A new method of designing balanced (differential) bandpass filters (BPFs) with high selectivity and common-mode suppression is proposed and implemented by taking advantage of the existence of multiple substrate integrated waveguide cavity modes. The major design concept is by properly choosing, feeding and coupling dual-mode cavities operating at TE₁₀₂ and TE₂₀₁ modes so as to not only provide capabilities to realise the desired differential-mode passband associated with two transmission zeros, but also generate high common-mode suppression over a wide range. Two X-band BPFs with different internal coupling mechanisms are then proposed and designed. The two design examples having the same centre frequency of 10 Hz and respective passband width of 300 and 270 Hz are fabricated for demonstration. High selectivity is observed for both filters. Meanwhile, c is ∼37 dB for the first design example, whereas it is improved to 48.5 dB for the second one with multi-layered structure. Good agreement can be observed between simulated and measured performances in the authors’ study.

References

1. 1)
  - X.H. Wang , Q. Xue , W.W. Choi . A Novel ultra-wideband differential filter based on double-sided parallel-strip line. IEEE Microw. Wirel. Compon. Lett. , 8 , 471 - 473
2. 2)
  - 1. Feng, W.J., Che, W.Q., Eibert, T.F., Xue, Q.: ‘Compact wideband differential bandpass filter based on the double-sided parallel-strip line and transversal signal-interaction concepts’, IET Microw., Antennas Propag., 2012, 6, (2), pp. 186–195 (doi: 10.1049/iet-map.2011.0400).
3. 3)
  - 4. Rawat, K., Ghannouchi, F.M.: ‘Design methodology for dual-band Doherty power amplifier with performance enhancement using dual-band offset lines’, IEEE Trans. Ind. Electron., 2012, 59, (12), pp. 4831–4842 (doi: 10.1109/TIE.2011.2176695).
4. 4)
  - 7. Sakhnenko, S., Orlenko, D., Markov, K., Yatsenko, A.: ‘Low profile LTCC balanced filter based on a lumped elements balun for WiMAX applications’. Proc. IEEE MTT-S Int. Microwave Symposium Digest, 2008, pp. 1111–1114.
5. 5)
  - 16. Chen, J.-X., Shao, C., Lu, Q.-Y., Tang, H., Bao, Z.-H.: ‘Compact LTCC balanced bandpass filter using distributed-element resonator’, Electron. Lett., 2013, 49, (5), pp. 354–356 (doi: 10.1049/el.2012.4071).
6. 6)
  - 26. Ho, M.-H., Li, C.-S.: ‘Novel balanced bandpass filters using substrate integrated half-Mode waveguide’, IEEE Microw. Wirel. Compon. Lett., 2012, 23, (2), pp. 78–80 (doi: 10.1109/LMWC.2013.2238911).
7. 7)
  - 27. Chen, M.-Y., Hong, W., Ho, M.-H.: ‘Balanced BPF design using the substrate integrated waveguide’. Asia–Pacific Microwave Conf., 2012, pp. 25–27.
8. 8)
  - 22. Wu, X.-H., Chu, Q.-X., Guo, X.-X.: ‘A wideband balanced bandpass filter with common-mode suppression using defected ground structure’. Int. Microwave and Millimeter Wave Technology Conf., 2012, pp. 1–4.
9. 9)
  - 3. Wang, X.H., Zhang, H., Wang, B.Z.: ‘A novel ultra-wideband differential filter based on microstrip line structures’, IEEE Microw. Wirel. Compon. Lett., 2013, 23, (3), pp. 128–130 (doi: 10.1109/LMWC.2013.2243719).
10. 10)
  - T.B. Lim , L. Zhu . Highly selective differential-mode wideband bandpass filter for UWB application. IEEE Microw. Wirel. Compon. Lett. , 3 , 133 - 135
11. 11)
  - 6. Song, K., Xue, Q.: ‘Ultra-wideband (UWB) ring-cavity multiple-way parallel power divider’, IEEE Trans. Ind. Electron., 2013, 60, (10), pp. 4737–4745 (doi: 10.1109/TIE.2012.2208441).
12. 12)
  - 32. Collin, R.E.: ‘Foundations for microwave engineering’ (Mc-Graw-Hill, New York, 1992).
13. 13)
  - C.H. Wu , C.H. Wang , C.H. Chen . Balanced coupled-resonator bandpass filters using multisection resonators for common-mode suppression and stopband extension. IEEE Trans. Microw. Theory Tech. , 8 , 1756 - 1763
14. 14)
  - 24. Piloto, A., Leahy, K., Flanick, B., Zaki, K.A.: ‘Waveguide filters having a layered dielectric structures’, U.S. Patent 5382931, January 1995.
15. 15)
