2.9 - 8.4 GHz Filter Bank Using Stub-Loaded Multi-Mode Resonators

Yinhua Yao^*, Tongxiu Fan

Microwave Center, No. 36 Research Institute of CETC, Jiaxing, China.

DOI: 10.4236/jemaa.2014.613041                

Abstract

This paper consolidates the activity of design and fabrication of 2.9 - 4.32 GHz, 4.3 - 6.42 GHz, and 6.4 - 8.4 GHz filter bank. Novel compact microstrip bandpass filters with stub-loaded multi-mode resonators are proposed. Simulated results indicate that all the filters exhibit insertion losses less than 1.5 dB with passband ripples of 1 dB and sharp attenuations of above 40 dB in their stopbands. The maximums of input and output VSWRs are 1.742 and 1.734, respectively. Due to fabrication error, the initial measured passbands show frequency shifts and insertion losses in upper passbands deteriorate seriously. After tuning of the filter bank, measured results imply that the input and output VSWRs are found lower than 2.135 and 2.187, and the insertion loss in 1 dB bandwidth is less than 2.52 dB. Filter bank has a sharp skirt and out-of-band rejection levels approaching to 40 dB in all desired stopbands except at the frequencies near 2f_0.

Keywords

Multi-Mode Resonator, 1 dB Bandwidth, Filter Bank

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Lalitha, S., Ram, S. and Kuma, C. Design and Development of 0.5-18 GHz Switch Filter Banks. http://www.technicaljournals.org/PDF/IJCEA-07.pdf
[2]	Konpang, J., Jumneansri, C., Anunvrapong, P. and Wongmethanukroah, J. (2007) A Dual-Mode Wide-Band Bandpass Filter Using the Microstrip Loop Resonator with Tuning Stubs. Proceedings of European Microwave Conference, ICM - Munich International Congress Centre Munich, Germany, 9-12 October 2007, 791-794.
[3]	Singh, K., Ramasubramanian, R. and Pal., S. (2005) Coupled Microstrip Filters: Simple Methodologies for Improved Characteristics. Proceedings of India EESOF User Group Meeting.
[4]	Hong, J.S. and Lancaster, M.J. (2011) Microstrip Filters for RF/Microwave Applications. 2nd Edition, John Wiley & Sons Ltd., Hoboken.
[5]	Zhang, S.B. and Zhu, L. (2011) Compact and High-Selectivity Microstrip Bandpass Filters Using Triple-/Quad-Mode Stub-Loaded Resonators. IEEE Microwave and Wireless Components Letters, 21, 522-524. http://dx.doi.org/10.1109/LMWC.2011.2166252
[6]	Zhu, L., Sun, S. and Menzel, W. (2005) Ultra-Wideband (UWB) Bandpass Filters Using Multiple-Mode Resonator. IEEE Microwave and Wireless Components Letters, 15, 796-798. http://dx.doi.org/10.1109/LMWC.2005.859011
[7]	Liu, J.Q., Song, K.J., Tao, P., Zha, J.H., Fan, Y., et al. (2012) Ultra-Wideband (UWB) Bandpass Filter with Inductance-Loaded Y-Shaped Multiple-Mode Resonator. IEEE International Workshop on Microwave and Millimeter Wave Circuits and System Technology (MMWCST2012), Chengdu, 19-21 September 2012, 94-97.
[8]	Wong, S.W. and Zhu, L. (2007) EBG-Embedded Multiple-Mode Resonator for UWB Bandpass Filter with Improved Upper-Stopband Performance. IEEE Microwave and Wireless Components Letters, 17, 421. http://dx.doi.org/10.1109/LMWC.2007.897788
[9]	Chen, C.P., Oda, J., Kamiji, Y., Anada, T. and Ma, Z.W. (2012) Theoretical/Synthesis Design of Compact UWB Bandpass Filters with Very Sharp Roll-off Characteristics Proceedings of Asia Pacific Microwave Conference (APMC 2012), Kaohsiung, Taiwan, 4-7 December 2012, 112-114.
[10]	Li, R. and Zhu, L. (2007) Compact UWB Bandpass Filter Using Stub-Loaded Multiple-Mode Resonator. IEEE Microwave and Wireless Components Letters, 17, 40-42. http://dx.doi.org/10.1109/LMWC.2006.887251
[11]	Deng, H.W., Zhao, Y.J., Zhang, L., Zhang, X.S. and Gao, S.P. (2010) Compact Quintuple-Mode Stub-Loaded Resonator and UWB Filter. IEEE Microwave and Wireless Components Letters, 20, 438-440. http://dx.doi.org/10.1109/LMWC.2010.2049481
[12]	Xu, J. and Wu, W. (2013) Compact Microstrip Dual-Mode Dual-Band Bandpass Filters Using Stubs Loaded Coupled Line. Progress in Electromagnetics Research C, 41, 137-150. http://dx.doi.org/10.2528/PIERC13052204
[13]	Martin, P. Designing Edge-Coupled Microstrip Bandpass Filters Using in Microwave Office TM. http://www.doc88.com/p-7455947070689.html
[14]	Zhu, L., Wecowski, P.M. and Wu, K. (1999) New Planar Dual-Mode Filter Using Cross-Slotted Patch Resonator for Simultaneous Size and Loss Reduction. IEEE Transactions on Microwave Theory and Techniques, 47, 650-654. http://dx.doi.org/10.1109/22.763171