This paper presents a novel frequency selective window for waveguide filters. It has a resonant characteristic with two attenuation poles on both sides of a passband, that is, a dual-behavior resonance. Such frequency selective windows make it possible to construct a compact bandpass filter having multiple attenuation poles without any additional coupling structures. As design examples, we show 3-pole Chebyshev waveguide filters with six attenuation poles in both the microwave and the millimeter-wave regions. The validity of the present filters is proven by the comparison of the frequency characteristics between the calculated and the measured results.
1. Shen, T. and K. A. Zaki, "Length reduction of evanescent-mode ridge waveguide bandpass filters," Progress In Electromagnetics Research, Vol. 40, 71-90, 2003. doi:10.2528/PIER02082206
2. Bahrami, H., M. Hakkak, and A. Pirhadi, "Analysis and design of highly compact bandpass waveguide filter using complementary split ring resonators (CSRR)," Progress In Electromagnetics Research, Vol. 80, 107-122, 2008. doi:10.2528/PIER07111203
3. Ghorbaninejad, H. and M. Khalaj-Amirhosseini, "Compact bandpass filters utilizing dielectric filled waveguides," Progress In Electromagnetics Research B, Vol. 7, 105-115, 2008. doi:10.2528/PIERB08031101
4. Quendo, C., E. Rius, and C. Person, "Narrow bandpass filters using dual-behavior resonators," IEEE Trans. Microwave Theory Tech., Vol. 51, No. 3, 734-743, Mar. 2003. doi:10.1109/TMTT.2003.808729
5. Quendo, C., E. Rius, and C. Person, "Narrow bandpass filters using dual-behavior resonators based on stepped impedance stubs and different-length stubs," IEEE Trans. Microwave Theory Tech., Vol. 52, No. 3, 1034-1044, Mar. 2004. doi:10.1109/TMTT.2004.823582
6. Piloni, M., R. Ravenelli, and M. Guglielmi, "Resonant aperture filters in rectagular waveguide," IEEE MTT-S Int. Microwave Symp. Dig., 911-914, Anaheim, CA, Jun. 1999.
7. Capurso, M., M. Piloni, and M. Guglielmi, "Resonant aperture filters: Improven out-of-band rejection and size reduction," Proc. of 31st European Microwave Conf., Vol. 1, 331-334, London, UK, Sep. 2001.
8. Ohira, M., H. Deguchi, M. Tsuji, and H. Shigesawa, "Novel waveguide filters with multiple attenuation poles using dual-behavior resonance of frequency-selective surfaces," IEEE Trans. Microwave Theory Tech., Vol. 53, No. 11, 3320-3326, Nov. 2005. doi:10.1109/TMTT.2005.857334
9. Ohira, M., H. Deguchi, M. Tsuji, and H. Shigesawa, "Circuit synthesis for compact waveguide filters with closely-spaced frequency selective surfaces," 10th Int. Symp. on Microwave and Optical Tech., 811-814, Fukuoka, Japan, Aug. 2005.
10. Ohira, M., H. Deguchi, M. Tsuji, and H. Shigesawa, "A new dual-behavior FSS resonator for waveguide filter with multiple attenuation poles," Proc. of 35th European Microwave Conf., 189-192, Paris, France, Oct. 2005.
11. Ohira, M., H. Deguchi, M. Tsuji, and H. Shigesawa, "A novel waveguide bandpass filter with multiple attenuation poles using four-armed square-loop FSSs," IEICE Trans. Electron. (Japanese Edition), Vol. 89, No. 7, 458-465, Jul. 2006.
12. Seager, R. D., J. C. Vardaxoglou, and D. S. Lockyer, "Close coupled resonant aperture inserts for waveguide filtering applications ," IEEE Microw. Wireless Comp. Lett., Vol. 11, No. 3, 112-114, Mar. 2001. doi:10.1109/7260.915620
13. Monorchio, A., G. Manara, U. Serra, G. Marola, and E. Pagana, "Design of waveguide filters by using genetically optimized frequency selective surface," IEEE Microw. Wireless Comp. Lett., Vol. 15, No. 6, 407-409, Jun. 2005. doi:10.1109/LMWC.2005.850482
14. Ohira, M., H. Deguchi, and M. Tsuji, A novel resonant window having dual-behavior resonance for psedo-elliptic waveguide filter, Proc. of 36th European Microwave Conf., 1083-1086, Manchester, England, Sep. 2006.
15. Matthaei, G. L., L. Young, and E. M. T. Jones, "Microwave Filters, Impedance-Matching Networks, and Coupling Structures," McGraw-Hill, New York, 1964.