1. Liu, Q., Y. Liu, Y. Wu, M. Su, and J. Shen, "Compact wideband circularly polarized patch antenna for CNSS applications," IEEE Antennas Wirel. Propag. Lett., Vol. 12, 1280-1283, 2013.
doi:10.1109/LAWP.2013.2283218 Google Scholar
2. Sun, L., B.-H. Sun, H. Wu, J. Yuan, and W. Tang, "Broadband, wide beam circularly polarized antenna with a novel matching structure for satellite communications," Progress In Electromagnetics Research C, Vol. 59, 159-166, 2015.
doi:10.2528/PIERC15101101 Google Scholar
3. Han, R. C., S. S. Zhong, and J. Liu, "Broadband circularly polarised dielectric resonator antenna fed by wideband switched line coupler," Electron. Lett., Vol. 50, No. 10, 725-726, 2014.
doi:10.1049/el.2014.0809 Google Scholar
4. Schiffman, B. M., "A new class of broad-band microwave 90-degree phase shifters," IRE Trans. Microwave Theory Tech., Vol. 6, No. 2, 232-237, 1958.
doi:10.1109/TMTT.1958.1124543 Google Scholar
5. Lee, C. H. and Y. H. Chang, "An alternative implementation for fabricating a Schiffman phase shifter," Microwave Opt. Technol. Lett., Vol. 55, No. 1, 9-12, 2013.
doi:10.1002/mop.27266 Google Scholar
6. Guo, Y. X., Z. Y. Zhang, and L. C. Ong, "Improved wide-band Schiffman phase shifter," IEEE Trans. Microwave Theory Tech., Vol. 54, No. 3, 1196-1200, 2006.
doi:10.1109/TMTT.2005.864105 Google Scholar
7. Rhee, S., "Broadband Schiffman phase shifter using coupled suspended lines with tuning septums," Microwave Opt. Technol. Lett., Vol. 55, No. 5, 1036-1038, 2013.
doi:10.1002/mop.27494 Google Scholar
8. Zhang, Z., Y.-C. Jiao, S.-F. Cao, X.-M. Wang, and F.-S. Zhang, "Modified broadband Schiffman phase shifter using dentate microstrip and patterned ground plane," Progress In Electromagnetics Research Letters, Vol. 24, 9-16, 2011.
doi:10.2528/PIERL11041406 Google Scholar
9. Donelli, M., M. Rukanuzzaman, and C. E. Saavedra, "A methodology for the design of microwave systems and circuits using an evolutionary algorithm," Progress In Electromagnetics Research M, Vol. 31, 129-141, 2013.
doi:10.2528/PIERM13041607 Google Scholar
10. Donelli, M., C. Saavedra, and M. D. Rukanuzzaman, "Design and optimization of a broadband X-band bidirectional amplifier," Microwave Opt. Technol. Lett., Vol. 55, No. 8, 1730-1735, 2013.
doi:10.1002/mop.27712 Google Scholar
11. Azaro, R., G. Boato, M. Donelli, A. Massa, and E. Zeni, "Design of a prefractal monopolar antenna for 3.4–3.6GHz Wi-Max band portable devices," IEEE Antennas Wirel. Propag. Lett., Vol. 5, 116-119, 2006.
doi:10.1109/LAWP.2006.872427 Google Scholar
12. Donelli, M. and P. Febvre, "An inexpensive reconfigurable planar array for Wi-Fi applications," Progress In Electromagnetics Research C, Vol. 28, 71-81, 2012.
doi:10.2528/PIERC12012304 Google Scholar
13. Liu, Q., Y. Liu, J. Shen, S. Li, C. Yu, and Y. Lu, "Wideband single-layer 90◦ phase shifter using stepped impedance open stub and coupled-line with weak coupling," IEEE Microwave Wireless Compon. Lett., Vol. 24, No. 3, 176-178, 2014.
doi:10.1109/LMWC.2013.2295212 Google Scholar
14. Liu, Q., H. Liu, and Y. Liu, "Compact ultra-wideband 90◦ phase shifter using short-circuited stub and weak coupled line," Electron. Lett., Vol. 50, No. 20, 1454-1456, 2014.
doi:10.1049/el.2014.2271 Google Scholar
15. Sorn, M., R. Lech, and J. Mazur, "Simulation and experiment of a compact wideband 90◦ differential phase shifter," IEEE Trans. Microwave Theory Tech., Vol. 60, No. 3, 494-501, 2012.
doi:10.1109/TMTT.2011.2175244 Google Scholar
16. Wang, Y., M. E. Bialkowski, and A. M. Abbosh, "Double microstrip-slot transitions for broadband ±90◦ microstrip phase shifters," IEEE Microwave Wireless Compon. Lett., Vol. 22, No. 2, 58-60, 2012.
doi:10.1109/LMWC.2011.2181348 Google Scholar
17. Eom, S. Y. and H. K. Park, "New switched-network phase shifter with broadband characteristics," Microwave Opt. Technol. Lett., Vol. 38, No. 4, 255-257, 2003.
doi:10.1002/mop.11030 Google Scholar
18. Zheng, S. Y., W. S. Chan, and K. F. Man, "Broadband phase shifter using loaded transmission line," IEEE Microwave Wireless Compon. Lett., Vol. 20, No. 9, 498-500, 2010.
doi:10.1109/LMWC.2010.2050868 Google Scholar
19. Yeung, S. H., Q. Xue, and K. F. Man, "Broadband 90◦ differential phase shifter constructed using a pair of multisection radial line stubs," IEEE Trans. Microwave Theory Tech., Vol. 60, No. 9, 2760-2767, 2012.
doi:10.1109/TMTT.2012.2204899 Google Scholar
20. Zhang, W., Y. Liu, Y. Wu, W. Wang, M. Su, and J. Gao, "A modified coupled-line Schiffman phase shifter with short reference line," Progress In Electromagnetics Research C, Vol. 54, 17-27, 2014. Google Scholar
21. Shie, C. I., J. C. Cheng, S. C. Chou, and Y. C. Chiang, "Transdirectional coupled-line couplers implemented by periodical shunt capacitors," IEEE Trans. Microwave Theory Tech., Vol. 57, No. 12, 2981-2988, 2009.
doi:10.1109/TMTT.2009.2034219 Google Scholar
22. Pozar, D. M., Microwave Engineering, 4 Ed., John Wiley & Sons, New York, 2012.