In this paper, a new technique to realize lumped dual-band impedance transformers for arbitrary frequency-dependent complex loads is proposed. For the complex impedance transforming, closed-form design equations are presented for a series-shunt and a shunt-series type and a concept of combination is also presented. They use the proposed equation of input impedance. This equation can easily and exactly obtain the input impedance of any two-port network using the ABCD matrix. Then, in order to realize dual-band operation, four topologies comprising two types and a design method are presented. This technique is numerically demonstrated by various examples with excellent results and it has advantages of simplicity, intuitiveness and versatility because it is a general solution for complex impedance transforming. The proposed dual-band impedance transforming technique can be utilized for practical matching problems such as microwave amplifiers and other devices.
"A Dual-Band Impedance Transforming Technique with Lumped Elements for Frequency-Dependent Complex Loads," Progress In Electromagnetics Research,
Vol. 136, 123-139, 2013. doi:10.2528/PIER12111811
1. Chow, Y. L. and K. L. Wan, "A transformer of one-third wavelength in two sections-for a frequency and its first harmonic," IEEE Microwave Wireless Components Letters, Vol. 12, No. 1, 22-23, Jan. 2002. doi:10.1109/7260.975723
2. Monzon, C., "A small dual-frequency transformer in two sections," IEEE Transaction on Microwave Theory Techniques, Vol. 51, No. 4, 1157-1161, Apr. 2003. doi:10.1109/TMTT.2003.809675
3. Wu, Y., Y. Liu, and S. Li, "A Compact pi-structure dual band transformer," Progress In Electromagnetics Research, Vol. 88, 121-134, 2008. doi:10.2528/PIER08102601
4. Sophocles, J. and A. Orfanidis, "Two-section dual-band Chebyshev impedance transformer," IEEE Microwave Wireless Components Letters, Vol. 13, No. 9, 382-384, Sep. 2003. doi:10.1109/LMWC.2003.817135
5. Castaldi, G., V. Fiumara, and I. Gallina, "An exact synthesis method for dual-band Chebyshev impedance transformers," Progress In Electromagnetics Research, Vol. 86, 305-319, 2008. doi:10.2528/PIER08100605
6. Kuo, J.-T., C.-Y. Fan, and S.-C. Tang, "Dual-wideband bandpass ¯llters with extended stopband based on coupled-line and coupled three-line resonators," Progress In Electromagnetics Research, Vol. 124, 1-15, 2012. doi:10.2528/PIER11120103
7. Wu, L., Z. Sun, H. Yilmaz, and M. Berroth, "A dual-frequency Wilkinson power divider," IEEE Transaction on Microwave Theory Techniques, Vol. 54, No. 1, 278-284, 2006. doi:10.1109/TMTT.2005.860300
8. Li, B., X. Wu, N. Yang, and W. Wu, "Dual-band equal/unequal Wilkinson power dividers based on coupled-line section with short-circuited stub," Progress In Electromagnetics Research, Vol. 111, 163-178, 2011. doi:10.2528/PIER10110108
9. Li, J. C., Y. L.Wu, Y. A. Liu, J. Y. Shen, S. L. Li, and C. P. Yu, "A generalized coupled-line dual-band Wilkinson power divider with extended ports," Progress In Electromagnetics Research, Vol. 129, 197-214, 2012.
10. Fagotti, R., A. Cidronali, and G. Manes, "Concurrent hex-band GaN power amplifier for wireless communication systems," IEEE Microwave and Wireless Components Letters, Vol. 21, No. 2, 89-91, 2011.
11. Chen, W., S. A. Bassam, X. Li, Y. Liu, K. Rawat, M. Helaoui, F. M. Ghannouchi, and Z. Feng, "Design and linearization of concurrent dual-band Doherty power amplifier with frequency-dependent power ranges ," IEEE Transaction on Microwave Theory and Techniques, Vol. 59, No. 10, 2537-2546, Oct. 2011. doi:10.1109/TMTT.2011.2164089
12. Chen, X. Q., X. W. Shi, Y. C. Guo, and C. M. Xiao, "A novel dual band transmitter using microstrip defected ground structure," Progress In Electromagnetics Research, Vol. 83, 1-11, 2008. doi:10.2528/PIER08041503
13. Wu, Y., Y. Liu, and S. Li, "A dual-frequency transformer for complex impedances with two unequal sections," IEEE Microwave Wireless Components Letters, Vol. 19, No. 2, 77-79, 2009. doi:10.1109/LMWC.2008.2011315
14. Liu, X., Y. Liu, S. Li, F. Wu, and Y. Wu, "A three-section dual-band transformer for frequency-dependent complex load impedance," IEEE Microwave Wireless Components Letters, Vol. 19, No. 10, 611-613, Oct. 2009.
15. Chuang, M. L., "Dual-band impedance transformer using two-section shunt stubs," IEEE Transaction on Microwave Theory Techniques, Vol. 58, No. 5, 1257-1263, May 2010. doi:10.1109/TMTT.2010.2045560
16. Nikravan, M. A. and Z. Atlasbaf, "T-section dual-band impedance transformer for frequency-dependent complex loads," Electronics Letters, Vol. 47, No. 9, 551-553, Apr. 2011. doi:10.1049/el.2010.7452
17. Li, S., B. H. Tang, Y. A. Liu, S. L. Li, C. P. Yu, and Y. L. Wu, "Miniaturized dual-band matching technique based on coupled-line transformer for dual-band power amplifiers design," Progress In Electromagnetics Research, Vol. 131, 195-210, 2012.
18. Liu, Y., Y.-J. Zhao, and Y. Zhou, "Lumped dual-frequency impedance transformers for frequency-dependent complex loads," Progress In Electromagnetics Research, Vol. 126, 121-138, 2012. doi:10.2528/PIER11121207
19. Pozar, D. M., Microwave Engineering, 3rd Ed., Wiley, New York, 2005.
20. Medley, M. W., Microwave and RF Circuits: Analysis, Synthesis, and Design, Artech House, 1993.
21. Caloz, C. and T. Itoh, Electromagnetic Metamaterials: Transmission Line Theory and Microwave Applications, Wiley, New York, 2006.