In this paper, a broadband planar modified quasi-Yagi antenna using a two-element log-periodic dipole array as a driven element is proposed. To feed the two-element log-periodic dipole array, a simple microstrip to stripline transition as a balun is designed, which converts the unbalanced input to balanced output. The antenna is fabricated on a low cost glass epoxy FR4 substrate with dielectric constant = 4.4, substrate thickness = 1.6 mm, and loss tangent = 0.02. The overall size of the antenna is 84 mm×111 mm, which is 0.41λo×0.54λo at the center frequency of 1.45 GHz. Measured results show a bandwidth of 41.4% for VSWR≤2. A gain of 6.5 dBi±0.5 dB and front to back ratio (F/B) of better than 20 dB are achieved over the bandwidth. Measured results are in good agreement with the simulated ones. This antenna is useful for RFID, portable direction finding, spectrum monitoring systems, etc.
2. Kumar, G. and K. P. Ray, Broadband Microstrip Antennas, Artech House, USA, 2003.
3. Qian, Y., et al., "Microstrip-fed quasi-Yagi antenna with broadband characteristics," Electronics Letters, Vol. 34, No. 23, 2194-2196, 1998.
4. Kaneda, N., et al., "A broadband planar quasi-Yagi antenna," IEEE Transactions on Antennas and Propagation, Vol. 50, No. 8, 1158-1160, 2002.
5. Shiroma, G. S. and W. A. Shiroma, "A two-element L-band quasi-Yagi antenna array with omnidirectional coverage," IEEE Transactions on Antennas and Propagation, Vol. 55, No. 12, 3713-3716, 2007.
6. Ma, T. G., et al., "A modified quasi-Yagi antenna with a new compact microstrip-to-coplanar strip transition using artificial transmission lines," IEEE Transactions on Antennas and Propagation, Vol. 57, No. 8, 2469-2474, 2009.
7. Karbalaee, H., M. R. Salehifar, and S. Soleimany, Designing Yagi-Uda antenna fed by microstrip line and simulated by HFSS, 2012 6th International Conference on Application of Information and Communication Technologies (AICT), 1-5, Tbilisi, 2012.
8. Zheng, G., et al., "Simplified feed for modified printed Yagi antenna," Electronics Letters, Vol. 40, No. 8, 464-466, 2004.
9. Zheng, G., et al., Simplified feeding for a modified printed Yagi antenna, 2003 IEEE Antennas and Propagation Society International Symposium, Vol. 3, 934-937, Columbus, OH, USA, 2003.
10. Kan, H. K., et al., "Simple broadband planar CPW-fed quasi-Yagi antenna," IEEE Antennas and Wireless Propagation Letters, Vol. 6, 18-20, 2007.
11. Kan, H. K., et al., A simple broadband planar quasi-Yagi antenna, TENCON 2006 — 2006 IEEE Region 10 Conference, 1-3, Hong Kong, 2006.
12. Li, Z., et al., A quasi-Yagi microstrip antenna with simplified feeding structure, 2010 9th International Symposium on Antennas Propagation and EM Theory (ISAPE), 860-863, Guangzhou, 2010.
13. Sor, J., Y. Qian, and T. Itoh, "Coplanar waveguide fed quasi-Yagi antenna," Electronics Letters, Vol. 36, No. 1, 1-2, 2000.
14. Nguyen, P. T., A. Abbosh, and S. Crozier, "Wideband and compact quasi-Yagi antenna integrated with balun of microstrip to slotline transitions," Electronics Letters, Vol. 49, No. 2, 88-89, 2013.
15. Han, K., et al., "Broadband CPS-fed Yagi-Uda antenna," Electronics Letters, Vol. 45, No. 24, 1207-1209, 2009.
16. De Jean, G. R. and M. M. Tentzeris, "A new high-gain microstrip Yagi array antenna with a high front-to-back (F/B) ratio for WLAN and millimeter-wave applications," IEEE Transactions on Antennas and Propagation, Vol. 55, No. 2, 298-304, 2007.
17. Thai, T. T., G. R. De Jean, and M. M. Tentzeris, "Design and development of a novel compact soft-surface structure for the front-to-back ratio improvement and size reduction of a microstrip Yagi array antenna," IEEE Antennas and Wireless Propagation Letters, Vol. 7, 369-373, 2008.
18. Nikitin, P. V. and K. V. S. Rao, Compact Yagi antenna for handheld UHF RFID reader, 2010 IEEE Antennas and Propagation Society International Symposium, 1-4, Toronto, ON, 2010.
19. Huang, H.-C., J.-C. Lu, and P. Hsu, A simple planar high-directivity Yagi-Uda antenna with a concave parabolic reflector, 2010 International Workshop on Antenna Technology (iWAT), 1-4, Lisbon, 2010.
20. Huang, H. C., J. C. Lu, and P. Hsu, A planar Yagi-Uda antenna with a meandered driven dipole and a concave parabolic reflector, 2010 Asia-Pacific Microwave Conference, 995-998, Yokohama, 2010.
21. Huang, H. C., J. C. Lu, and P. Hsu, On the size reduction of planar Yagi-Uda antenna using parabolic reflector, 2015 Asia-Pacific Microwave Conference (APMC), 1-3, Nanjing, 2015.
22. Huang, E. and T. Chiu, "Printed Yagi antenna with multiple reflectors," Electronics Letters, Vol. 40, No. 19, 1165-1166, 2004.
23. Kan, H. K., et al., "Compact broadband coplanar waveguide-fed curved quasi-Yagi antenna," IET Microwaves, Antennas & Propagation, Vol. 1, No. 3, 572-574, 2007.
24. Pozar, D. M., "Microstrip antennas," Proceedings of the IEEE, Vol. 80, No. 1, 79-91, 1992.
25. Best, S. R., "On the resonant properties of the Koch fractal and other wire monopole antennas," IEEE Antennas and Wireless Propagation Letters, Vol. 1, No. 1, 74-76, 2002.
26. Tan, B. K., S. Withington, and G. Yassin, "A compact microstrip-fed planar dual-dipole antenna for broadband applications," IEEE Antennas and Wireless Propagation Letters, Vol. 15, 593-596, 2016.
27. Ta, S. X., H. Choo, and I. Park, "Wideband double-dipole Yagi-Uda antenna fed by a microstripslot coplanar stripline transition," Progress In Electromagnetics Research B, Vol. 44, 71-87, 2012.
28. Wu, J., et al., "Printed double-dipole antenna with high directivity using a new feeding structure," IET Microwaves, Antennas & Propagation, Vol. 8, No. 14, 1186-1191, 2014.
29. Yeo, J. and J. I. Lee, "Bandwidth enhancement of double-dipole quasi-Yagi antenna using stepped slotline structure," IEEE Antennas and Wireless Propagation Letters, Vol. 15, 694-697, 2016.
30., Barbano and N., "Log periodic Yagi-Uda array," IEEE Transactions on Antennas and Propagation, Vol. 14, No. 2, 235-238, 1966.
31. Carrel, R., The design of log-periodic dipole antennas, 1958 IRE International Convention Record, Vol. 9, 61-75, Mar., 1966.
32. Chen, G. Y. and J.-S. Sun, "A printed dipole antenna with microstrip tapered balun," Microwave Opt. Technol. Lett., Vol. 40, 344-346, 2004.
33. Kumar, H. and G. Kumar, Compact planar Yagi-Uda antenna with improved characteristics, 2017 11th European Conference on Antennas and Propagation (EUCAP), 2008-2012, Paris, 2017.