1. "Revision of part 15 of the commission’s rules regarding ultra-wideband transmission systems,", First Note and Order Federal Communications Commission, ET-Docket 98-153, 2002.
doi:10.1109/22.97492
2. Quirarte, J. L. R. and J. P. Starski, "Synthesis of Schiffman phase shifters," IEEE Trans. Microw. Theory Tech., Vol. 39, No. 11, 1885-1889, Nov. 1991.
doi:10.1109/TMTT.2005.864105
3. Guo, Y. X., Z. Y. Zhang, and L. C. Ong, "Improved wideband Schiffman phase shifter," IEEE Trans. Microw. Theory Tech., Vol. 54, No. 3, 1196-1200, Mar. 2006.
doi:10.1109/TMTT.2007.904051
4. Abbosh, A., "Ultra-wideband phase shifters," IEEE Trans. Microw. Theory Tech., Vol. 55, No. 9, 1935-1941, Sep. 2007.
doi:10.1109/LMWC.2010.2079320
5. Abbosh, A., "Broadband fixed phase shifters," IEEE Microw. Wireless Compon. Lett., Vol. 21, No. 1, 22-24, Jan. 2011.
doi:10.1049/iet-map:20070135
6. Sellal, K., L. Talbi, T. A. Denidni, and J. Lebel, "Design and implementation of a substrate integrated waveguide phase shifter," IET Microw. Antennas Propag., Vol. 2, No. 2, 194-199, 2008.
doi:10.1063/1.3025303
7. He, P., J. Gao, C. Marinis, P. Parimi, C. Vittoria, and V. Harris, "A microstrip tunable negative refractive index metamaterial and phase shifter," Appl. Phys. Lett., Vol. 93, No. 19, 193505-1-193505-3, 2008.
doi:10.1049/el:20083364
8. Zheng, S. Y., S. H. Yeung, W. S. Chan, K. F. Man, and S. H. Leung, "Improved broadband dumb-bell-shaped phase shifter using multi-se-ction stubs," Electron. Lett., Vol. 44, No. 7, 478-480, Mar. 2008.
9. Tang, X. and K. Mouthaan, "Design of a UWB phase shifter using shunt λ/4 stubs," IEEE MTT-S Int. Microw. Symp. Dig., 1021-1024, Jun. 2009.
doi:10.1002/0471754323
10. Caloz, C. and T. Itoh, Electromagnetic Metamaterials: Transmission Line Theory and Microwave, Wiley-IEEE Press, 2005.
doi:10.1109/TMTT.2012.2204899
11. 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. Microw. Theory Tech., Vol. 60, No. 9, 2760-2776, Sep. 2012.