Skip to main content
Log in

Microstrip BPFs with Increased Selectivity and Asymmetric Frequency Responses

  • Published:
Radioelectronics and Communications Systems Aims and scope Submit manuscript

Abstract

Two symmetrical third-order microstrip bandpass filters (BPF) with all mixed coupling coefficients are proposed and analyzed. The first filter is a combline filter with stepped impedance resonators (SIR) closely spaced to each other. This leads to mixed couplings between adjacent resonators. The cross coupling of the end resonators is also mixed K13 = Km13 + Ke13 (MCC). Its magnetic component Km13 is due to a parasitic magnetic coupling between these resonators. To form the electric coupling component Ke13 a thin microstrip line segment was used that connects the resonators through the capacitive gaps. It was found that such a filter has two adjustable transmission zeros (TZ), which can be located both to the right and left of the central frequency f0 of the bandwidth. The second BPF differs from the first in that its central SIR is replaced by a half-wave through-type resonator, which is included in the filter as a two-port circuit. The used half-wave resonator has a U-shape and it works as the admittance inverter, in addition to the resonance phenomenon. This feature leads to a change in the frequency response of the filter. This filter has two adjustable TZs, which are located on both sides of the center frequency f0 of the bandwidth asymmetrically. The direct and inverse problems for the third-order BPF with all mixed couplings are also solved. The solution is based on the conductance matrix [Ỹ] and its minor M31. The direct problem solution makes it possible to determine the TZs of the filter using the given coupling coefficients. In the inverse problem, the filter’s coupling coefficients are determined by the specified TZs. The samples of two experimental filters and measuring frequency responses are presented.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1.
Fig. 2.
Fig. 3.
Fig. 4.

Similar content being viewed by others

References

  1. A. V. Zakharov, S. A. Rozenko, "Duplexer designed on the basis of microstrip filters using high dielectric constant substrates," J. Commun. Technol. Electron., v.57, n.6, p.649 (2012). DOI: https://doi.org/10.1134/S1064226912030187.

    Article  Google Scholar 

  2. J.-S. Hong, M. J. Lancaster, "Microstrip cross-coupled trisection bandpass filters with asymmetric frequency characteristics," IEE Proc. - Microwaves, Antennas Propag., v.146, n.1, p.84 (1999). DOI: https://doi.org/10.1049/ip-map:19990146.

    Article  Google Scholar 

  3. R. M. Kurzrok, "General three-resonator filters in waveguide," IEEE Trans. Microw. Theory Tech., v.14, n.1, p.46 (1966). DOI: https://doi.org/10.1109/TMTT.1966.1126154.

    Article  Google Scholar 

  4. R. Hershtig, R. Levy, K. Zaki, "Synthesis and Design of Cascaded Trisection (CT) Dielectric Resonator Filters," in 27th European Microwave Conference, 1997 (IEEE, Washington). DOI: https://doi.org/10.1109/EUMA.1997.337890.

    Chapter  Google Scholar 

  5. C.-C. Yang, C.-Y. Chang, "Microstrip cascade trisection filter," IEEE Microw. Guid. Wave Lett., v.9, n.7, p.271 (1999). DOI: https://doi.org/10.1109/75.774144.

    Article  Google Scholar 

  6. R. M. Kurzrok, "General four-resonator filters at microwave frequencies," IEEE Trans. Microw. Theory Tech., v.MTT-14, n.6, p.295 (1966). DOI: https://doi.org/10.1109/TMTT.1966.1126254.

    Article  Google Scholar 

  7. R. J. Cameron, C. M. Kudsia, R. R. Mansour, Microwave Filters for Communication Systems (John Wiley & Sons, Inc., Hoboken, NJ, 2018). DOI: https://doi.org/10.1002/9781119292371.

    Book  Google Scholar 

  8. K. Ma, J.-G. Ma, K. S. Yeo, M. A. Do, "A compact size coupling controllable filter with separate electric and magnetic coupling paths," IEEE Trans. Microw. Theory Tech., v.54, n.3, p.1113 (2006). DOI: https://doi.org/10.1109/TMTT.2005.864118.

