1. Gao, W., Y. Zhang, D. Ramanujan, K. Ramani, Y. Chen, C. B. Williams, C. C. Wang, Y. C. Shin, S. Zhang, and P. D. Zavattieri, "The status, challenges, and future of additive manufacturing in engineering," Computer-Aided Design, Vol. 69, 65-89, 2015, [online], available: http://www.sciencedirect.com/science/article/pii/S001044851500.
doi:10.1016/j.cad.2015.04.001 Google Scholar
2. Tofail, S. A., E. P. Koumoulos, A. Bandyopadhyay, S. Bose, L. O’Donoghue, and C. Charitidis, "Additive manufacturing: Scientific and technological challenges, market uptake and opportunities," Materials Today, Vol. 21, No. 1, 22-37, 2018, [online], available: http://www.sciencedirect.com/science/article/pii/S13697021173.
doi:10.1016/j.mattod.2017.07.001 Google Scholar
3. Ituarte, I. F., E. Coatanea, M. Salmi, J. Tuomi, and J. Partanen, "Additive manufacturing in production: A study case applying technical requirements," Physics Procedia, Vol. 78, 357– 366, 2015, 15th Nordic Laser Materials Processing Conference, Nolamp 15, [online], available: http://www.sciencedirect.com/science/article/pii/S1875389215015400. Google Scholar
4. Gibson, I., B. Stucker, and D. Rosen, Additive Manufacturing Technologies, Springer-Verlag, 2015.
doi:10.1007/978-1-4939-2113-3
5. Attaran, M., "The rise of 3-D printing: The advantages of additive manufacturing over traditional manufacturing," Business Horizons, Vol. 60, No. 5, 677-688, 2017, [online], available: http://www.sciencedirect.com/science/article/pii/S0007681317300897.
doi:10.1016/j.bushor.2017.05.011 Google Scholar
6. DebRoy, T., H. Wei, J. Zuback, T. Mukherjee, J. Elmer, J. Milewski, A. Beese, A. Wilson- Heid, A. De, and W. Zhang, "Additive manufacturing of metallic components — Process, structure and properties," Progress in Materials Science, Vol. 92, 112-224, 2018, [online], available: http://www.sciencedirect.com/science/article/pii/S0079642517301172.
doi:10.1016/j.pmatsci.2017.10.001 Google Scholar
7. Frazier, W. E., "Metal additive manufacturing: A review," Journal of Materials Engineering and Performance, Vol. 23, No. 6, 1917-1928, Jun. 2014, [online], available: https://doi.org/10.1007/s11665-014-0958-z.
doi:10.1007/s11665-014-0958-z Google Scholar
8. Herzog, D., V. Seyda, E. Wycisk, and C. Emmelmann, "Additive manufacturing of metals," Acta Materialia, Vol. 117, 371-392, 2016, [online], available: http://www.sciencedirect.com/science/article/pii/S1359645416305158.
doi:10.1016/j.actamat.2016.07.019 Google Scholar
9. Atzeni, E. and A. Salmi, "Economics of additive manufacturing for end-usable metal parts," The International Journal of Advanced Manufacturing Technology, Vol. 62, No. 9, 1147-1155, Oct. 2012, [online], available: https://doi.org/10.1007/s00170-011-3878-1. Google Scholar
10. Huang, Y., X. Gong, S. Hajela, and W. J. Chappell, "Layer-by-layer stereolithography of three-dimensional antennas," 2005 IEEE Antennas and Propagation Society International Symposium, Vol. 1A, 276-279, Jul. 2005. Google Scholar
11. Maas, J., B. Liu, S. Hajela, Y. Huang, X. Gong, and W. J. Chappell, "Laser-based layer-by-layer polymer stereolithography for high-frequency applications," Proceedings of the IEEE, Vol. 105, No. 4, 645-654, Apr. 2017.
doi:10.1109/JPROC.2016.2629179 Google Scholar
12. Adams, J. J., E. B. Duoss, T. F. Malkowski, M. J. Motala, B. Y. Ahn, R. G. Nuzzo, J. T. Bernhard, and J. A. Lewis, "Conformal printing of electrically small antennas on threedimensional surfaces," Advanced Materials, Vol. 23, No. 11, 1335-1340, 2011, [online], available: https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.201003734.
