In this paper, a method to miniaturize a stepped open-slot antenna (SOSA) for ultra-wideband (UWB) applications is proposed. The antenna consists of a stepped open slot, J-shaped slots, and two strip directors. A broadband microstrip-to-slotline transition with circular stubs is applied to feed the antenna. J-shaped slots are inserted on the ground plane of the antenna to create a new resonance in the low-frequency region, thereby miniaturizing the size of the antenna. Finally, two strip directors are appended above the stepped open slot in order to increase the gain in the middle- and high-frequency regions, as well as to enhance input impedance matching in the high-frequency region. A prototype of the miniaturized SOSA is fabricated on an FR4 substrate with dimensions of 30 mm×32 mm. It shows a measured frequency band of 2.99-10.87 GHz for a voltage standing wave ratio < 2, which ensures UWB operation, and the measured gain range is 3.2-7.3 dBi in the band with a front-to-back ratio > 8.7 dB.
2. Denidni, T. A. and G. Augustin, Ultrawideband Antennas for Microwave Imaging Systems, Artech House, Norwood, 2014.
3. Balanis, C. A., Antenna Theory --- Analysis and Design, Wiley-Interscience, Hoboken, 2005.
4. Chen, D. and C. H. Cheng, "A novel compact ultra-wideband (UWB) wide slot antenna with via holes," Progress In Electromagnetics Research, Vol. 94, 343-349, 2009.
doi:10.2528/PIER09062306
5. Feng, H., L. Xu, P. Wang, and P. Gao, "Miniaturized UWB monopole-like slot antenna with low un-roundness of H-plane radiation patterns at high-frequency band," Progress In Electromagnetics Research Letters, Vol. 70, 107-113, 2017.
doi:10.2528/PIERL17071105
6. Gopikrishna, M., D. D. Krishna, C. K. Aanandan, P. Mohanan, and K. Vasudevan, "Design of a microstrip fed step slot antenna for UWB communication," Microw. Opt. Technol. Lett., Vol. 51, No. 4, 1126-1129, Apr. 2009.
doi:10.1002/mop.24262
7. Gopikrishna, M., D. D. Krishna, C. K. Aanandan, P. Mohanan, and K. Vasudevan, "Compact linear tapered slot antenna for UWB applications," Electron. Lett., Vol. 44, No. 20, 1174-1176, Sep. 2008.
doi:10.1049/el:20082269
8. Abbosh, A. M., "Miniaturized microstrip-fed tapered-slot antenna with ultrawideband performance," IEEE Antennas Wireless Propag. Lett., Vol. 8, 690-692, 2009.
doi:10.1109/LAWP.2009.2025613
9. Zhu, F., S. Gao, A. T. S. Ho, C. H. See, R. A. Abd-Alhameed, J. Li, and J. Xu, "Compact-size linearly tapered slot antenna for portable ultra-wideband imaging systems," Int. J. RF Microwave Comput. Aided Eng., Vol. 23, No. 3, 290-299, May 2013.
doi:10.1002/mmce.20673
10. Yeo, J. and J. I. Lee, "Design of compact stepped open slot Antenna for UWB applications," J. Korea Inst. Inf. Commun. Eng., Vol. 21, No. 1, 1-7, Jan. 2017.
doi:10.6109/jkiice.2017.21.1.1
11. Yeo, J., J. I. Lee, and Y. K. Cho, "Miniaturized stepped open slot antenna for UWB applications," 2018 IEEE International Symposium on Antennas and Propagation, 1-2, Boston, Massachusetts, 2018.
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