volume | PIER Journals

Abstract

A novel balanced filter circuit with wideband common mode suppression using coupled lines is proposed in this paper. A wideband filter with half open stubs is used to realize two transmission zeros for the differential mode passband. The common mode can be suppressed over 15 dB from 0 GHz to 3f₀ (f₀ is the center frequency of the passband) with insertion loss greater than 15 dB over the upper stopband. A balanced filter with 3-dB fractional bandwidths of 38% is designed and fabricated. Good agreement can be observed between measured results and theoretical expectations.

1. Eisenstant, W. R., B. Stengel, and B. M. Thompson, Microwave Differential Circuit Design Using Mixed-mode S-parameters, Artech House, 2006.

2. Feng, W. J., W. Q. Che, and Q. Xue, "The proper balance: Overview of microstrip wideband balanced circuits with wideband common mode suppression," IEEE Microw. Magazine, Vol. 16, No. 5, 55-68, Jun. 2015.
doi:10.1109/MMM.2015.2408275 Google Scholar

3. Wu, C.-H., C.-H. Wang, and C. H. Chen, "Balanced coupled-resonator bandpass filters using multi-section resonators for common-mode suppression and stopband extension," IEEE Trans. Microw. Theory Techn., Vol. 55, No. 8, 1756-1763, Aug. 200.
doi:10.1109/TMTT.2007.901609 Google Scholar

4. Shi, J. and Q. Xue, "Dual-band and wide-stopband single-band balanced bandpass filters with high selectivity and common-mode suppression," IEEE Trans. Microw. Theory Techn., Vol. 58, No. 8, 2204-2212, Aug. 2010.
doi:10.1109/TMTT.2010.2052959 Google Scholar

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, Oct. 2009. Google Scholar

6. Wu, X. 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, Sep. 2012.
doi:10.1109/LMWC.2012.2213075 Google Scholar

7. Abbosh, A. M., "Ultrawideband balanced bandpass filter," IEEE Microw. Wireless Compon. Lett., Vol. 21, No. 9, 480-482, Sep. 2011.
doi:10.1109/LMWC.2011.2162620 Google Scholar

8. Lu, Y.-J., S.-Y. Chen, and P. Hsu, "A differential-mode wideband bandpass filter with enhanced common-mode suppression using slotline resonator," IEEE Microw. Wireless Compon. Lett., Vol. 22, No. 10, 503-505, Oct. 2012.
doi:10.1109/LMWC.2012.2218279 Google Scholar

9. Lee, C.-H., C. I. G. Hsu, and C.-J. Chen, "Band-notched balanced UWB BPF with stepped-impedance slotline multi-mode resonator," IEEE Microw. Wireless Compon. Lett., Vol. 22, No. 4, 182-184, Apr. 2012.
doi:10.1109/LMWC.2012.2188019 Google Scholar

10. Shi, J., J. X. Chen, Q. Y. Lu, Y. Peng, and Z. Bao, "Compact low-loss wideband differential bandpass filter with high common-mode suppression," IEEE Microw. Wireless Compon. Lett., Vol. 23, No. 9, 480-482, Sep. 2013.
doi:10.1109/LMWC.2013.2274996 Google Scholar

11. 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, Aug. 2010.
doi:10.1109/LMWC.2010.2050869 Google Scholar

12. Feng, W. J., W. Q. Che, T. F. Eibert, and Q Xue, "Compact wideband differential bandpass filter based on the double-sided parallel-strip line and transversal signal-interaction concepts," IET Microw. Antennas Propag., Vol. 6, No. 2, 186-195, Apr. 2012.
doi:10.1049/iet-map.2011.0400 Google Scholar

13. Feng, W. J., W. Q. Che, Y. L. Ma, and Q Xue, "Compact wideband differential bandpass filter using half-wavelength ring resonator," IEEE Microw. Wireless Compon. Lett., Vol. 23, No. 2, 81-83, Feb. 2013.
doi:10.1109/LMWC.2013.2239632 Google Scholar

14. Feng, W. J. and W. Q. Che, "Novel wideband differential bandpass filters based on T-shaped structure," IEEE Trans. Microw. Theory Techn., Vol. 60, No. 6, 1560-1568, Jun. 2012.
doi:10.1109/TMTT.2012.2188538 Google Scholar

15. Martınez, J. J. S. and E. M. Segura, "Analytical design of wire-bonded multiconductor transmission-line-based ultra-wideband differential bandpass filters," IEEE Trans. Microw. Theory Techn., Vol. 62, No. 10, 2308-2315, Oct. 2014.
doi:10.1109/TMTT.2014.2345338 Google Scholar

16. Matthaei, G., L. Young, and E. M. T. Jones, Microwave Filters, Impedance Matching Networks and Coupling Structures, Section 5, 222-224, Artech House Inc., Norwood, MA, 1985.

Dr. Kuan Deng

Dr. Zhengyu Chen