doi:10.1002/adma.201003734 Google Scholar
13. Ghazali, M. I. M., E. Gutierrez, J. C. Myers, A. Kaur, B. Wright, and P. Chahal, "Affordable 3D printed microwave antennas," 2015 IEEE 65th Electronic Components and Technology Conference (ECTC), 240-246, May 2015.
doi:10.1109/ECTC.2015.7159599 Google Scholar
14. Van der Vorst, M. and J. Gumpinger, "Applicability of 3D printing techniques for compact Ku-band medium/high-gain antennas," 2016 10th European Conference on Antennas and Propagation (EuCAP), 1-4, Apr. 2016. Google Scholar
15. Tech, O., "Metal 3D printed custom antennas,", 2018, [online], available: https://www.optisys.tech/. Google Scholar
16. Foged, L. J., A. Giacomini, R. Morbidini, F. Saccardi, V. Schirosi, M. Boumans, B. Gerg, and D. Melachrinos, "Investigation of additive manufacturing for broadband choked horns at X/Ku band," IEEE Antennas and Wireless Propagation Letters, Vol. 17, No. 11, 2003-2007, Nov. 2018.
doi:10.1109/LAWP.2018.2868611 Google Scholar
17. Hansen, R. C. and R. E. Collin, Small Antenna Handbook, Wiley-IEEE Press, 2012.
18. Wheeler, H. A., "Fundamental limitations of small antennas," Proceedings of the IRE, Vol. 35, No. 12, 1479-1484, Dec. 1947.
doi:10.1109/JRPROC.1947.226199 Google Scholar
19. Chu, L. J., "Physical limitations of omni-directional antennas," Journal of Applied Physics, Vol. 19, No. 12, 1163-1175, 1948, [online], available: http://dx.doi.org/10.1063/1.1715038.
doi:10.1063/1.1715038 Google Scholar
20. McLean, J. S., "A re-examination of the fundamental limits on the radiation Q of electrically small antennas," IEEE Transactions on Antennas and Propagation, Vol. 44, No. 5, 672, May 1996.
doi:10.1109/8.496253 Google Scholar
21. Yaghjian, A. D. and H. R. Stuart, "Lower bounds on the Q of electrically small dipole antennas," IEEE Transactions on Antennas and Propagation, Vol. 58, No. 10, 3114-3121, Oct. 2010.
doi:10.1109/TAP.2010.2055790 Google Scholar
22. Kim, O. S., "Rapid prototyping of electrically small spherical wire antennas," IEEE Transactions on Antennas and Propagation, Vol. 62, No. 7, 3839-3842, Jul. 2014.
doi:10.1109/TAP.2014.2317489 Google Scholar
23. Rowell, C. and E. Y. Lam, "Mobile-phone antenna design," IEEE Antennas and Propagation Magazine, Vol. 54, No. 4, 14-34, Aug. 2012.
doi:10.1109/MAP.2012.6309152 Google Scholar
24. Wong, H., K. Luk, C. H. Chan, Q. Xue, K. K. So, and H. W. Lai, "Small antennas in wireless communications," Proceedings of the IEEE, Vol. 100, No. 7, 2109-2121, Jul. 2012.
doi:10.1109/JPROC.2012.2188089 Google Scholar
25. Croq, F. and D. M. Pozar, "Millimeter-wave design of wide-band aperture-coupled stacked microstrip antennas," IEEE Transactions on Antennas and Propagation, Vol. 39, No. 12, 1770-1776, Dec. 1991.
doi:10.1109/8.121599 Google Scholar
26. Targonski, S. D., R. B. Waterhouse, and D. M. Pozar, "Design of wide-band aperture-stacked patch microstrip antennas," IEEE Transactions on Antennas and Propagation, Vol. 46, No. 9, 1245-1251, Sep. 1998.
