal of Nanjing University of Posts and Telecommunications, Vol. 29, No. 4, 46-49, 2009.
12. Chiou, Y.-C. and J.-Y. Kuo, "Planar multiband bandpass filter with multimode stepped-impedance resonators," Progress In Electromagnetic Research, Vol. 114, 129-144, 2011.
13. Cheng, D., H.-C. Yin, and H.-X. Zheng, "Investigation on a defected microstrip structure and applications in designing microstrip filters," Journal of Electromagnetic Waves and Application, Vol. 26, No. 10, 1332-1340, 2012.