1. Oh, H., W. Lee, and H. Lee, "A better balun? done the design of a 4 : 1 wideband balun using a parallel-connected transmission-line balun," Microw. Magaz., Vol. 18, No. 1, 85-90, 2017.
doi:10.1109/MMM.2016.2616186        Google Scholar

2. Zhang, W., Y. Wu, W. Wang, and X. Shen, "Planar compact dual-band coupled-line balun with high isolation," China Commun., Vol. 14, 40-48, 2017.
doi:10.1109/CC.2017.7868173        Google Scholar

3. Yao, L., Y. Wu, M. Li, and Y. Liu, "Three-dimensional high-isolated dual-band balun using doublesided parallel-strip line with inserted conductor plane," Electron. Lett., Vol. 53, 1211-1213, 2017.
doi:10.1049/el.2017.1954        Google Scholar

4. Ahn, H.-R. and T. Itoh, "New isolation circuits of compact impedance-transforming 3-dB baluns for theoretically perfect isolation and matching," Trans. Microw. Theory Techn., Vol. 58, No. 12, 3892-3902, 2010.        Google Scholar

5. Wu, Y., L. Yao, W. Zhang, W. Wang, and Y. Liu, "A planar dual-band coupled-line balun with impedance transformation and high isolation," IEEE Access, Vol. 4, 9689-9701, 2016.
doi:10.1109/ACCESS.2016.2640187        Google Scholar

6. Aboualalaa, M., A.-B. Abdel-Rahman, A. Allam, H. Elsadek, and R.-K. Pokharel, "Design of a dual-band microstrip antenna with enhanced gain for energy harvesting applications," Antennas Wirel. Propag. Lett., Vol. 16, 1622-1626, 2017.
doi:10.1109/LAWP.2017.2654353        Google Scholar

7. Kanaya, H., T. Nakamura, K. Kawakami, and K. Yoshida, "Design of coplanar waveguide matching circuit for RF-CMOS front-end," Electron. Commun. Jpn II, Vol. 88, No. 7, 1017-1023, 2005.        Google Scholar

8. Li, X., L. Yang, S.-X. Gong, and Y.-J. Yang, "Dual-band and wideband design of a printed dipole antenna integrated with dual-band balun," Progress In Electromagnetics Research Letters, Vol. 6, 165-174, 2009.
doi:10.2528/PIERL08120504        Google Scholar

9. Xian, J. Z., X. Q. Lin, L. Y. Nie, J.W. Yu, and Y. Fan, "Wideband dual-polarization patch antenna array with parallel strip line balun feeding," IEEE Antennas Wireless Propag. Lett., Vol. 15, 1499-1501, 2016.        Google Scholar

10. Yu, J., Y. Sun, H. Zhu, F. Li, and Y. Fang, "Stacked-patch dual-band and dual-polarized antenna with broadband baluns for WiMAX and WLAN applications," Progress In Electromagnetics Research M, Vol. 68, 41-52, 2018.
doi:10.2528/PIERM18022501        Google Scholar

11. Zhang, Z., M. F. Iskander, J. C. Langer, and J. Mathews, "Dual-band WLAN dipole antenna using an internal matching circuit," IEEE Trans. Antennas Propagat., Vol. 53, No. 5, 1813-1818, 2005.
doi:10.1109/TAP.2005.846784        Google Scholar

12. Gao, J. P., X. X. Yang, J. S. Zhang, and J. X. Xiao, "A printed volcano smoke antenna for UWB and WLAN communications," Progress In Electromagnetics Research Letters, Vol. 4, 55-61, 2008.
doi:10.2528/PIERL08051102        Google Scholar

13. Ahn, H. and T. Itoh, "Isolation circuit of impedance-transforming 3-dB compact baluns for near perfect output matching and isolation," IEEE MTT-S International Microwave Symposium, 113-116, Anaheim, CA, 2010.        Google Scholar

14. Zhang, W., Y. Liu, Y. Wu, W. Wang, M. Su, and J. Gao, "A complex Impedance-transforming coupled-line balun," Progress In Electromagnetics Research Letters, Vol. 48, 123-128, 2014.
doi:10.2528/PIERL14062402        Google Scholar

15. Gupta, R. and M. S. Hashmi, "High impedance transforming simplified Balun architecture in microstrip technology," Microw. Optical Technol. Lett., Vol. 60, No. 12, 3019-3023, 2018.
doi:10.1002/mop.31450        Google Scholar

16. Nikravan, M.-A. and Z. Atlasbaf, "T-section dual-band impedance transformer for frequencydependent complex impedance loads," Electron. Lett., Vol. 47, No. 9, 551-553, 2011.
doi:10.1049/el.2010.7452        Google Scholar

17. Monzon, C., "Analytical derivation of a two-section impedance transformer for a frequency and its first harmonic," IEEE Microw. Wirel. Compon. Lett., Vol. 12, No. 10, 381-382, Oct. 2002.
doi:10.1109/LMWC.2002.804558        Google Scholar