doi:10.1109/8.719966 Google Scholar
27. Quijano, J. L. A. and G. Vecchi, "Optimization of an innovative type of compact frequency-reconfigurable antenna," IEEE Transactions on Antennas and Propagation, Vol. 57, No. 1, 9-18, Jan. 2009.
doi:10.1109/TAP.2008.2009649 Google Scholar
28. Quijano, J. L. A. and G. Vecchi, "Optimization of a compact frequency- and environment-reconfigurable antenna," IEEE Transactions on Antennas and Propagation, Vol. 60, No. 6, 2682-2689, Jun. 2012.
doi:10.1109/TAP.2012.2194634 Google Scholar
29. Rodrıguez, D. O., M. A. Saavedra, G. A. Ramırez, and J. L. Araque, "Realization of a compact reconfigurable antenna for mobile communications," 2014 IEEE-APS Topical Conference on Antennas and Propagation in Wireless Communications (APWC), 284-287, Aug. 2014.
doi:10.1109/APWC.2014.6905549 Google Scholar
30. Arroyave, G. A. R. and J. L. A. Quijano, "Dual-port reconfigurable planar antennas for diversity and duplexing applications," 2016 IEEE International Symposium on Antennas and Propagation (APSURSI), 1247-1248, Jun. 2016.
doi:10.1109/APS.2016.7696331 Google Scholar
31. Byndas, A., R. Hossa, M. E. Bialkowski, and P. Kabacik, "Investigations into operation of single- and multi-layer configurations of planar inverted-F antenna," IEEE Antennas and Propagation Magazine, Vol. 49, No. 4, 22-33, Aug. 2007.
doi:10.1109/MAP.2007.4385593 Google Scholar
32. Huynh, M. and W. Stutzman, "Ground plane effects on planar inverted-F antenna (PIFA) performance," IEE Proceedings — Microwaves, Antennas and Propagation, Vol. 150, No. 4, 209-213, Aug. 2003.
doi:10.1049/ip-map:20030551 Google Scholar
33. Best, S. R., "The significance of ground-plane size and antenna location in establishing the performance of ground-plane-dependent antennas," IEEE Antennas and Propagation Magazine, Vol. 51, No. 6, 29-43, Dec. 2009.
doi:10.1109/MAP.2009.5433095 Google Scholar
34. Anguera, J., A. Andujar, M.-C. Huynh, C. Orlenius, C. Picher, and C. Puente, "Advances in antenna technology for wireless handheld devices," International Journal of Antennas and Propagation, Vol. 2013, No. 1, 1-25, 2013, [online], available: https://doi.org/10.1155/2013/838364.
doi:10.1155/2013/838364 Google Scholar
35. Anguera, J., C. Picher, A. Bujalance, and A. Andujar, "Ground plane booster antenna technology for smartphones and tablets," Microwave and Optical Technology Letters, Vol. 58, No. 6, 1289-1294, 2016, [online], available: https://onlinelibrary.wiley.com/doi/abs/10.1002/mop.29788.
doi:10.1002/mop.29788 Google Scholar
36. Yoon, H. S. and S. O. Park, "A dual-band internal antenna of PIFA type for Bluetooth/WLAN in mobile handsets," 2007 IEEE Antennas and Propagation Society International Symposium, 665-668, Jun. 2007.
doi:10.1109/APS.2007.4395581 Google Scholar
37. Serra, A. A., P. Nepa, G. Manara, and R. Massini, "A low-profile linearly polarized 3D PIFA for handheld GPS terminals," IEEE Transactions on Antennas and Propagation, Vol. 58, No. 4, 1060-1066, Apr. 2010.
doi:10.1109/TAP.2010.2041162 Google Scholar
38. Khan, P., A. Abdullah Al-Hadi, P. J. Soh, M. T. Ali, S. S. Al-Bawri, and Owais, "Design and optimization of a dual-band sub-6GHz four port mobile terminal antenna performance in the vicinity of user's hand," Progress In Electromagnetics Research C, Vol. 85, 141-153, 2018.
doi:10.2528/PIERC18050101 Google Scholar
39. Nguyen-Trong, N., A. Piotrowski, and C. Fumeaux, "A frequency-reconfigurable dual-band low-profile monopolar antenna," IEEE Transactions on Antennas and Propagation, Vol. 65, No. 7, 3336-3343, Jul. 2017.
