A novel dual-band substrate integrated waveguide (SIW) filter with multiple transmission zeros and good out-of-band rejection performance is presented in this paper. For this purpose, an orthogonal input/output (I/O) feeding structure directly connected to the substrate integrated waveguide (SIW) cavity is designed to split the resonant frequencies of the degenerate pair of mode. The filter can be modeled with a multi-path circuit formed by three modes (TE101, TE201 and TE102 modes) and weak cross coupling between I/O ports, thereby producing three transmission zeros which make the dual-band high selectivity. The offset of the input/output ports shifts the second transmission zero to a lower frequency from the upper passband. Several filter prototypes are designed and fabricated for demonstration, and the measured results validate the new structure for high selectivity applications.
2. Sekar, V. and K. Entesari, "A novel compact dual-band half-mode substrate integrated waveguide bandpass filter," IEEE MTT-S International Microwave Symposium Digest. IEEE MTT-S International Microwave Symposium, 1-4, 2011.
3. Sekar, V. and K. Entesari, "Miniaturized half-mode substrate integrated waveguide bandpass filters using cross-shaped fractals," 2011 IEEE 12th Annual. IEEE Wireless and Microwave Technology Conference (WAMICON), 1-5, 2011.
4. Zhang, X., C. Ma, and F. Wang, "Design of compact dual-passband LTCC filter exploiting stacked QMSIW and EMSIW," Electronics Letters, Vol. 51, No. 12, 912-914, 2015.
5. Chu, P., et al., "A planar bandpass filter implemented with a hybrid structure of substrate integrated waveguide and coplanar waveguide," IEEE Transactions on Microwave Theory & Techniques, Vol. 62, No. 2, 266-274, 2014.
6. Chen, R. S., et al., "Wideband bandpass filter using u-slotted substrate integrated waveguide (SIW) cavities," IEEE Microwave & Wireless Components Letters, Vol. 25, No. 1, 1-3, 2015.
7. Chen, J., et al., "Design of dual-band substrate integrated waveguide filter using frequency transformation method," 2010 International Conference on Microwave and Millimeter Wave Technology (ICMMT), 1286-1289, 2010.
8. Lenoir, P., et al., "Synthesis and design of asymmetrical dual-band bandpass filters based on equivalent network simplificatio," IEEE Transactions on Microwave Theory & Techniques, Vol. 54, No. 7, 3090-3097, 2006.
9. Li, D., et al., "A novel miniaturized and dual-band filter of substrate integrated waveguide based on SCMRC," 2013 Cross Strait Quad-Regional Radio Science and Wireless Technology Conference (CSQRWC), 82-85, 2013.
10. Rezaee, M. and A. R. Attari, "A novel dual mode dual band SIW filter," 2014 44th European IEEE Microwave Conference (EuMC), 853-856, 2014.
11. Turgaliev, V., et al., "A novel dual-bandpass microwave filter using espilon-near-zero metamaterials," 2013 7th International Congress on IEEE Advanced Electromagnetic Materials in Microwaves and Optics (Metamaterials), 136-138, 2013.
12. Wang, Z. D., et al., "Design of dual-band bandpass SIW filter with DGS," 2012 International Conference on Microwave and Millimeter Wave Technology (ICMMT), 1-3, 2012.
13. Senior, D. E., et al., "Single and dual band bandpass filters using complementary split ring resonator loaded half mode substrate integrated waveguide," 2010 IEEE Antennas and Propagation Society International Symposium (APSURSI), 1-4, 2010.
14. Dong, Y. and T. Itoh, "Miniaturized dual-band substrate integrated waveguide filters using complementary split-ring resonators," 2011 IEEE MTT-S International IEEE Microwave Symposium Digest (MTT), 1-4, 2011.
15. Salehi, M., J. Bornemann, and E. Mehrshahi, "Compact folded substrate integrated waveguide filter with non-resonating nodes for high-selectivity bandpass applications," 2013 European IEEE Microwave Conference (EuMC), 155-158, 2013.