A microstrip dual-mode dual-band bandpass filter using stepped impedance resonators (SIRs) is designed for dual-band wireless local area network (WLAN) applications at 2.4 and 5.2 GHz. By appropriately selecting the impedance ratio (Rz) and length ratio (α) of the SIRs, the harmonic frequencies can be tuned for generating the dual-bandpass response. Based on SIRs, a dual-mode dual-band bandpass filter is designed with one transmission zero. To improve the selectivity, another three transmission zeros in stopbands be created by introducing two stubs in input/output (I/O) lines. Two experimental filters are fabricated. Both simulated resulted and measured resulted are presented.
2. Chen, C. Y., C. Y. Hsu, and H. R. Chuang, "Design of miniature planar dual-band filter using dual-feeding structures and embedded resonators," IEEE Microw. Wireless Compon. Lett., Vol. 16, No. 12, 669-671, Dec. 2006.
doi:10.1109/LMWC.2006.885621
3. Chen, C.-Y. and C.-Y. Hsu, "A simple and effective method for microstrip dual-band filters design," IEEE Microw. Wireless Compon. Lett., Vol. 16, No. 3, 246-248, May 2006.
doi:10.1109/LMWC.2006.873584
4. Zhang, X. Y., J.-X. Chen, Q. Xue, and S.-M. Li, "Dual-band bandpass filters using stub-loaded resonators," IEEE Microw. Wireless Compon. Lett., Vol. 17, No. 8, 583-585, Aug. 2007.
doi:10.1109/LMWC.2007.901768
5. Wang, X.-H. and B.-Z. Wang, "Compact broadband dual-band bandpass filters using slotted ground structures," Progress In Electromagnetics Research, Vol. 82, 151-166, 2008.
doi:10.2528/PIER08030101
6. Wu, G.-L., W. Mu, X.-W. Dai, and Y.-C. Jiao, "Design of novel dual-band bandpass filter with microstrip meander-loop resonator and CSSRR DGS," Progress In Electromagnetics Research, Vol. 78, 17-24, 2008.
doi:10.2528/PIER07090301
7. Chen, F.-C. and Q.-X. Chu, "A compact dual-band bandpass filter using meandering stepped impedance resonators," Microw. Opt. Technol. Lett., Vol. 50, No. 10, 2619-2621, Oct. 2008.
doi:10.1002/mop.23720
8. Chang, S.-H., M.-H. Weng, and H. Kuan, "Design of a compact dual-band bandpass filter using trisection stepped impedance resonators," Microw. Opt. Technol. Lett., Vol. 49, No. 6, 1274-1277, Jun. 2007.
doi:10.1002/mop.22432
9. Chang, Y.-C., C.-H. Kao, M.-H. Weng, and R.-Y. Yang, "Design of the compact dual-band bandpass filter with high isolation for GPS/WLAN applications," IEEE Microw. Wireless Compon. Lett., Vol. 19, No. 12, 780-782, Dec. 2009.
doi:10.1109/LMWC.2009.2033523
10. Jiang, M., L.-M. Chang, and A. Chin, "Design of dual-passband microstrip bandpass filters with multi-spurious suppression," IEEE Microw. Wireless Compon. Lett., Vol. 20, No. 4, 199-201, Apr. 2010.
doi:10.1109/LMWC.2010.2042550
11. Bairavasubramanian, R., S. Pinel, J. Papapolymerou, J. L. C. Quendo, E. Rius, A. Manchec, and C. Person, "Dual-band filters for WLAN applications on liquid crystal polymer technology," IEEE MTT-S International Microwave Symposium Digest, 533-536, 2005.
doi:10.1109/MWSYM.2005.1516650
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