A compact elliptic-function band-pass filter (BPF) is introduced using microstrip folded quasi multi-mode resonator. The prototype filter is synthesized from the two-port network and equivalent circuit models using available element value tables. To optimize the performance of the filter, electromagnetic simulation (EM) is used to tune the dimensions of the filter. The filter using dual cascaded quasi multi-mode resonators provides a very sharp cut-off frequency response with low insertion loss. It also realized a broad band pass-band, a compact size and two transmission zeros at both the lower and upper stop-bands. The filter is also evaluated by experiment and simulation with good agreement.
2. Lin, F. L., C. W. Chiu, and R. B. Wu, "Coplanar waveguide bandpass filter --- A ribbon-of-brick-wall design," IEEE Trans. Microwave Theory and Tech., Vol. 47, 1589-1596, 1995.
3. Kuo, Y.-K., C.-H. Wang, and C. H. Chen, "Novel reduced-size coplanar-waveguide bandpass filters," IEEE Microw. Wireless Compon. Lett., Vol. 11, 65-67, 2001.
4. Lin, Y.-S., W.-C. Ku, C.-H. Wang, and C. H. Chen, "Wideband coplanar-waveguide bandpass filters with good stopband rejection," IEEE Microw. Wireless Compon. Lett., Vol. 14, 422-424, 2004.
5. Chen, N.-W. and K.-C. Fang, "An ultra-broadband coplanar waveguide bandpass filter with sharp skirt selectivity," IEEE Microw. Wireless Compon. Lett., Vol. 17, 124-126, 2007.
6. Dib, N. I., L. P. B. Katehi, G. E. Ponchak, and R. N. Simons, "Theoretical and experimental characterization of coplanar waveguide discontinuities 49--53 for filter application," IEEE Trans. Microwave Theory and Tech., Vol. 39, 873-881, 1991.
7. Wang, S.-N. and N.-W. Chen, "Compact, ultra-broadband coplanar-waveguide bandpass filter with excellent stopband rejection," Progress In Electromagnetics Research B, Vol. 17, 15-28, 2009.
8. Razalli, M. S., A. Ismail, M. A. Mahdi, and M. N. bin Hamidon, "Novel compact microstrip ultra-wideband filter utilizing short-circuited stubs with less vias," Progress In Electromagnetics Research, Vol. 88, 91-104, 2008.
9. Sun, S., L. Zhu, and H.-H. Tan, "A compact wideband bandpass filter using transversal resonator and asymmetrical interdigital coupled lines," IEEE Microw. Wireless Compon. Lett., Vol. 18, 173-175, 2008.
10. Wang, H., Q.-X. Chu, and Q. Gong, "A compact wideband microstrip filter using folded multi-mode resonator," IEEE Microw. Wireless Compon. Lett., Vol. 19, 287-289, 2009.
11. Nosrati, M. and Z. Atlasbaf, "A novel model of small sized dual-band rectangular ring bandpass filter," 7th International Symp. on Antenna, Propagation & EM Theory, ISAPE'06, 26-29, 2006.
12. Shaman, H. and J.-S. Hong, "A novel ultra-wideband bandpass filter with pairs of transmission zeroes," IEEE Microw. Wireless Compon. Lett., Vol. 17, 121-123, 2007.
13. Nosrati, M. and S. K. Valashani, "A novel compact branch-line coupler using four coupled transmission lines," Microwave and Opt. Technol. Lett., Vol. 50, 1712-1714, 2008.
14. Malherbe, J. A. G., Microwave Transmission Line Filters, Artech House, INC, 1979.
15. Hsieh, L.-H. and K. Chang, "Compact elliptic-function low-pass filters using microstrip stepped-impedance hairpin resonators," IEEE Trans. Microwave Theory and Tech., Vol. 51, 193-199, 2003.