volume | PIER Journals

Abstract

A compact unidirectional slot antenna with front to back ratio (FBR) enhancement is proposed. The antenna consists of a novel compact slot driven antenna, a stepped reflector and a vertical balun from a microstrip to a parallel strip line. Better FBRs are obtained by optimizing the stepped reflector. Impedance bandwidths are enhanced by applying the balun and a pair of microstrip stub etched on the opposite side of the slot. Then, the antenna is manufactured and measured. Measured results show that the proposed antenna has a bandwidth of 76% (1.53-3.41 GHz) for VSWR ≤ 1.5. In addition, from 1.7 to 3.2 GHz, the antenna gains are higher than 8.6 dBi, and the FBRs are greater than 22 dB. Good agreement between the simulated and measured results is obtained. All above indicates that the proposed antenna can be widely used in wireless communications.

1. Nakano, H. and J. Yamauchi, "Printed slot and wire antenna: A review," Proceedings of the IEEE, Vol. 100, No. 7, 2158-2168, Jul. 2012.
doi:10.1109/JPROC.2011.2180269 Google Scholar

2. Yun, S., D.-Y. Kim, and S. Nam, "Bandwidth enhancement of cavity-backed slot antenna using a via-hole above the slot," IEEE Antennas Wireless Propag. Lett., Vol. 11, 1092-1095, 2012. Google Scholar

3. Chair, R., A. A. Kishk, K. F. Lee, and C. E. Smith, "Unidirectional wideband slot aperture antennas," IEEE Antennas and Propagation Society International Symposium (APSURSI), 1875-1878, 2004. Google Scholar

4. Wang, C. J. and Y. Dai, "Enhancement of pattern directivity for the open slot antenna by utilizing array topology," Microwave Opt. Technol. Lett., Vol. 54, No. 5, 1273-1277, Mar. 2012.
doi:10.1002/mop.26782 Google Scholar

5. Chen, W. Q., G. F. Ding, B. H. Li, and X. F. Li, "Design and simulation of broadband unidirectional CPW-fed rectangular slot antennas," IEEE International Conference on Microwave, Antennas, Propagation and EMC Technologies for Wireless Communications (MAPE), 632-635, 2007. Google Scholar

6. Chaimool, S., P. Akkaraekthalin, and M. Krairiksh, "Reflector shape optimization for wideband uni-directional of CPW-fed slot antenna," International Symposium on Antennas and Propagation, (ISAP), 1206-1209, 2007. Google Scholar

7. Zhang, Z. Y., S.-L. Zuo, and J. Y. Zhao, "Wideband folded bowtie antenna with Γ-shaped strip feed and tuning stubs," Microwave Opt. Technol. Lett., Vol. 55, No. 9, 2145-2149, Jun. 2013.
doi:10.1002/mop.27754 Google Scholar

8. Govindanarayanan, I. and N. Rangaswamy, "Asymmetric folded dipole antenna with high front to back ratio for LTE base stations," IEEE Antennas Wireless Propag. Lett., Vol. 15, 869-872, 2016.
doi:10.1109/LAWP.2015.2478197 Google Scholar

9. Wang, Z. D., X. L. Liu, Y. Z. Yin, and J. J. Wu, "Dual-element folded dipole design for broadband multilayered Yagi antenna for 2G/3G/LTE applications," Electron Lett., Vol. 50, No. 4, 242-244, Feb. 2014.
doi:10.1049/el.2013.4146 Google Scholar

10. Fei, P., Y. H. Qi, and Y. C. Jiao, "Design of a wideband dual-element slot loop antenna array with adjustable back-reflector," IEEE Antennas Wireless Propag. Lett., Vol. 11, 1014-1017, 2012. Google Scholar

11. Gao, X. Y., Y. H. Qi, and Y. C. Jiao, "Design of multiplate back-reflector for a wideband slot antenna," IEEE Antennas Wireless Propag. Lett., Vol. 12, 773-776, 2013.
doi:10.1109/LAWP.2013.2270945 Google Scholar

Dr. Liang Lu

Dr. Yong-Chang Jiao

Professor Zibin Weng

Dr. Lei Zhou