In this letter, we present a diplexer implemented on a substrate integrated waveguide (SIW) with stepped impedance complementary S-shaped resonators (CSSRs). The variable frequency response of the stepped impedance concept adjoining SIW technology leads to improved device performance in terms of matching and isolation. Simulated and measured results show input matching, |S11|, better than -15 dB and output isolation, |S32|, below -30 dB for the frequency range 1-4 GHz. Furthermore, CSSRs offer a degree of freedom to design fundamental and higher order frequencies by selectively tuning the geometrical parameters. This simple yet effective approach eliminates the complexity to design diplexers based on complementary split ring resonator (CSRRs).
Vijay K. Devabhaktuni,
"SIW Diplexer Loaded with Complementary Stepped Impedance S-Shaped Resonators," Progress In Electromagnetics Research Letters,
Vol. 48, 117-121, 2014. doi:10.2528/PIERL14072702
1. Matthaei, G. L. and E. G. Cristal, "Multiplexer channel-separating using interdigital and parallelcoupled filters," IEEE Trans. Microw. Theory Tech., Vol. 13, No. 3, 328-334, May 1965. doi:10.1109/TMTT.1965.1125997
2. Dong, Y. and T. Itoh, "Substrate integrated waveguide loaded by complementary split-ring resonators for miniaturized diplexer design," IEEE Microw. Wireless Compon. Lett., Vol. 21, No. 1, 10-12, Jan. 2011. doi:10.1109/LMWC.2010.2091263
3. Liu, H., W. Xu, Z. Zhang, and X. Guan, "Compact diplexer using slotline stepped impedance resonators," IEEE Microw. Wireless Compon. Lett., Vol. 23, No. 2, 75-77, Feb. 2013. doi:10.1109/LMWC.2013.2238912
4. Cheng, F., X. Lin, K. Song, Y. Jiang, and Y. Fan, "Compact diplexer with high isolation using the dual-mode substrate integrated waveguide resonator," IEEE Microw. Wireless Compon. Lett., Vol. 23, No. 9, 459-461, Sep. 2013. doi:10.1109/LMWC.2013.2274036
5. Palma, L., F. Bilotti, A. Toscano, and L. Vegni, "Design of a waveguide diplexer based on connected bi-omega particles," IEEE Microw. Wireless Compon. Lett., Vol. 22, No. 3, 126-128, Mar. 2012. doi:10.1109/LMWC.2012.2186560
6. Zhang, Q. L., W. Y. Yin, S. He, and L. S. Wu, "Compact substrate integrated waveguide bandpass filter with complementary split-ring resonators," IEEE Microw. Wireless Compon. Lett., Vol. 20, No. 8, 426-428, Aug. 2010. doi:10.1109/LMWC.2010.2049258
7. Dong, Y., T. Yang, and T. Itoh, "Substrate integrated waveguide loaded by complementary splitring resonators and its applications to miniaturized waveguide filters," IEEE Trans. Microw. Theory Tech., Vol. 57, No. 9, 2211-2222, Sep. 2009. doi:10.1109/TMTT.2009.2027156
8. Chen, C.-F., T. Y. Huang, C. P. Chou, and R. B. Wu, "Microstrip diplexers design with common resonator sections for compact size, but high isolation," IEEE Trans. Microw. Theory Tech., Vol. 54, No. 5, 1945-1952, May 2006. doi:10.1109/TMTT.2006.873613
9. Chen, H., L. Ran, J. Hangfu, X. Zhang, K. Chen, T. M. Grzegorczyk, and J. A. Kong, "Left handed material composed of only S-shaped resonators," Phys. Rev. lett., Vol. 70, No. 5, 1-4, 2004.
10. Horestani, A. K., M. D. Sindreu, J. Naqui, C. Fumeaux, and F. Martın, "S-shaped complementary mode suppression," IEEE Microw. Wireless Compon. Lett., Vol. 24, No. 3, 150-152, Mar. 2014. doi:10.1109/LMWC.2013.2291853