Progress In Electromagnetics Research
ISSN: 1070-4698, E-ISSN: 1559-8985
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By R.-Y. Yang, C.-M. Hsiung, C.-Y. Hung, and C.-C. Lin

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In this paper, we presented the design of a high performance diplexer for applications of global positioning system (GPS) at 1.575 GHz and wireless local area network (WLAN) at 2.4 GHz, simultaneously. Two bandpass filters (BPFs) using the modified stepped-impedance resonators (SIRs) operated at 1.575 GHz and 2.4 GHz are main blocks for the proposed diplexer. By discussing and analyzing the admittance of the even and odd modes, the transmission zero of the modified SIR can be found, and the location of the transmission zero can be precisely predicted, thus having a wide and deep stopband for the BPFs, in turn the high performance diplexer. Furthermore, due to the appearance of the transmission zeros near the passband edges, the passband selectivity of the BPFs as well as the diplexer can be improved. By using the impedance matching between two BPFs, a high isolation of 50 dB between two channels is obtained. The proposed diplexer was designed, fabricated and measured. The simulated and measured results had a good agreement with the proposed design concept.

R.-Y. Yang, C.-M. Hsiung, C.-Y. Hung, and C.-C. Lin, " design of a high band isolation diplexer for GPS and WLAN system using modified stepped - impedance resonators ," Progress In Electromagnetics Research, Vol. 107, 101-114, 2010.

1. Xiong, J. P., L. Liu, X. M. Wang, J. Chen, and Y. L. Zhao, "Dual-band printed bent slots antenna for WLAN applications," Journal of Electromagnetic Waves and Applications, Vol. 22, No. 11-12, 1509-1515, 2008.

2. Hu, X., Q. Zhang, and S. He, "Compact dual-band rejection filter based on complementary meander line split ring resonator," Progress In Electromagnetics Research Letters, Vol. 8, 181-190, 2009.

3. Lee, C. H., I. C. Wang, and C. I. G. Hsu, "Dual-band balanced BPF using ╬╗\4 stepped-impedance resonators and folded feed lines," Journal of Electromagnetic Waves and Applications, Vol. 23, No. 17-18, 2441-2449, 2009.

4. Ren, W., "Compact dual-band slot antenna for 2.4/5 GHz WLAN applications," Progress In Electromagnetics Research B, Vol. 8, 319-327, 2008.

5. Yao, W. H., A. E. Abdelmonem, J. F. Liang, X. P. Liang, K. A. Zaki, and A. Martin, "Wide-band waveguide and ridge waveguide T-junctions for diplexer applications," IEEE Trans. Microw. Theory Tech., Vol. 41, 2166-2173, 1993.

6. Han, S., X.-L.Wang, Y. Fan, Z. Yang, and Z. He, "The generalized Chebyshev substrate integrated waveguide diplexer," Progress In Electromagnetics Research, Vol. 73, 29-38, 2007.

7. Strassner, B. and K. Chang, "Wide-band low-loss high-isolation microstrip periodic-stub diplexer for multiple-frequency applications ," IEEE Trans. Microw. Theory Tech., Vol. 49, 1818-1820, 2001.

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, 1945-1952, 2006.

9. Deng, P. H., C. H. Wang, and C. H. Chen, "Compact microstrip diplexers based on a dual-passband filter," Proceedings of Asia-Pacific Microwave Conference, 2006.

10. Weng, M. H., C. Y. Hung, and Y. K. Su, "A hairpin line diplexer for direct sequence ultra-wideband wireless communications," IEEE Microw. Wireless Compon. Lett., Vol. 17, 519-521, 2007.

11. Ye, C. S., Y. K. Su, M. H. Weng, and C. Y. Hung, "A microstrip ring-like diplexer for bluetooth and ultra wide band (UWB) application," Microwave & Opt. Tech. Lett., Vol. 51, 1518-1520, 2009.

12. Huang, C. Y., M. H. Weng, C. S. Ye, and Y. X. Xu, "A high band isolation and wide stopband diplexer using dual-mode stepped-impedance resonators," Progress In Electromagnetics Research, Vol. 100, 299-308, 2010.

13. Yang, R. Y., C. M. Hsiung, C. Y. Hung, and C. C. Lin, "A high performance bandpass filter with a wide and deep stopband by using square stepped impedance resonators," Journal of Electromagnetic Waves and Applications, Vol. 24, 1673-1683, 2010.

14. Weng, M. H., C. H. Kao, and Y. C. Chang, "A compact dual-band bandpass ¯lter with high band selectivity using cross-coupled asymmetric SIRs for WLANs," Journal of Electromagnetic Waves and Applications, Vol. 24, No. 2, 161-168, 2010.

15. Hong, J. S. and M. J. Lancaster, Microstrip Filters for RF/Microwave Application, John Wiley and Sons, 2001.

16. IE3D Simulator, Zeland Software, Inc., 1997.

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