volume | PIER Journals

Abstract

A wideband differential bandpass filter (BPF) with differential mode passband and common mode suppression is proposed and implemented on microstrip lines for wideband application in this letter. The initial BPF is similar to a single ring resonator with two unequal feed lines which have 180^o separation and T-shaped stubs are loaded on the ring resonator to form an improved one for better performances. The lengths and widths of these stubs can be adjusted to produce a highly selectivity under the differential mode and improved attenuation under the common mode. This simple, compact structure is easy for construct without any coupling structure. Finally, a microstrip differential wideband BPF is designed, simulated, fabricated, and measured. The presented differential BPF has a 3-dB fractional bandwidth (FBW) of 38% for the differential mode and insertion loss greater than 17 dB for common mode. Good agreement between simulated and measured results is obtained.

1. Wang, X. H. , Q. Xue, and W. W. Choi, "A novel ultra-wideband differential filter based on double-sided parallel-strip line," IEEE Microw. Wireless Compon. Lett., Vol. 20, No. 8, 471-473, 2010.
doi:10.1109/LMWC.2010.2050869

2. Lim, T. B. and L. Zhu, "Differential-mode ultra-wideband bandpass filter on microstrip line," Electron. Lett., Vol. 45, No. 22, 1124-1125, 2009.
doi:10.1049/el.2009.1416

3. Lim, T. B. and L. Zhu, "Highly selective differential-mode wideband bandpass filter for UWB application," IEEE Microw. Wireless Compon. Lett., Vol. 21, No. 3, 133-135, 2011.
doi:10.1109/LMWC.2011.2104357

4. Naqui, J., A. F. Prieto, M. D. Sindreu, F. Mesa, J. Matrel, F. Medina, and F. Martin, "Common-mode suppression in microstrip differential lines by means of complementary split ring resonators: theory and applications," IEEE Trans. on Microwave Theory & Tech., Vol. 60, No. 10, 3023-3034, 2012.
doi:10.1109/TMTT.2012.2209675

5. Lim, T. B. and L. Zhu, "A differential-mode wideband bandpass filter on microstrip line for UWB application," IEEE Microw. Wireless Compon. Lett., Vol. 19, No. 10, 632-634, 2009.
doi:10.1109/LMWC.2009.2029739

6. Shi, S. Y., W. W. Choi, W. Q. Che, K. W. Tam, and Q. Xue, "Ultra-wideband differential bandpass filter with narrow notched band and improved common-mode suppression by DGS," IEEE Microw. Wireless Compon. Lett., Vol. 22, No. 4, 185-187, 2012.
doi:10.1109/LMWC.2012.2187885

7. Zhu, H. T., W. J. Feng, W. Q. Che, Q. Xue, "Ultra-wideband differential bandpass filter based on transversal signal-interference concept," Electron. Lett., Vol. 47, No. 18, 1033-1035, 2011.
doi:10.1049/el.2011.2088

8. Wu, C. H., C. H.Wang, and C. H. Chen, "Novel balanced coupled-line bandpass filters with common-mode noise suppression," IEEE Trans. on Microwave Theory & Tech., Vol. 55, No. 2, 287-295, 2007.
doi:10.1109/TMTT.2006.889147

9. Wu, X. H. and Q. X. Chu, "Compact differential ultra-wideband bandpass filter with common-mode suppression," IEEE Microw. Wireless Compon. Lett., Vol. 22, No. 9, 456-458, 2012.
doi:10.1109/LMWC.2012.2213075

10. Shi, J. and Q. Xu, "Dual-band and wide-stopband single-band balanced bandpass filters with high selectivity and common-mode suppression," IEEE Trans. on Microwave Theory & Tech., Vol. 58, No. 8, 2204-2212, 2010.
doi:10.1109/TMTT.2010.2052959

11. Lim, S. C., C. Y, and Yeh, "Stopband-extended balanced filters using both l/4 and l/2 SIRs with common-mode suppression and improved passband selectivity," Progress In Electromagnetics Research, Vol. 128, 215-228, 2012.

12. Wu, S. M., C. T. Kuo, and C. H. Chen, "Very compact full differential bandpass filter with transformer integrated using integrated passive device technology," Progress In Electromagnetics Research Letters, Vol. 113, 251-267, 2011.

13. Wu, S. M., C. T. Kuo, P. Y. Lyu, Y. L. Shen, and C. I. Chien, "Miniaturization design of full differential bandpass filter with coupled resonators using embedded passive device technology," Progress In Electromagnetics Research Letters, Vol. 121, 365-379, 2011.

14. Nicollini, G., F. Moretti, and M. Conti, "High frequency fully differential filter using operation amplifiers without common-mode feedback," IEEE J. Solid-State Circuits, Vol. 24, No. 3, 803-813, 1989.
doi:10.1109/4.32043

15. Wang, H., W. Kang, C. Miao, and W. Wu, "Cross-shaped UWB bandpass filter with sharp skirt and notched band," Electron. Lett., Vol. 48, No. 2, 96-97, 2012.
doi:10.1049/el.2011.3694

16. Feng, W. J., W. Q. Che, and Q. Xue, "Compact ultra-ideband bandpass filter implemented with stepped impedance resonators and T-shaped line," International Conference on Micro. Millimeter Wave Tech., (ICMMT), 44-47, 2010.

17. Liu, G. Q., L. S. Wu, and W. Y. Yin, "A compact microstrip ratrace coupler with modified lange and T-shaped arms," Progress In Electromagnetics Research Letters, Vol. 115, 509-523, 2011.

18. Xie, J.-J., Y.-Z. Yin, S.-L. Pan, and L. Sun, "A novel circular slot antenna with two pairs of T-shaped slots for WLAN/WiMAX applications," Progress In Electromagnetics Research Letters, Vol. 32, 49-57, 2012.

19. Chen, L.-N., Y.-C. Jiao, Z. Zhang, F.-S. Zhang, and Y.-Y. Chen, "Miniaturized dual-mode substrate integrated waveguide (SIW) band-pass filters loaded by double/single T-shaped structures," Progress In Electromagnetics Research Letters, Vol. 29, 65-74, 2012.
doi:10.2528/PIERL11112602

20. Kang, L., Y.-Z. Yin, S.-T. Fan, and S.-J. Wei, "A novel rectangular slot antenna with embedded self-similar T-shaped strips for WLAN applications," Progress In Electromagnetics Research Letters, Vol. 15, 19-26, 2010.
doi:10.2528/PIERL10040908

21. Li, J.-F. and Q.-X. Chu, "Proximity-FED MIMO antenna with two printed IFAS and a wideband T-shaped neutralization line," Progress In Electromagnetics Research M, Vol. 21, 279-294, 2011.
doi:10.2528/PIERM11091509

22. Reed, J. and G. J. Wheeler, "A method of analysis of symmetrical four-port networks," IRE Trans. on Microwave Theory & Tech., Vol. 4, No. 4, 246-252, 1956.
doi:10.1109/TMTT.1956.1125071

Dr. Hui Wang

Dr. Wei Kang

Dr. Guo Yang

Dr. Wen Wu