doi:10.1109/TAP.2017.2702664 Google Scholar
40. Wang, D., G. Wen, and Q. Rao, "A 3D compact pent-band antenna for wireless mobile communication," 2008 IEEE Antennas and Propagation Society International Symposium, 1-4, Jul. 2008. Google Scholar
41. Li, G., H. Zhai, T. Li, X. Y. Ma, and C.-H. Liang, "Design of a compact UWB antenna integrated with GSM/WCDMA/WLAN bands," Progress In Electromagnetics Research, Vol. 136, 409-419, 2013.
doi:10.2528/PIER12120604 Google Scholar
42. Alibakhshikenari, M., B. S. Virdee, and E. Limiti, "Triple-band planar dipole antenna for omnidirectional radiation," Microwave and Optical Technology Letters, Vol. 60, No. 4, 1048-1051, 2018, [online], available: https://onlinelibrary.wiley.com/doi/abs/10.1002/mop.31098.
doi:10.1002/mop.31098 Google Scholar
43. Alibakhshikenari, M., B. S. Virdee, A. Ali, and E. Limiti, "Miniaturised planar-patch antenna based on metamaterial L-shaped unit-cells for broadband portable microwave devices and multiband wireless communication systems," IET Microwaves, Antennas Propagation, Vol. 12, No. 7, 1080-1086, 2018.
doi:10.1049/iet-map.2016.1141 Google Scholar
44. Alibakhshikenari, M., E. Limiti, M. Naser-Moghadasi, B. S. Virdee, and R. Sadeghzadeh, "A new wideband planar antenna with band-notch functionality at GPS, Bluetooth and WiFi bands for integration in portable wireless systems," AEU — International Journal of Electronics and Communications, Vol. 72, 79-85, 2017, [online], available: http://www.sciencedirect.com/science/article/pii/S1434841116309955.
doi:10.1016/j.aeue.2016.11.023 Google Scholar
45. Sravani, P. and M. Rao, "Design of 3D antennas for 24 GHz ISM band applications," 2015 28th International Conference on VLSI Design, 470-474, Jan. 2015.
doi:10.1109/VLSID.2015.85 Google Scholar
46. Meneendez, L. G., O. S. Kim, F. Persson, M. Nielsen, and O. Breinbjerg, "3D printed 20/30-GHz dual-band offset stepped-reflector antenna," 2015 9th European Conference on Antennas and Propagation (EuCAP), 1-2, Apr. 2015. Google Scholar
47. Gjokaj, V., P. Chahal, J. Papapolymerou, and J. D. Albrecht, "A novel 3D printed Vivaldi antenna utilizing a substrate integrated waveguide transition," 2017 IEEE International Symposium on Antennas and Propagation USNC/URSI National Radio Science Meeting, 1253-1254, Jul. 2017. Google Scholar
48. Jofre, L., B. A. Cetiner, and F. D. Flaviis, "Miniature multi-element antenna for wireless communications," IEEE Transactions on Antennas and Propagation, Vol. 50, No. 5, 658-669, May 2002.
doi:10.1109/TAP.2002.1011232 Google Scholar
49. Harrington, R., "On the gain and beamwidth of directional antennas," IRE Transactions on Antennas and Propagation, Vol. 6, No. 3, 219-225, Jul. 1958.
doi:10.1109/TAP.1958.1144605 Google Scholar
50. Ramırez Arroyave, G. A. and J. L. Araque Quijano, "Broadband characterization of 3D printed samples with graded permittivity," 2018 International Conference on Electromagnetics in Advanced Applications (ICEAA), 584-588, Sep. 2018.
doi:10.1109/ICEAA.2018.8520349 Google Scholar
51. Arroyave, G. A. R. and J. L. A. Quijano, "Evaluation of additive manufacturing processes for 3-D multiband antennas," 2018 International Conference on Electromagnetics in Advanced Applications (ICEAA), 589-592, Sep. 2018.
doi:10.1109/ICEAA.2018.8520514 Google Scholar