Accessible Requires Authentication Published by De Gruyter October 18, 2019

Folded W-Band Waveguide Filters with Resonant Coupling Apertures for the Generation of Additional Transmission Zeros

Daniel Miek, Ana Morán-López, Jorge A. Ruiz-Cruz ORCID logo and Michael Höft
From the journal Frequenz

Abstract

In this paper the realization of multiple additional transmission zeros in folded W-band waveguide filters is discussed. The transmission zeros (TZs) can be placed symmetrically as well as asymmetrically in the near passband region of the filter and arise due to a resonant coupling between source and / or load. Third and fourth order filter set-ups are presented, showing in total between three and six TZs. These zeros can be used to improve the selectivity of the filter without increasing the overall order. The filter design and realization process is discussed. Subsequently, the measurement results are compared with simulation, showing good agreement. As the filters are designed for the W-band, the manufacturing process is connected with some difficulties which are addressed within this paper as well.

Acknowledgements

This work was partially supported by the Spanish Government under Grant TEC2016-76070-C3-1-R (AEI/FEDER, UE)

References

[1] R. J. Cameron, “Advanced coupling matrix synthesis techniques for microwave filters,” IEEE Trans. Microw. Theory Tech., vol. 51, no. 1, pp. 1–10, Jan. 2003.10.1109/TMTT.2002.806937 Search in Google Scholar

[2] H. Bell, “Canonical asymmetric coupled-resonator filters,” IEEE Trans. Microw. Theory Tech., vol. 30, no. 9, pp. 1335–1340, Sep. 1982.10.1109/TMTT.1982.1131257 Search in Google Scholar

[3] S. Amari and U. Rosenberg, “Characteristics of cross (bypass) coupling through higher/lower order mode and their applications in elliptic filter design,” IEEE Trans. Microw. Theory Tech., vol. 53, no. 10, pp. 3135–3141, Oct. 2005.10.1109/TMTT.2005.855359 Search in Google Scholar

[4] J. R. Montejo-Garai and J. M. Rebollar, “Synthesis and design of N-order filters with N-transmission zeros by means of source–load direct coupling,” Microwave Opt. Technol. Lett., vol. 29, no. 4, pp. 248–252, Apr. 2001.10.1002/mop.1145 Search in Google Scholar

[5] J. Bornemann, S. Amari, and R. Vahldieck, “A flexible S-matrix algorithm for the design of folded waveguide filters,” in 2005 European Microwave Conference (EuMC), vol. 1. IEEE, Oct. 2005. Search in Google Scholar

[6] L. Szydlowski, A. Lamecki, and M. Mrozowski, “A novel coupling matrix synthesis technique for generalized Chebyshev filters with resonant source–load connection,” IEEE Trans. Microw. Theory Tech., vol. 61, no. 10, pp. 3568–3577, Oct. 2013.10.1109/TMTT.2013.2280113 Search in Google Scholar

[7] D. Miek, A. Reinhardt, F. Daschner, and M. Höft, “Improved fully canonical W-band waveguide filter,” Proc. International Microwave Symposium (IMS), Philadephia, United States, pp. 1245–1248, Jun. 2018. Search in Google Scholar

[8] D. Miek, A. Morán-López, J. A. Ruiz-Cruz, and M. Höft, “Improved fully canonical phase equalized W-band waveguide filter with dispersive coupling inverter,” in 2018 48th European Microwave Conference (EuMC). IEEE, Sep. 2018, pp. 166–169. Search in Google Scholar

[9] D. Miek and M. Höft, “Realization of folded W-band waveguide filters with additional asymmetric resonant transmission zeros,” in 2019 12th German Microwave Conference (GeMiC). IEEE, Mar. 2019. Search in Google Scholar

[10] I. Awai and Y. Zhang, “Coupling coefficients of resonators - An intuitive way of its understanding,” Electronics and Communications in Japan, vol. 90, no. 9, pp. 11–18, Sep. 2007. Search in Google Scholar

[11] J.-S. Hong and M. J. Lancaster, Microstrip Filters for RF/Microwave applications. New York: Wiley, 2001. Search in Google Scholar

[12] G. Macchiarella, “Extraction of unloaded Q and coupling matrix from measurements on filters with large losses,” IEEE Microw. Wireless Compon. Lett., vol. 20, no. 6, pp. 307–309, Jun. 2010.10.1109/LMWC.2010.2047455 Search in Google Scholar

[13] R. J. Cameron, C. M. Kudsia, and R. R. Mansour, Microwave Filters for Communication Systems. New York, NY, USA: Wiley, 2007. Search in Google Scholar

Received: 2019-09-13
Published Online: 2019-10-18
Published in Print: 2019-11-26

© 2019 Walter de Gruyter GmbH, Berlin/Boston