Abstract
An analytical approach for the synthesis of narrow-band lossy filters with arbitrary transmission zeros is proposed in this paper. The scattering parameters are deduced from filtering polynomials once the transmission zeros are assigned. The formulas defining the transformation from scattering matrix to admittance matrix can be used by reconstructing the non-paraconjugate transmission zeros as paraconjugate. A canonical \(N + 2\) transversal or \(N \times N\) coupling matrix is then identified using partial fraction expansion of the normalized admittance functions. An increased order of the final network (with respect to the order of the characteristic polynomials) is required for obtaining this result, provided there are non-paraconjugate transmission zeros. Because of its versatility, the proposed approach can also be employed for lossless networks that have a transfer function with symmetrical transmission zeros. Two typical examples are presented to validate the proposed technique.





Similar content being viewed by others
References
H.C. Bell, The coupling matrix in low-pass prototype filters. IEEE Microw. Mag. 8(2), 70–76 (2007)
R. Cameron, C. Kudsia, R. Mansour, Microwave Filters for Communication Systems (Wiley, Hoboken, 2007)
R. Cameron, General coupling matrix synthesis methods for Chebyshev filtering functions. IEEE Trans. Microw. Theory Tech. 47(4), 433–442 (1999)
A. Guyette, I. Hunter, R. Pollard, The design of microwave bandpass filters using resonators with nonuniform. IEEE Trans. Microw. Theory Tech. 54(11), 3914–3922 (2006)
G. Li, Fast synthesis of cross-coupled resonator filters using hybrid optimization algorithm. Int. J. RF Microw. Comput. Aided Eng. 25(5), 445–452 (2015)
V. Miraftab, M. Yu, Advanced coupling matrix and admittance function synthesis techniques for dissipative microwave filters. IEEE Trans. Microw. Theory Tech. 57(10), 2429–2438 (2009)
V. Miraftab, M. Yu, Generalized lossy microwave filter coupling matrix synthesis and design using mixed technologies. IEEE Trans. Microw. Theory Tech. 56(12), 3016–3027 (2008)
D. Navarro-Tapia, E.Otero Sorolla et al., Coupling matrix synthesis of dissipative microwave filters. IET Microw. Antennas Propag. 5(8), 895–900 (2011)
M. Oldoni, G. Macchiarella, G. Gentili et al., A new approach to the synthesis of microwave lossy filters. IEEE Trans. Microw. Theory Tech. 58(5), 1222–1229 (2010)
L. Szydlowski, A. Lamecki, M. Mrozowski, Synthesis of coupled-lossy resonator filters. IEEE Microw. Wirel. Compon. Lett. 20(7), 366–368 (2010)
F. Xiao, Direct synthesis of general Chebyshev bandpass filters in the bandpass domain. IEEE Trans. Circuit Syst. 61(8), 2411–2421 (2014)
Q. Zhang, C. Caloz, Alternative construction of the coupling matrix of filters with non-paraconjugate transmission zeros. IEEE Microw. Wirel. Compon. Lett. 23(10), 509–511 (2013)
Y. Zhao, G. Wang, Multi-objective optimisation technique for coupling matrix synthesis of lossy filters. IET Microw. Antennas Propag. 7(11), 926–933 (2013)
Acknowledgements
The author would like to thank Dr. Diego Navarro-Tapia for useful discussions concerning the coupling matrix. This study was supported by the National High-Tech Research Development Plan (863 Plan) (2015AA016201).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Li, G. Analytical Coupling Matrix Synthesis for Lossy Filters with Arbitrary Transmission Zeros. Circuits Syst Signal Process 36, 4729–4740 (2017). https://doi.org/10.1007/s00034-017-0521-x
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00034-017-0521-x