In this paper, a quadri-folded substrate integrated waveguide (QFSIW) resonant cavity is proposed and investigated for the first time, which is able to reduce the circuit size by 89% compared with the conventional substrate integrated waveguide (SIW) resonant cavity. It has a two-layer configuration and a C-type coupling slot etched on the middle conductor layer. As an example, such a miniaturized resonant cavity is employed in the design of a four-order S-band SIW bandpass filter with the Chebyshev response. Negative couplings are used between two adjacent SIW resonant cavities, which don't influence the whole transmission characteristic of the filter. Experimental results are in good agreement with those from simulations.
1. Uchimura, H., T. Takenoshita, and M. Fuji, "Development of `a laminated waveguide'," IEEE Transactions on Microwave Theory and Techniques, Vol. 46, No. 9, 2438-2443, Sep. 1998. doi:10.1109/22.739232
2. Hirokawa, J. and M. Ando, "Efficiency of 76-GHz post-wall waveguide-fed parallel-plate slot arrays," IEEE Trans. Antennas Propag., Vol. 48, No. 11, 1742-1745, Nov. 2000. doi:10.1109/8.900232
3. Hong, W., K. Wu, H. J. Tang, J. X. Chen, P. Chen, Y. J. Cheng, and J. F. Xu, "SIW-liked guided wave structure and application," IEICE Transaction on Electronic, Vol. E92.C, No. 9, 1111-1123, Sep. 2009. doi:10.1587/transele.E92.C.1111
4. Cheng, Y. J., W. Hong, and K. Wu, "Broadband self-compensating phase shifter combining delay line and equal-length unequal-width phaser," IEEE Transactions on Microwave Theory and Techniques, Vol. 58, No. 1, 203-210, Jan. 2010. doi:10.1109/TMTT.2009.2035942
5. Cheng, Y. J., W. Hong, K. Wu, and Y. Fan, "Millimeter-wave substrate integrated waveguide long slot leaky-wave antennas and two-dimensional multibeam applications," IEEE Trans. Antennas Propag., Vol. 59, No. 1, 40-47, Jan. 2011. doi:10.1109/TAP.2010.2090471
6. Cheng, Y. J., W. Hong, K. Wu, and Y. Fan, "A hybrid guided-wave structure of half mode substrate integrated waveguide and conductor-backed slotline and its application in directional couplers ," IEEE Microw. Wireless Compon. Lett., Vol. 21, No. 2, 65-67, Feb. 2011.
7. Hong, J. S., "Compact folded-waveguide resonators and filters," IEE Proceedings Microwaves, Antennas and Propagation, Vol. 153, 325-329, 2006. doi:10.1049/ip-map:20050047
8. Huang, T. Y., T. M. Shen, and B. J. Chen, "Design of miniaturized vertically stacked SIW filters in LTCC," European Microwave Conference, 413-416, 2009.
9. Wang, R., X. L. Zhou, and L. S. Wu, "A folded substrate integrated waveguide cavity filter using novel negative coupling," Microwave and Optical Technology Letters, Vol. 51, No. 3, 866-871, 2009. doi:10.1002/mop.24181
10. Wang, R., L. S. Wu, and X. L. Zhou, "Compact folded substrate integrated waveguide cavities and bandpass filter," Progress In Electromagnetics Research, Vol. 84, 135-147, 2008. doi:10.2528/PIER08071501
11. Zhang, R. Q., Z. G. Wang, B. Yan, and R. M. Xu, "FSIW cavity filter and derivative FSIW cavity and its filters with LTCC technology ," Asia-Pacific Microwave Conference, 1360-1363, 2009. doi:10.1109/APMC.2009.5384485
12. Che, W. Q., D. P. Wang, L. Xu, and C. X. Li, "Investigation on quality factor of substrate-integrated waveguide resonance cavity," Microwave and Optical Technology Letters, Vol. 49, No. 8, 2007-2010, Aug. 2007. doi:10.1002/mop.22592
13. Chien, H. Y., T. M. Shen, T. Y. Huang, W. H. Wang, and R. B. Wu, "Miniaturized bandpass filters with double-folded substrate integrated waveguide resonators in LTCC ," IEEE Transactions on Microwave Theory and Techniques, Vol. 57, No. 7, 1774-1782, 2009. doi:10.1109/TMTT.2009.2022591
14. Hong, W. and K. Gong, "Miniaturization of substrate integrated bandpass filters," Asia-Pacific Microwave Conference Proceedings (APMC), 247-250, 2010.
15. Gong, K., W. Hong, H. J. Tang, and J. X. Chen, C-band bandpass filter based on half mode substrate integrated waveguide (HMSIW) cavities, Asia-Pacific Microwave Conference, 7-10, Dec. 2009.
16. Gong, K., W. Hong, J. Chen, H. Tang, D. Hou, and Y. Zhang, "Novel compact bandpass filter based on folded half mode substrate integrated waveguide cavities ," Global Symposium on Millimeter Waves, 14-16, Incheon, Apr. 2010.
17. Hong, J. S. and M. J. Lancaster, Microstrip Filters for RF/Microwave Applications, Chapter 8, 235-271, Wiley, New York, 2001.