    Article  Google Scholar 

  9. A. Zakharov, S. Rozenko, S. Litvintsev, M. Ilchenko, "Trisection bandpass filter with mixed cross-coupling and different paths for signal propagation," IEEE Microw. Wirel. Components Lett., v.30, n.1, p.12 (2020). DOI: https://doi.org/10.1109/LMWC.2019.2957207.

    Article  Google Scholar 

  10. A. V. Zakharov, S. N. Litvintsev, M. Ilchenko, "Trisection bandpass filters with all mixed couplings," IEEE Microw. Wirel. Components Lett., v.29, n.9, p.592 (2019). DOI: https://doi.org/10.1109/LMWC.2019.2929650.

    Article  Google Scholar 

  11. S. Tamiazzo, G. Macchiarella, "Synthesis of cross-coupled filters with frequency-dependent couplings," IEEE Trans. Microw. Theory Tech., v.65, n.3, p.775 (2017). DOI: https://doi.org/10.1109/TMTT.2016.2633258.

    Article  Google Scholar 

  12. P. Zhao, K. Wu, "Cascading fundamental building blocks with frequency-dependent couplings in microwave filters," IEEE Trans. Microw. Theory Tech., v.67, n.4, p.1432 (2019). DOI: https://doi.org/10.1109/TMTT.2019.2895532.

    Article  Google Scholar 

  13. L. Szydlowski, A. Lamecki, M. Mrozowski, "Coupled-resonator filters with frequency-dependent couplings: Coupling matrix synthesis," IEEE Microw. Wirel. Components Lett., v.22, n.6, p.312 (2012). DOI: https://doi.org/10.1109/LMWC.2012.2197386.

    Article  Google Scholar 

  14. L. Szydlowski, N. Leszczynska, A. Lamecki, M. Mrozowski, "A substrate integrated waveguide (SIW) bandpass filter in a box configuration with frequency-dependent coupling," IEEE Microw. Wirel. Components Lett., v.22, n.11, p.556 (2012). DOI: https://doi.org/10.1109/LMWC.2012.2221690.

    Article  Google Scholar 

  15. P. Chu, W. Hong, L. Dai, H. Tang, J. Chen, Z. Hao, X. Zhu, K. Wu, "A planar bandpass filter implemented with a hybrid structure of substrate integrated waveguide and coplanar waveguide," IEEE Trans. Microw. Theory Tech., v.62, n.2, p.266 (2014). DOI: https://doi.org/10.1109/TMTT.2013.2294861.

    Article  Google Scholar 

  16. W. Shen, L.-S. Wu, X.-W. Sun, W.-Y. Yin, J.-F. Mao, "Novel substrate integrated waveguide filters with mixed cross coupling (MCC)," IEEE Microw. Wirel. Components Lett., v.19, n.11, p.701 (2009). DOI: https://doi.org/10.1109/LMWC.2009.2032007.

    Article  Google Scholar 

  17. M. Hoft, T. Shimamura, "Design of symmetric trisection filters for compact low-temperature Co-fired ceramic realization," IEEE Trans. Microw. Theory Tech., v.58, n.1, p.165 (2010). DOI: https://doi.org/10.1109/TMTT.2009.2035870.

    Article  Google Scholar 

  18. R. Levy, "New cascaded trisections with resonant cross-couplings (CTR Sections) applied to the design of optimal filters," in IEEE MTT-S International Microwave Symposium Digest (IEEE, Washington). DOI: https://doi.org/10.1109/mwsym.2004.1336007.

    Chapter  Google Scholar 

  19. A. V. Zakharov, M. Y. Ilchenko, L. S. Pinchuk, "Coupling coefficient of quarter-wave resonators as a function of parameters of comb stripline filters," Radioelectron. Commun. Syst., v.58, n.6, p.284 (2015). DOI: https://doi.org/10.3103/S0735272715060060.

    Article  Google Scholar 

  20. A. V. Zakharov, M. E. Il’chenko, "Pseudocombline bandpass filters based on half-wave resonators manufactured from sections of balanced striplines," J. Commun. Technol. Electron., v.60, n.7, p.801 (2015). DOI: https://doi.org/10.1134/S1064226915060182.

    Article  Google Scholar 

  21. C.-L. Hsu, C.-H. Yu, J.-T. Kuo, "Microstrip trisection filters with quasi-elliptic and flat group delay responses," in 2012 4th International High Speed Intelligent Communication Forum (IEEE, Washington). DOI: https://doi.org/10.1109/HSIC.2012.6212988.

