High selectivity Microwave Bandpass Filter with a wide Upper Stopband
DOI:
https://doi.org/10.22385/jctecs.v29i0.307Keywords:
Microstrip technology, microwave filters, bandpass filters, high selectivity filters, wide out-of-band rejectionAbstract
This paper describes a highly selective microwave bandpass filters based on microstrip integrated technology. The filter initially proposed consists of electromagnetically coupled C-shaped open-ring resonators whose feedlines are loaded with inductive spiral shaped open-circuited stubs that are strategically located along the feedlines in order to introduce transmission zeros in the filter’s stopband response. It is shown that the overall response and selectivity of this filter can be significantly enhanced by interdigitally coupling the resonators with the feedline. The resulting filter exhibits highly sharp roll-off skirts with a passband insertion-loss of 1.4 and return-loss of greater than 15 dB. The out-of-band rejection level of the filter is better than 20 dB between 3.7-9.4 GHz. Simulation results show that the center frequency of this type of filter can be adjusted from 3.3 to 3.8 GHz by carefully modifying the structure’s dimensions. The proposed coupling scheme allows to control the filter’s 3 dB fractional bandwidth, and results show the fractional bandwidth of the filter can be adjusted between 5.52 to 17.7% with negligible effect on the stopband characteristics. The proposed filter is suitable for applications in high interference environments and cognitive radio systems.Downloads
References
REFERENCES
C.-W. Tang and Y.-K. Hsu, "A microstrip bandpass filter with ultra-wide stopband," IEEE Transactions on microwave theory and techniques, vol. 56, no. 6, pp. 1468-1472, 2008.
T. Lopetegi et al., "Microstrip" wiggly-line" bandpass filters with multispurious rejection," IEEE Microwave and Wireless Components Letters, vol. 14, no. 11, pp. 531-533, 2004.
C.-F. Chen, T.-Y. Huang, and R.-B. Wu, "Design of microstrip bandpass filters with multiorder spurious-mode suppression," IEEE transactions on microwave theory and techniques, vol. 53, no. 12, pp. 3788-3793, 2005.
X. Luo, H. Qian, J.-G. Ma, and K. S. Yeo, "A compact wide stopband microstrip bandpass filter using quarter-wavelength shorted coupled-lines," in 2010 Asia-Pacific Microwave Conference, 2010, pp. 1142-1145: IEEE.
A. Abbaspour-Tamijani, L. Dussopt, and G. M. Rebeiz, "Miniature and tunable filters using MEMS capacitors," IEEE Transactions on Microwave Theory and Techniques, vol. 51, no. 7, pp. 1878-1885, 2003.
L. H. Hsieh and K. Chang, "Simple analysis of the frequency modes for microstrip ring resonators of any general shape and correction of an error in the literature," Microwave and optical technology letters, vol. 38, no. 3, pp. 209-213, 2003.
P.-L. Chi, T. Yang, and T.-Y. Tsai, "A fully tunable two-pole bandpass filter," IEEE Microwave and Wireless Components Letters, vol. 25, no. 5, pp. 292-294, 2015.
X. Y. Zhang and Q. Xue, "High-selectivity tunable bandpass filters with harmonic suppression," IEEE Transactions on Microwave Theory and Techniques, vol. 58, no. 4, pp. 964-969, 2010.
J.-X. Chen, Y. Ma, J. Cai, L.-H. Zhou, Z.-H. Bao, and W. Che, "Novel frequency-agile bandpass filter with wide tuning range and spurious suppression," IEEE Transactions on Industrial Electronics, vol. 62, no. 10, pp. 6428-6435, 2015.
L. Gao and G. M. Rebeiz, "A 0.97–1.53-GHz Tunable Four-Pole Bandpass Filter With Four Transmission Zeroes," IEEE Microwave and Wireless Components Letters, vol. 29, no. 3, pp. 195-197, 2019.
K. Song, W. Chen, S. R. Patience, Y. Chen, A. M. Iman, and Y. Fan, "Compact Wide-Frequency Tunable Filter With Switchable Bandpass and Bandstop Frequency Response," IEEE Access, vol. 7, pp. 47503-47508, 2019.
Downloads
Published
Issue
Section
License
The journal is currently an open access journal.
The articles receive both rigorous peer-review and expedited online publication.
The journal encourages young researchers to submit their unpublished papers.
The authors retain their article’s copyright.
The authors retain publishing rights without restrictions.
Thus, authors may use their own articles for the following non-commercial purposes without asking our permission (and subject only to acknowledging first publication in Journal of Communications Technology, Electronics and Computer Science and giving a full reference or web link, as appropriate).
Authors cannot submit a manuscript for publication to other journals simultaneously. It is a waste of valuable resources because editors and referees spent a great deal of time processing submitted manuscripts. It is also unethical to republish similar research articles (text/figures/tables) again because journals have limited page space and it most likely violates copyrights which have already been transferred to the first journal. Therefore, all journals require a signed author's copyright transfer agreement stating the originality of the research work submitted through a manuscript. As stated above that authors should submit original, new and unpublished research work to the journal. The ethical issues such as plagiarism, fraudulent and duplicate publication, violation of copyrights, authorship and conflict of interest are serious issues concerning ethical integrity when submitting a manuscript to a journal for publication.
The contents of papers are the sole responsibility of the authors, and publication shall not imply the concurrence of the Editors or Publisher.