  - 10. Shi, S., Choi, W.-W., Che, W., Tam, K.-W., Xue, Q.: ‘Ultra-wideband differential bandpass filter with narrow notched band and improved common-mode suppression by DGS’, IEEE Microw. Wirel. Compon. Lett., 2012, 22, (4), pp. 185–187 (doi: 10.1109/LMWC.2012.2187885).
16. 16)
  - 33. Hong, J.-S., Lancaster, M.J.: ‘Microstrip filters for RF/microwave applications’ (Wiley, New York, 2001).
17. 17)
  - 28. Chen, J., Chen, J.-X., Chu, H., Bao, Z.-H.: ‘A novel X-band differential bandpass filter based on oversized substrate integrated waveguide cavity’. Cross Strait Quad-Regional Radio Science and Wireless Technology Conf., 2013, pp. 62–65.
18. 18)
  - 8. Lu, Y.-J., Chen, S.-Y., Hsu, P.: ‘A differential-mode wideband bandpass filter with enhanced common-mode suppression using slotline resonator’, IEEE Microw. Wirel. Compon. Lett., 2012, 22, (10), pp. 503–505 (doi: 10.1109/LMWC.2012.2218279).
19. 19)
  - 6. Lee, C.-H., Hsu, C.-I.G., Chen, C.-J.: ‘Band-notched balanced UWB BPF with stepped-impedance slotline multi-mode resonator’, IEEE Microw. Wirel. Compon. Lett., 2012, 22, (4), pp. 182–184 (doi: 10.1109/LMWC.2012.2188019).
20. 20)
  - J. Shi , Q. Xue . Balanced bandpass filters using center-loaded half-wavelength resonators. IEEE Trans. Microw. Theory Tech. , 4 , 970 - 977
21. 21)
  - D.E. Bockelman , W.R. Eisenstant . Combined differential and common-mode scattering parameters: theory and simulation. IEEE Trans. Microw. Theory Tech. , 7 , 1530 - 1539
22. 22)
  - 2. Shao, Y.Z., Wing, S.C., Yuk, S.W.: ‘Reconfigurable RF quadrature patch hybrid coupler’, IEEE Trans. Ind. Electron., 2013, 60, (8), pp. 3349–3359.
23. 23)
  - U. Rosenberg , S. Amari . Novel design possibilities for dual-mode filters without intracavity couplings. IEEE Microw. Wirel. Compon. Lett. , 296 - 298
24. 24)
  - 9. Abbosh, A.M.: ‘Ultra-wideband balanced bandpass filter’, IEEE Microw. Wirel. Compon. Lett., 2010, 21, (9), pp. 480–480 (doi: 10.1109/LMWC.2011.2162620).
25. 25)
  - 6. Yeung, L.K., Wu, K.L.: ‘An integrated RF balanced-filter with enhanced rejection characteristics’. IEEE MTT-S Int. Microwave Symposium Digest, 2005, pp. 713–716.
26. 26)
  - 7. Wu, X.H., Chu, Q.X.: ‘Compact differential ultra-wideband bandpass filter with common-mode suppression’, IEEE Microw. Wirel. Compon. Lett., 2012, 22, (9), pp. 456–458 (doi: 10.1109/LMWC.2012.2213075).
27. 27)
  - 31. Shen, T.-M., Huang, T.-Y., Chen, C.-F., Wu, R.-B.: ‘A laminated waveguide magic-T with bandpass filter response in multilayer LTCC’, IEEE Trans. Microw. Theory Tech., 2011, 59, (3), pp. 584–592 (doi: 10.1109/TMTT.2011.2104973).
28. 28)
  - H.C. Chen , C.H. Tsai , T.L. Wu . A compact and embedded balanced bandpass filter with wideband common-mode suppression on wireless SiP. IEEE Trans. Compon. Packag. Technol. , 6 , 1030 - 1038
29. 29)
  - 4. Vélez, P., Naqui, J., -Prieto, A.F., et al: ‘Differential bandpass filter with common-mode suppression based on open split ring resonators and open complementary split ring resonators’, IEEE Microw. Wirel. Compon. Lett., 2013, 23, (1), pp. 471–473 (doi: 10.1109/LMWC.2012.2236083).
30. 30)
  - 3. Lau, P.-Y., Yung, K.K.-O., Yung, E.K.-N.: ‘A low-cost printed CP patch antenna for RFID smart bookshelf in library’, IEEE Trans. Ind. Electron., 2010, 57, (5), pp. 1583–1589 (doi: 10.1109/TIE.2009.2035992).
31. 31)
  - 8. Feng, W.J., Che, W.Q., Ma, Y.L., Xue, Q.: ‘Compact wideband differential bandpass filters using half-wavelength ring resonator’, IEEE Microw. Wirel. Compon. Lett., 2013, 23, (2), pp. 81–83 (doi: 10.1109/LMWC.2013.2239632).
32. 32)
  - 29. Chu, P., Hong, W., Wang, K., et al.: ‘Balanced substrate integrated waveguide filter’, IEEE Trans. Microw. Theory Tech., 2014, 62, (4), pp. 824–831 (doi: 10.1109/TMTT.2014.2307055).
33. 33)
  - 25. Hui, J.N., Feng, W.J., Che, W.Q.: ‘Balun bandpass filter based on multilayer substrate integrated waveguide power divider’, Electron. Lett., 2012, 48, (10), pp. 571–573 (doi: 10.1049/el.2012.0479).

Balanced substrate integrated waveguide bandpass filter with high selectivity and common-mode suppression

References

Related content