This paper describes the synthesis of a bandpass filter to achieve high selectivity and rejection properties using a new class of filter functions called chained-elliptic function filters. Chained-elliptic filters have higher selectivity than Chebyshev function filters and have the property of sensitivity to manufacturing tolerance reduction in chained-function filters. The proposed design has high selectivity and reduced sensitivity, enabling easier and faster filter fabrication. The characteristic polynomials of chained-elliptic function filters are derived through chaining elliptic filtering function and extracted to form a coupling matrix of the bandpass filter. The novel transfer polynomials are given in detail, and a thorough investigation of the filter characteristics is performed. A theoretical comparison with Chebyshev and elliptic filters of the same order is performed to ascertain the demonstrated advantages of this proposed filter class. A high frequency narrow-band fourth-order chained-elliptic function waveguide filter centred at 28 GHz with a fractional bandwidth of 1.61% is fabricated to validate the proposed design concept. A good match among the measured, simulated and ideal filter responses is shown where the overall responses between measurement and simulation have a difference of approximately 2% which is within the acceptable limit. The chained-elliptic function concept will be useful in designing low-cost high-performance microwave filters with various fabrication technologies for millimetre-wave applications.
Guan Shen Ng,
Peng Wen Wong,
"Synthesis of Chained-Elliptic Function Waveguide Bandpass Filter with High Rejection," Progress In Electromagnetics Research C,
Vol. 99, 61-75, 2020. doi:10.2528/PIERC19112002
1. Chrisostomidis, C. E. and S. Lucyszyn, "On the theory of chained-function filters," IEEE Transactions on Microwave Theory and Techniques, Vol. 53, No. 10, 3142-3151, Oct. 2005. doi:10.1109/TMTT.2005.855358
2. Guglielmi, M. and G. Connor, "Chained function filters," IEEE Microw. Guided Wave Lett., Vol. 7, No. 12, 390-392, Dec. 1997. doi:10.1109/75.645181
3. Chrisostomidis, C. E. and S. Lucyszyn, "Seed function combination selection for chained function filters," IET Microwaves, Antennas and Propagation, Vol. 4, 799-807, Jun. 2010. doi:10.1049/iet-map.2009.0508
4. Chrisostomidis, C. E., M. Guglielmi, P. Young, and S. Lucyszyn, "Application of chained functions to low-cost microwave band-pass filters using standard PCB etching techniques," 2000 30th European Microwave Conference, Oct. 2000.
5. Lim, Y. P., Y. L. Toh, S. Cheab, G. S. Ng, and P. W. Wong, "Chained-function waveguide filter for 5G and beyond," TENCON 2018 --- 2018 IEEE Region 10 Conference, 2018.
6. Lim, Y. P., Y. L. Toh, S. Cheab, S. Lucyszyn, and P. W. Wong, "Coupling matrix synthesis and design of a chained-function waveguide filter," 2018 Asia-Pacific Microwave Conference (APMC), 2018.
7. Perenic, G., N. Stamenkovic, N. Stojanovic, and N. Denic, "Chained-function filter synthesis based on the modified Jacobi polynomials," Radioengineering, Vol. 27, No. 4, 1112-1118, 2018. doi:10.13164/re.2018.1112
8. Stojanovic, N., N. Stamenkovic, and I. Krstic, "Chained-function filter synthesis based on the Legendre polynomials," Circuits, Systems, and Signal Processing, Vol. 37, No. 5, 2001-2020, Aug. 2017. doi:10.1007/s00034-017-0651-1
9. Zverev, A. I., Handbook of Filter Synthesis, Wiley, New York, 1967.
10. Cameron, R. J., C. M. Kudsia, and R. R. Mansour, Microwave Filters for Communication Systems: Fundamentals, Design, and Applications, 2nd Ed., Wiley, New York, Apr. 2018. doi:10.1002/9781119292371
11. Hunter, I., Theory and Design of Microwave Filters, (IET Electromagnetic Waves Series), 370, The Institution of Engineering and Technology, London, United Kingdom, 2006.
12. Xu, J., "Compact quasi-elliptic response wideband bandpass filter with four transmission zeros," IEEE Microwave and Wireless Components Letters, Vol. 25, No. 3, 169-171, 2015. doi:10.1109/LMWC.2015.2390571
14. Chen, C.-J., "A coupled-line coupling structure for the design of quasi-elliptic bandpass filters," IEEE Transactions on Microwave Theory and Techniques, Vol. 66, No. 4, 1921-1925, 2018. doi:10.1109/TMTT.2017.2783378
15. Zhang, F., J. Li, P. Zhao, G. Huang, and J. Xu, "A wideband microstrip elliptic bandpass filter with flexibly tunable bandwidth," 2018 International Conference on Microwave and Millimeter Wave Technology (ICMMT), 2018.
16. Dimopoulos, H. G., "Optimal use of some classical approximations in filter design," IEEE Transactions on Circuits and Systems II: Express Briefs, Vol. 54, No. 9, 780-784, 2007. doi:10.1109/TCSII.2007.900345
17. Wang, L. and L. Jin, "A quasi-elliptic microstrip bandpass filter using modified anti-parallel coupled-line," Progress In Electromagnetics Research, Vol. 138, 245-253, 2013.
18. Kuo, J.-T., S.-C. Tang, and S.-H. Lin, "Quasi-elliptic function bandpass filter with upper stopband extension and high rejection level using cross-coupled stepped-impedance resonators ," Progress In Electromagnetics Research, Vol. 114, 395-405, 2011. doi:10.2528/PIER11011002
19. Poularikas, A., The Handbook of Formulas and Tables for Signal Processing, CRC Press, Boca Raton, Fla., 1999.
20. Chisostomidis, C. E., "Chained function filters --- Theory and applications,", Ph.D. dissertation, Univ. Surrey, Surrey, U.K., 2003.
21. Cameron, R. J., "Advanced coupling matrix synthesis techniques for microwave filters," IEEE Transactions on Microwave Theory and Techniques, Vol. 51, No. 1, 1-10, Jan. 2003. doi:10.1109/TMTT.2002.806937
22. Cameron, R., "General coupling matrix synthesis methods for Chebyshev filtering functions," IEEE Transactions on Microwave Theory and Techniques, Vol. 47, No. 4, 433-442, Apr. 1999. doi:10.1109/22.754877
23. Kocbach, J. and K. Folgero, "Design procedure for waveguide filters with cross-couplings," IEEE MTT-S Int Microwave Symp. Dig., Vol. 3, 1449-1452, Jun. 2002.
24. Huang, Q. and Z. Wu, "A compact six-order folded-waveguide resonator filter," 2018 IEEE MTT-S International Wireless Symposium (IWS), 2018.
25. Kojima, H., M. Nakahori, K. Matsutani, K. Kuroda, and K. Onaka, "A compact 28GHz bandpass filter using quartz folded waveguide," 2018 IEEE MTT-S International Microwave Symposium (IMS), 2018.
26. Matsutani, K., et al., "Miniaturized quartz waveguide filter using double-folded structure," 2019 IEEE MTT-S International Microwave Symposium (IMS), 2019.