Expansion method of bandstop for compline bandpass filters
Keywords:input impedance, resonant frequencies, antiresonance frequencies, susceptance slope parameter, bandpass filter, stopband
The article proposes a new method for expanding the stopband of combline bandpass filters (BPF) containing quarter-wave resonators. The filter contains resonators from segments of transmission lines of a quarter-wave length, one end of which is short-circuited. The quarter-wave (λ/4) resonators are oriented in one direction and are parallel to each other without mutual displacement. The disadvantage of such BPF is the many spurious passbands and not wide enough stopband located between the main passband and the first spurious passband. This method is based on the features of the input functions of λ/4 resonators, which appear at different coordinates of connection to these resonators. To obtain a wide stopband, spurious passband associated with higher (spurious) resonant frequencies 3f0, 5f0, 7f0, etc. are eliminated. For this, the resonators are connected to each other at special points located at a certain distance from the short-ends of λ/4 resonators. Using the proposed method, it is possible to suppress a significant number of spurious passbands in combline BPFs with λ/4 resonators, and make the stopband wide enough. In the article, a combline filter with inductive couplings between resonators and between end resonators and load is constructed. However, the proposed method allows us to use the other couplings between resonators. The results of frequency characteristics simulation are presented. The ratio R of the resonant frequency of the first non-suppressed (spurious) passband to the resonant frequency of the main passband increases with an increase in the BPF's order n. For n = 3, 4, 5 the values of R = 11, 13, 15 were obtained, respectively.
Hong J.-S. Microstrip Filters for RF/Microwave Application / J. -S. Hong. - 2nd ed. - New York: Wiley, 2011.
Xu, J.-X. High-Q-factor dual-band bandpass filter and filtering switch using stub-loaded coaxial resonators / J.-X. Xu, X. Y. Zhang, Y. Yang // Proc. of 2019 IEEE MTT-S Int. Wireless Symp., 19-22 May 2019, Guangzhou, China. - IEEE, 2019. - DOI: https://doi.org/10.1109/IEEE-IWS.2019.8803878.
Wang, K. X. A miniaturized filtering power divider with wide stopband / Kai Xu Wang, Hang Wong, Jun Xiang, Xiu Yin Zhang // Proc. of 2014 Int. Symp. on Antennas and Propagation Conf., 2-5 Dec. 2014, Kaohsiung, Taiwan. IEEE, 2015. - DOI: https://doi.org/10.1109/ISANP.2014.7026527.
Захаров А. В. Полосковые полосно-пропускающие фильтры со ступенчатыми резонаторами / А. В. Захаров, М. Е. Ильченко, В. Я. Карнаух, Л. С. Пинчук // Известия вузов. Радиоэлектроника. - 2011. - Т. 54, № 3. - С. 56-63. - DOI: https://doi.org/10.20535/S0021347011030071.
Kuo J.-T. Compact planar quasi-elliptic function filter with inline stepped-impedance resonators / J.-T. Kuo, C.-L. Hsu, E. Shih // IEEE Trans. Microwave Theory Tech. - Aug. 2007. - Vol. 55, No. 8. - P. 1747-1755. - DOI: https://doi.org/10.1109/TMTT.2007.901604.
Matthaei G. L. Microwave Filters, Impedance-Matching Network, and Coupling Structures / G. L. Matthaei, L. Young, E. M. T. Jones. - Norwood, MA: Artech House, 1980.
Lin, T.-W. New miniaturized ring resonator bandpass filter with wide upper stopband / Tsu-Wei Lin, Jen-Tsai Kuo, Shyh-Jong Chung // IEEE MTT-S International Microwave Symposium Digest. - IEEE, 2013. - DOI: http://doi.org/10.1109/MWSYM.2013.6697738.
Feng, W. Balanced filters with wideband common mode suppression using dual-mode ring resonators / W. Feng, W. Che, and Q. Xue // IEEE Trans. Circuits Syst. I, Reg. Papers. - Vol. 62, No. 6. - P. 1499-1507. - Jun. 2015. - DOI: https://doi.org/10.1109/TCSI.2015.2423752.
G'omez-Garc'ia, R. Multi-stub-loaded differential-mode planar multiband bandpass filters / Roberto G'omez-Garc'ia, Ra'ul Loeches-S'anchez, Dimitra Psychogiou, Dimitrios Peroulis // IEEE Trans. Circuits Syst. II, Express Briefs. - Vol. 65, No. 3. - P. 271-275. - 2018. DOI: https://doi.org/10.1109/TCSII.2017.2688336.
Zhang X. Y. Harmonic-suppressed bandpass filter based on discriminating coupling / X. Y. Zhang, Q. Xue // IEEE Microwave Wireless Compon. Lett. - Nov. 2009. - Vol. 19, No. 11. - P. 695-697. - DOI: https://doi.org/10.1109/LMWC.2009.2032002.
