This paper proposes a microwave filter post-production tuning based on an optimization process which finds the vector of deviations of tuning elements that should be applied to tune the filter. To build the system, the coarse set of scattering parameters is collected in such a way that every tuning element is detuned while other elements remain in their proper positions. In the concept, it is assumed that the relation between the positions of tuning elements and filter scattering characteristics can be modelled by the sum of one argument polynomial functions. Each polynomial function depends on the value of only one tuning element. Therefore, the measured filter characteristics can be linearly decomposed to characteristics from the collected coarse set and corresponding tuning element deviations can be found. This is done by way of optimization process. The presented numerical and physical experiments on the 7th order cross-coupled, bandpass filter have verified our approach.
Jerzy Julian Michalski,
"Filter Tuning Based on Linear Decomposition of Scattering Characteristics," Progress In Electromagnetics Research,
Vol. 135, 451-464, 2013. doi:10.2528/PIER12112603
1. Dunsmore, , J., "Tuning band pass filters in the time domain,"," IEEE MTT-S Int. Microwave Symp. Digest, 1351-1354, 1999.
2. Thal, , H. L., , "Computer-aided filter alignment and diagnosis," IEEE Trans. on Microwave Theory and Tech., Vol. 26, No. 12, 958-963, Dec. 1978.. doi:10.1109/TMTT.1978.1129528
3. Miraftab, , V. , R. R. Mansour, and , "Computer-aided tuning of microwave filters using fuzzy logic," IEEE Trans. on Microwave Theory and Tech., Vol. 50, 2781-2788, Dec. 2002. doi:10.1109/TMTT.2002.805291
4. Michalski, , J. J., "Artificial neural networks approach in microwave filter tuning," Progress In Electromagnetics Research M, Vol. 13, 173-188, 2010. doi:10.2528/PIERM10053105
5. Michalski, , J. J., "Inverse modeling in application for sequential filter tuning," Progress In Electromagnetics Research,, Vol. 115, 113-129, 2011.
6. Kacmajor, T., J. J. Michalski, and , "Neuro-fuzzy approach in microwave filter tuning," IEEE MTT-S Int. Microwave Symp. Digest, , 1-4, 2011.
7. Michalski, J. J., "On linear mapping of filter characteristic to position of tuning elements in filter tuning algorithm," Progress In Electromagnetics Research, Vol. 123, 279-298, 2012. doi:10.2528/PIER11101009
8. Kacmajor, T. and J. J. Michalski, "Approximation of filter characteristic to tuning element positions using coarse set," Proc. 19th Int. Conf. Microwave, Radar and Wireless Communications, Vol. 2, 684-687, 2012..
9. Atia, , A. E. , A. E. Williams, and R. Newcomb, "Narrow-band multiple-coupled cavity synthesis," IEEE Trans. on Circuits Syst.,, Vol. 21, No. 5, 649-655, Sep. 1974. doi:10.1109/TCS.1974.1083913
10. Atia, , A. E., A. E. Williams, and , "Narrow-bandpass waveguide filters," IEEE Trans. on Microwave Theory and Tech., Vol. 20, No. 4, 258-265, 1972. 1972. doi:10.1109/TMTT.1972.1127732
11. Cameron, R. J., , C. M. Kudsia, and R. R. Mansour, Microwave Filters for Communication Systems, J. Wiley & Sons, , 2007..
12. Wang, R., , J. Xu, C. L. Wei, M.-Y. Wang, and X.-C. Zhang, "Improved extraction of coupling matrix and unloaded Q from S-parameters of lossy resonator filters," Progress In Electromagnetics Research, Vol. 120, 67-81, 2011..
13. Wang, , R. , J. Xu, and , "Extracting coupling matrix and unloaded Q from scattering parameters of lossy filters," Progress In Electromagnetics Research, Vol. 115, 303-315, 2011..
14. Xiao, , K., , L. F. Ye, F. Zhao, S.-L. Chai, and J. L.-W. Li, "Coupling matrix decomposition in designs and applications of microwave filters," Progress In Electromagnetics Research, Vol. 117, 409-423, 2011.
15. Gulgowski, , J. , J. J. Michalski, and , "The analytic extraction of the complex-valued coupling matrix and its application in the microwave filter modelling," Progress In Electromagnetics Research, Vol. 130, 131-151, 2012.
16. Corrales, , E., Corrales, E., P. de Paco, and O. Menendez, Direct coupling ma-, "Direct coupling matrix synthesis of band-stop filters," Progress In Electromagnetics Research Letters, Vol. 27, 85-91, 2011. doi:10.2528/PIERL11091512
17. Michalski, , J. J., , J. Gulgowski, T. Kacmajor, and M. Piatek, "Coupling matrix synthesis by optimization with cost function Coupling matrix synthesis by optimization with cost function," PIERS Proceedings,, 1351-1354, , Aug. 2012.
18. Cameron, , R. J., , "Cameron, R. J., Advanced coupling matrix synthesis techniques for microwave filters," IEEE Trans. on Microwave Theory and Tech., Vol. 51, No. 1, 1-10, Jan. 2003. doi:10.1109/TMTT.2002.806937
19. Lagarias, J. C., J. A. Reeds, M. H. Wright, and P. E. Wright, "Convergence properties of the Nelder-Mead simplex method in low dimensions," SIAM Journal of Optimization, Vol. 9, No. 1, 112-147, 1998. doi:10.1137/S1052623496303470