A filtering antenna based on a dumbbell-shaped resonator is proposed, fabricated and measured. A Γ-shaped antenna and the proposed dumbbell-shaped resonator are used and integrated to be a filtering antenna. The Γ-shaped antenna which acts as a radiator is excited by a coupled line. Measured results show that the filtering antenna achieves an impedance bandwidth of 6.7% at a reflection coefficient |S11| < -10dB and has a gain of 1.35 dBi. Moreover, a radiation zero occurs at 3.1GHz. Compared with the characteristics of fundamental Γ-shaped antenna, the design of the dumbbell resonator has little impact on antenna's radiation patterns. In addition, to explain the mechanism of filtering antenna, the analysis of surface current distribution on patch is given. The size of filtering antenna is 0.33λ0×0.17λ0 (λ0 is the free-space wavelength at 2.45 GHz). Compared to other recent works, a simpler structure and more compact size are the key features. Owing to the operating bandwidth and the characteristic of filtering, the proposed antenna can be used in modern wireless communications systems.
1. Wang, Z.-Y. and C.-P. Zhang, "A planar UWB antenna with triple-notched bands," Progress In Electromagnetics Research Letters, Vol. 52, 99-104, 2015. doi:10.2528/PIERL15010402
2. Ding, C., J. Li, F. Wei, and X. Shi, "Compact bandpass filter based on parallel-coupled lines and quasi-lumped structure," Frequenz, Vol. 70, 11-15, 2016. doi:10.1515/freq-2015-0056
3. Wu, C.-M. and Y.-H. Liu, "An ultra-wideband twin-patch monopole antenna with band-rejection characteristic," Progress In Electromagnetics Research Letters, Vol. 53, 77-82, 2015. doi:10.2528/PIERL15030107
4. Chuang, C.-T. and S.-J. Chung, "A compact printed filtering antenna using a ground-intruded coupled line resonator," IEEE Transactions on Antennnas and Propagation, Vol. 59, No. 10, 2011. doi:10.1109/TAP.2011.2163777
5. Chen, L. and Y.-L. Luo, "Compact filtering antenna using CRLH resonator and defected ground structure," Electronics Letters, Vol. 50, No. 21, 1496-1498, 2014. doi:10.1049/el.2014.2703
6. Wu, W.-J., Y.-Z. Yin, S.-L. Zuo, Z.-Y. Zhang, and J.-J. Xie, "A new compact filter-antenna for modern wireless communication systems," IEEE Antennnas and Wireless Propagation Letters, Vol. 10, 1131-1134, 2011.
7. Wong, S.W., T. G. Huang, C. X. Mao, Z. N. Chen, and Q. X. Chu, "Planar filtering ultra-wideband (UWB) antenna with shorting pins," IEEE Transactions on Antennas and Propagation, Vol. 61, No. 2, 948-952, 2013. doi:10.1109/TAP.2012.2223438
8. Chen, X., F. Zhao, L. Yan, and W. Zhang, "A compact filtering antenna with flat gain response within the passband," IEEE Antennnas and Wireless Propagation Letters, Vol. 12, 857-860, 2013. doi:10.1109/LAWP.2013.2271972
9. Hsieh, C.-Y., C.-H. Wu, and T.-G. Ma, "A compact dual-band filtering patch antennausing step impedance resonators," IEEE Antennnas and Wireless Propagation Letters, Vol. 14, 1056-1059, 2015. doi:10.1109/LAWP.2015.2390033
10. Wu, P.-C., L. Chen, and Y.-L. Luo, "Miniaturised wideband filtering antenna by employing CRLH-TL and simplified feeding structure," Electronics Letters, Vol. 51, No. 7, 548-550, 2015. doi:10.1049/el.2015.0329
11. Duan, W., X. Y. Zhang, Y.-M. Pan, J.-X. Xu, and Q. Xue, "Dual-polarized filtering antenna with high selectivity and low cross polarization," IEEE Transactions on Antennas and Propagation, Vol. 64, No. 10, 4188-4196, 2016. doi:10.1109/TAP.2016.2594818
12. Lin, C.-K. and S.-J. Chung, "A compact filtering microstrip antenna with quasi-elliptic broadside antenna gain response," IEEE Antennas and Wireless Propagation Letters, Vol. 10, 381-384, 2011.
13. Hsieh, C.-Y., C.-H. Wu, and T.-G. Ma, "A compact dual-band filtering patch antenna using step impedance resonators," IEEE Antennas and Wireless Propagation Letters, Vol. 14, 1056-1059, 2015. doi:10.1109/LAWP.2015.2390033
14. Jiang, Z. H. and D. H. Werner, "A compact, wideband circularly polarized co-designed filtering antenna and its application for wearable devices with low SAR," IEEE Transactions on Antennas and Propagation, Vol. 63, No. 9, 3808-3818, 2015. doi:10.1109/TAP.2015.2452942
15. Zhang, X. Y., W. Duan, and Y.-M. Pan, "High-gain filtering patch antenna without extra circuit," IEEE Transactions on Antennas and Propagation, Vol. 63, No. 12, 5883-5888, 2015. doi:10.1109/TAP.2015.2481484
16. Koley, S. and D. Mitra, "A planar microstrip-fed tri-band filtering antenna for WLAN/WiMAX applications," Microwave and Optical Technology Letters, Vol. 57, No. 1, 233-237, 2015. doi:10.1002/mop.28813
17. Soltanpour, M. and M. M. Fakharian, "Compact filtering slot antenna with frequency agility for Wi-Fi/LTE mobile applications," Electronics Letters, Vol. 52, No. 7, 491-492, 2016. doi:10.1049/el.2015.3198
18. Mandal, M. K., Z. N. Chen, and X. Qing, "Compact ultra-wideband filtering antennas on low temperature co-fired ceramic substrate," Asia Pacific Microwave Conference, 2009.
19. Zuo, J. H., X. W. Chen, G. R. Han, L. Li, and W. M. Zhang, "An integrated approach to RF antenna-filter co-design," IEEE Antennas and Wireless Propagation Letters, Vol. 8, 141-144, 2009.
20. Fakharian, M. M., P. Rezaei, A. A. Orouji, and M. Soltanpur, "A wideband and reconfigurable filtering slot antenna," IEEE Antennas and Wireless Propagation Letters, Vol. 15, 2016.