volume | PIER Journals

Abstract

In this paper, the characteristics of novel modified composite right/left-handed (CRLH) transmission lines are discussed, and an ultra-wideband (UWB) bandpass filter (BPF) using the modified CRLH transmission lines is presented. Design formulas of a novel modified CRLH unit cell are theoretically derived. Based on the design formulas, the UWB bandpass filter with three unit cells is designed, fabricated, and measured. The measurement results show that the UWB bandpass filter has an insertion loss of less than 1 dB, bandwidths of 2.9~4.9 GHz, and a rejection of greater than 50 dB at 5.8 GHz.

1. Gao, S. S., X. S. Yang, J. P. Wang, S. Q. Xiao, and B. Z. Wang, "Compact ultra-wideband (UWB) bandpass filter using modified stepped impedance resonator," Journal of Electromagnetic Waves and Applications, Vol. 22, No. 4, 514-548, 2008.
doi:10.1163/156939308784150317

2. Chen, Y.-C., C.-H. Lee, and C. G. Hsu, "A compact CPW-fed UWB BPF using combined microstrip SIR," Microwave and Optical Technology Letters, Vol. 51, No. 4, 918-921, Apr. 2009.
doi:10.1002/mop.24199

3. Duong, T. H. and I. S. Kim, "New UWB BPF with steep selectivity based on T-resonator and capacitively coupled λ/4 and λ/2 line sections," Journal of Electromagnetic Engineering and Science, Vol. 9, No. 3, 164-173, Sep. 2009.

4. Huang, J.-Q., Q.-X. Chu, and C.-Y. Liu, "Compact UWB filter based on surface-coupled structure with dual notched bands," Progress In Electromagnetics Research, Vol. 106, 311-319, 2010.
doi:10.2528/PIER10062203

5. Watanabe, K., Z. M. Ma, C. P. Chen, and T. Anada, "An ultra-wideband bandpass filter having sharp skirt property and large attenuations in its stopband," Microwave and Optical Technology Letters, Vol. 51, No. 9, 2093-2097, Jun. 2010.
doi:10.1002/mop.24557

6. Kumar, H. and MD. Upadhayay, "Design of UWB filter with WLAN notch," International Journal of Antennas and Propagation, Vol. 2012, Article ID 971097, 4 pages, 2012.

7. Lin, X. Q., H. F. Ma, D. Bao, and T. J. Cui, "Design and analysis of super-wide bandpass filters using a novel compact meta-structure," IEEE Trans. on Microw. Theory and Tech., Vol. 55, No. 4, 747-753, Apr. 2007.
doi:10.1109/TMTT.2007.892811

8. Gong, J.-Q. and Q.-X. Chu, "SCRLH TL based UWB bandpass filter with widened upper stopband," Journal of Electromagnetic Waves and Applications, Vol. 22, No. 14-15, 1985-1992, 2008.
doi:10.1163/156939308787537982

9. Shen, Y. and C. L. Law, "5.8-GHz suppressed UWB bandpass filter employing modified CRLH-TL of two and three unit cells," Progress In Electromagnetics Research Letters, Vol. 29, 107-113, 2012.
doi:10.2528/PIERL11120206

10. Su, P., X. Lin, R. Zhang, and Y. Fan, "An improved CRLH wideband filter using CSRRS with high stop band rejection," Progress In Electromagnetics Research Letters, Vol. 32, 119-127, 2012.

11. 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 and Propagation Society International Symposium, Vol. 2, 412-415, Jun. 2002.

12. Lai, A., T. Itoh, and C. Caloz, "Composite right/left-handed transmission line metamaterials," IEEE Microwave Magazine, Vol. 5, No. 3, 34-50, 2004.
doi:10.1109/MMW.2004.1337766

13. Caloz, C. and T. Itoh, Electromagnetic Metamaterials: Transmission Line Theory and Microwave Applications, Chapter 3, Wiley, NJ, 2006.

Dr. Gyuje Sung

Dr. Young Kim