1. Stutzman, W. L. and G. A. Thiele, Antenna Theory and Design, 2nd Edition, Wiley, New York, 1998.
2. Oh, S.-S. and L. Shafai, "Compensated circuit with characteristics of lossless double negative materials and its application to array antennas," IET Microw. Antennas Propag., Vol. 1, No. 1, 29-38, Feb. 2007.
doi:10.1049/iet-map:20050229 Google Scholar
3. Mirzaei, H. and G. V. Eleftheriades, "Arbitrary-angle squint-free beamforming in series-fed antenna arrays using non-Foster elements synthesized by negative-group-delay networks," IEEE Trans. Antennas Propag., Vol. 63, No. 5, 1997-2010, May 2015.
doi:10.1109/TAP.2015.2408364 Google Scholar
4. Zhu, M. and C.-T. M. Wu, "Negative group delay enabled artificial transmission line exhibiting squint-free, dominant mode, backward leakywave radiation," IEEE MTT-S Int. Microw. Symp. Dig., 309-312, Los Angeles, CA, USA, Aug. 2020. Google Scholar
5. Zhu, M. and C.-T. M.Wu, "Reconfigurable series feed network for squint-free antenna beamforming using distributed amplifier-based negative group delay circuit," Proc. 49th Eur. Microw. Conf. (EuMC), 256-259, Paris, France, Oct. 2019. Google Scholar
6. Zhu, M. and C.-T. M. Wu, "Reconfigurable non-Foster elements and squint-free beamforming networks using active transversal filter-based negative group delay circuit," IEEE Trans. Microw. Theory Techn., Vol. 70, No. 1, 222-231, Jan. 2022.
doi:10.1109/TMTT.2021.3074577 Google Scholar
7. Fonseca, N. J. G., A. Ali, and H. Aubert, "Cancellation of beam squint with frequency in serial beamforming network-fed linear array antennas," IEEE Antennas Propag. Mag., Vol. 54, No. 1, 32-39, Feb. 2012.
doi:10.1109/MAP.2012.6202510 Google Scholar
8. Cai, S. and J. Liu, "A printed wideband squintless traveling-wave antenna," IEEE Antennas Wireless Propag. Lett., Vol. 20, No. 8, 1473-1477, Aug. 2021.
doi:10.1109/LAWP.2021.3087598 Google Scholar
9. Mirzaei, H. and G. V. Eleftheriades, "Eliminating beam-deterioration in wideband linear series-fed antenna arrays using feed networks constructed by slow-wave transmission lines," IEEE Antennas Wireless Propag. Lett., Vol. 15, 798-801, 2016.
doi:10.1109/LAWP.2015.2475279 Google Scholar
10. Loecker, C., C. G. Salzburg, K. Herbertz, and T. Bertuch, "Series feeding network based on metamaterial compensation lines," IEEE J. Multiscale Multiphys. Comput. Techn., Vol. 2, 142-146, 2017.
doi:10.1109/JMMCT.2017.2756082 Google Scholar
11. Lai, A., K. M. K. H. Leong, and T. Itoh, "Novel series divider for antenna arrays with arbitrary element spacing based on a composite right/left-handed transmission line," Proc. 2005 Eur. Microw. Conf. (EuMC), 145-148, Paris, France, Oct. 2005. Google Scholar
12. Bemani, M. and S. Nikmehr, "Dual-band N-way series power divider using CRLH-TL metamaterials with application in feeding dual-band linear broadside array antenna with reduced beam deterioration," IEEE Trans. Circuits Syst. I, Reg. Papers, Vol. 60, No. 12, 3239-3246, Dec. 2013.
doi:10.1109/TCSI.2013.2255631 Google Scholar
13. Ueda, T., S. Yamamoto, Y. Kado, and T. Itoh, "Pseudo-traveling-wave resonator with magnetically tunable phase gradient of fields and its applications to beam-steering antennas," IEEE Trans. Microw. Theory Techn., Vol. 60, No. 10, 3043-3054, Oct. 2012.
doi:10.1109/TMTT.2012.2207737 Google Scholar
14. Ueda, T., Y. Kubo, T. Kaneda, M. Hara, Y. Takahashi, and T. Itoh, "Dispersion-free and tunable nonreciprocities in composite right-/left-handed metamaterials and their applications to beam squint reduction in leaky-wave antennas," IEEE Trans. Microw. Theory Techn., Vol. 67, No. 6, 2227-2237, Jun. 2019.
doi:10.1109/TMTT.2019.2909022 Google Scholar
15. Eleftheriades, G. V., M. A. Antoniades, and F. Qureshi, "Antenna applications of negativerefractive- index transmission-line structures," IET Microw. Antennas Propag., Vol. 1, No. 1, 12-22, Feb. 2007.
doi:10.1049/iet-map:20050345 Google Scholar
16. Antoniades, M. A. and G. V. Eleftheriades, "A CPS leaky-wave antenna with reduced beam deterioration using NRI-TL metamaterials," IEEE Trans. Antennas Propag., Vol. 56, No. 3, 708-721, Mar. 2008.
doi:10.1109/TAP.2008.916965 Google Scholar
17. Kossifos, K. M. and M. A. Antoniades, "A NRI-TL metamaterial leaky-wave antenna radiating at broadside with zero beam-deterioration," IEEE Antennas Wireless Propag. Lett., Vol. 17, No. 12, 2223-2227, Dec. 2018.
doi:10.1109/LAWP.2018.2871722 Google Scholar
18. Li, H., X. Guo, T. Yu, L. Zhu, and W. Wu, "Wideband continuously tunable phase shifter with phase slope tunability and low phase error," IEEE Trans. Microw. Theory Techn., Vol. 70, No. 4, 2147-2155, Apr. 2022.
doi:10.1109/TMTT.2022.3148429 Google Scholar
19. Wi, S.-H., Y.-S. Lee, and J.-G. Yook, "Wideband microstrip patch antenna with U-shaped parasitic elements," IEEE Trans. Antennas Propag., Vol. 55, No. 4, 1196-1199, Apr. 2007.
doi:10.1109/TAP.2007.893427 Google Scholar