    Chapter  Google Scholar 

  22. B.-W. Kim, S.-W. Yun, "Varactor-tuned combline bandpass filter using step-impedance microstrip lines," IEEE Trans. Microw. Theory Tech., v.52, n.4, p.1279 (2004). DOI: https://doi.org/10.1109/TMTT.2004.825626.

    Article  Google Scholar 

  23. A. V. Zakharov, M. E. Il’Chenko, "A new approach to designing varicap-tuned filters," J. Commun. Technol. Electron., v.55, n.12, p.1424 (2010). DOI: https://doi.org/10.1134/S1064226910120156.

    Article  Google Scholar 

  24. F. Zhu, W. Hong, J.-X. Chen, K. Wu, "Quarter-wavelength stepped-impedance resonator filter with mixed electric and magnetic coupling," IEEE Microw. Wirel. Components Lett., v.24, n.2, p.90 (2014). DOI: https://doi.org/10.1109/LMWC.2013.2290225.

    Article  Google Scholar 

  25. G. L. Matthaei, L. Young, E. M. T. Jones, Microwave Filters, Impedance-Matching Networks, and Coupling Structures (Artech House Books, New York, 1980).

    Google Scholar 

  26. S. B. Cohn, "Direct-coupled-resonator filters," Proc. IRE, v.45, n.2, p.187 (1957). DOI: https://doi.org/10.1109/JRPROC.1957.278389.

    Article  Google Scholar 

  27. G. L. Matthaei, "Direct-coupled bandpass-filters with lo/4 resonators," in 1958 IRE National Convention Record (IRE, New York, 1958).

    Google Scholar 

  28. J.-S. Hong, Microstrip Filters for RF/Microwave Applications (Wiley, New Jersey, 2011). URI: https://www.amazon.com/Microstrip-Filters-Microwave-Applications-Engineering-ebook/dp/B005CD1DTC.

    Book  Google Scholar 

  29. H. Wang, Q.-X. Chu, "An inline coaxial quasi-elliptic filter with controllable mixed electric and magnetic coupling," IEEE Trans. Microw. Theory Tech., v.57, n.3, p.667 (2009). DOI: https://doi.org/10.1109/TMTT.2009.2013290.

    Article  Google Scholar 

  30. Q.-X. Chu, H. Wang, "A compact open-loop filter with mixed electric and magnetic coupling," IEEE Trans. Microw. Theory Tech., v.56, n.2, p.431 (2008). DOI: https://doi.org/10.1109/TMTT.2007.914642.

    Article  Google Scholar 

  31. A. V. Zakharov, M. E. Il’сhenko, V. N. Korpach, "Features of the coupling coefficients of planar stepped-impedance resonators at higher resonance frequencies and application of such resonators for suppression of spurious passbands," J. Commun. Technol. Electron., v.59, n.6, p.550 (2014). DOI: https://doi.org/10.1134/S1064226914060217.

    Article  Google Scholar 

  32. A. V. Zakharov, M. Y. Ilchenko, L. S. Pinchuk, "Coupling coefficients of step-impedance resonators in stripeline band-pass filters of array type," Radioelectron. Commun. Syst., v.57, n.5, p.217 (2014). DOI: https://doi.org/10.3103/S0735272714050045.

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to A. V. Zakharov.

Ethics declarations

ADDITIONAL INFORMATION

A. V. Zakharov, S. A. Rozenko, S. N. Litvintsev, and L. S. Pinchuk

The authors declare that they have no conflict of interest.

The initial version of this paper in Russian is published in the journal “Izvestiya Vysshikh Uchebnykh Zavedenii. Radioelektronika,” ISSN 2307-6011 (Online), ISSN 0021-3470 (Print) on the link http://radio.kpi.ua/article/view/S0021347020070031 with DOI: https://doi.org/10.20535/S0021347020070031

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Zakharov, A.V., Rozenko, S.A., Litvintsev, S.N. et al. Microstrip BPFs with Increased Selectivity and Asymmetric Frequency Responses. Radioelectron.Commun.Syst. 63, 353–367 (2020). https://doi.org/10.3103/S0735272720070031

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.3103/S0735272720070031

Navigation