Li Y. C. Bandpass filter using discriminating coupling for extended out-of-band suppression / Y. C. Li, X. Y. Zhang, Q. Xue // IEEE Microwave Wireless Compon. Lett. - Jul. 2010. - Vol. 20, No. 7. - P. 369-371. - DOI: https://doi.org/10.1109/LMWC.2010.2049425.
Lin S.-C. Extended-stopband bandpass filter using both half- and quarter-wavelength resonators / S.-C. Lin, Y.-S. Lin, C. H. Chen // IEEE Microwave Wireless Compon. Lett. - Jan. 2006. - Vol. 16, No. 1. - P. 43-45. - DOI: https://doi.org/10.1109/LMWC.2005.860014.
Zakharov A. V. Features of the coupling coefficients of planar stepped-impedance resonators at higher resonance frequencies and application of such resonators for suppression of spurious passbands / A. V. Zakharov, M. E. Il'chenko, V. N. Korpach // J. Commun. Technol. Electronics. - 2014. - Vol. 59, No. 6. - P. 550-556. - DOI: https://doi.org/10.1134/S1064226914060217.
Захаров А. В. Увеличение полосы заграждения планарных полосно-пропускающих фильтров / А. В. Захаров // Радиотехника и электроника. - 2012. - Т. 57, № 1. - С. 102-108.
Hong J.-S. (2011) Microstrip Filters for RF/Microwave Application. 2nd ed. New York: Wiley.
Xu J., Zhang X.Y. and Yang Y. (2019) High-Q-Factor Dual-Band Bandpass Filter and Filtering Switch Using Stub-Loaded Coaxial Resonators. 2019 IEEE MTT-S International Wireless Symposium (IWS). DOI: 10.1109/ieee-iws.2019.8803878
Wang K.X., Wong H., Xiang J. and Zhang X.Y. (2014) A miniaturized filtering power divider with wide stopband. 2014 International Symposium on Antennas and Propagation Conference Proceedings, . DOI: 10.1109/isanp.2014.7026527
Zakharov A.V., Ilchenko M.Y., Karnauh V.Y. and Pinchuk L.S. (2011) Stripline bandpass filters with step-impedance resonators. Radioelectronics and Communications Systems, Vol. 54, Iss. 3, pp. 163-169. DOI: 10.3103/s0735272711030071
Kuo J., Hsu C. and Shih E. (2007) Compact Planar Quasi-Elliptic Function Filter With Inline Stepped-Impedance Resonators. IEEE Transactions on Microwave Theory and Techniques, Vol. 55, Iss. 8, pp. 1747-1755. DOI: 10.1109/tmtt.2007.901604
G. L. Matthaei, L. Young, E. M. T. Jones (1980) Microwave Filters, Impedance-Matching Network, and Coupling Structures. Norwood, MA: Artech House.
Lin T., Kuo J. and Chung S. (2013) New miniaturized ring resonator bandpass filter with wide upper stopband. 2013 IEEE MTT-S International Microwave Symposium Digest (MTT), . DOI: 10.1109/mwsym.2013.6697738
Lin T., Kuo J. and Chung S. (2013) New miniaturized ring resonator bandpass filter with wide upper stopband. 2013 IEEE MTT-S International Microwave Symposium Digest (MTT). DOI: 10.1109/mwsym.2013.6697738
Gomez-Garcia R., Loeches-Sanchez R., Psychogiou D. and Peroulis D. (2018) Multi-Stub-Loaded Differential-Mode Planar Multiband Bandpass Filters. IEEE Transactions on Circuits and Systems II: Express Briefs, Vol. 65, Iss. 3, pp. 271-275. DOI: 10.1109/tcsii.2017.2688336
Zhang X.Y. and Xue Q. (2009) Harmonic-Suppressed Bandpass Filter Based on Discriminating Coupling. IEEE Microwave and Wireless Components Letters, Vol. 19, Iss. 11, pp. 695-697. DOI: 10.1109/lmwc.2009.2032002
Li Y.C., Zhang X.Y. and Xue Q. (2010) Bandpass Filter Using Discriminating Coupling for Extended Out-of-Band Suppression. IEEE Microwave and Wireless Components Letters, Vol. 20, Iss. 7, pp. 369-371. DOI: 10.1109/lmwc.2010.2049425
Lin S., and Chen C.H. (2006) Extended-stopband bandpass filter using both half- and quarter-wavelength resonators. IEEE Microwave and Wireless Components Letters, Vol. 16, Iss. 1, pp. 43-45. DOI: 10.1109/lmwc.2005.860014
Zakharov A.V., Il’chenko M.E. and Korpach V.N. (2014) Features of the coupling coefficients of planar stepped-impedance resonators at higher resonance frequencies and application of such resonators for suppression of spurious passbands. Journal of Communications Technology and Electronics, Vol. 59, Iss. 6, pp. 550-556. DOI: 10.1134/s1064226914060217
Zakharov A.V. (2012) Expanding the rejection band of planar bandpass filters. Journal of Communications Technology and Electronics, Vol. 57, Iss. 1, pp. 95-100. DOI: 10.1134/s1064226911090105
How to Cite
Authors who publish with this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in this journal.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).