This work is purposed to provide microstrip antennas for a CP-SAR system with low sidelobe, tilted beam, and circular polarization. This antenna is configured for the L-band (1.27 GHz) mounting on an Unmanned Aerial Vehicle (UAV). The proposed microstrip antenna consists of three-square radiating elements, due to the ease in fabrication. Meanwhile, the proximity structure has been adopted in the feeding network. The tilted beam was obtained by arranging the different phases for each element. On the other hand, a low sidelobe was achieved by managing the power distribution of each patch using the Chebyshev polynomial. The proposed antenna was precisely printed and examined in an anechoic chamber to verify the characteristics of the antenna such as polarization, sidelobe level, and beam direction. Based on the measurement results, the proposed antenna has a tilted beam and a low side lobe that meets the specifications of the CP-SAR system.
2. Tanase, M. A., et al., "Synthetic aperture radar sensitivity to forest changes: A simulations-based study for the Romanian forests," Sci. Total Environ., Vol. 689, 1104-1114, 2019.
3. Tetuko, J., et al., "Development of circularly polarized synthetic aperture radar on-board UAV JX-1," Int. J. Remote Sens., 4762-4765, 2017.
4. Schwegmann, C. P., W. Kleynhans, B. P. Salmon, L. W. Mdakane, and R. G. V. Meyer, "Very deep learning for ship discrimination in Synthetic Aperture Radar imagery," International Geoscience and Remote Sensing Symposium (IGARSS), 104-107, 2016.
5. Sumantyo, J. T. S. and K. V. Chet, "Development of circularly polarized synthetic aperture radar onboard UAV for earth diagnosis," Proceedings of the European Conference on Synthetic Aperture Radar, EUSAR, 2012.
6. Brookner, E., W. M. Hall, and R. H. Westlake, "Faraday loss for L-band radar and communications systems," IEEE Trans. Aerosp. Electron. Syst., Vol. 21, No. 4, 459-469, 1985.
7. Yahya, M. and Z. Awang, "Cross polarization ratio analysis of circular polarized patch antenna," Proc. - 2010 12th Int. Conf. Electromagn. Adv. Appl. ICEAA'10, 442-445, 2010.
8. Fukusako, T., "Broadband characterization of circularly polarized waveguide antennas using L-shaped probe," J. Electromagn. Eng. Sci., Vol. 17, No. 1, 1-8, 2017.
9. Rignot, E. J. M., "Effect of Faraday rotation on L-band interferometric and polarimetric synthetic-aperture radar data," IEEE Trans. Geosci. Remote Sens., 383-390, 2000.
10. Baharuddin, M., V. Wissan, J. Tetuko Sri Sumantyo, and H. Kuze, "Elliptical microstrip antenna for circularly polarized synthetic aperture radar," AEU - Int. J. Electron. Commun., Vol. 65, No. 1, 62-67, 2011.
11. Shookooh, B. R., A. Monajati, and H. Khodabakhshi, "Theory, design, and implementation of a new family of ultra-wideband metamaterial microstrip array antennas based on fractal and fibonacci geometric patterns," J. Electromagn. Eng. Sci., Vol. 20, No. 1, 53-63, 2020.
12. Yohandri, V. Wissan, I. Firmansyah, P. Rizki Akbar, J. T. Sri Sumantyo, and H. Kuze, "Development of circularly polarized array antenna for synthetic aperture radar sensor installed on UAV," Progress In Electromagnetics Research C, Vol. 19, 119-133, 2011.
13. Hussein, M., Yohandri, J. T. S. Sumantyo, and A. Yahia, "A low sidelobe level of circularly polarized microstrip array antenna for CP-SAR sensor," Journal of Electromagnetic Waves and Applications, Vol. 27, No. 15, 1931-1941, Oct. 2013.
14. Yohandri, J. T. Sri Sumantyo, and H. Kuze, "Circularly polarized array antennas for synthetic aperture radar," PIERS Proceedings, 1244-1247, Suzhou, China, Sep. 12-16, 2011.
15. Varshney, H. K., M. Kumar, A. K. Jaiswal, R. Saxena, and K. Jaiswal, "A survey on different feeding techniques of rectangular microstrip patch antenna," Int. J. Curr. Eng. Technol., Vol. 4, No. 3, 1418-1423, 2014.
16. Clay, A. C., S. C. Wooh, L. Azar, and J. Y. Wang, "Experimental study of phased array beam steering characteristics," J. Nondestruct. Eval., Vol. 18, 59-71, 1999.
17. Balanis, C. E., Antenna Theory: Analysis and Design, 3rd Ed., 1136, 2005.
18. Kim, J. O., W. S. Yoon, and S. M. Han, "Frequency-selective beamforming array antenna systems with frequency-dependent phase shifters," J. Electromagn. Eng. Sci., Vol. 19, No. 4, 259-265, 2019.
19. Lee, S. G. and J. H. Lee, "Calculating array patterns using an active element pattern method with ground edge effects," J. Electromagn. Eng. Sci., Vol. 18, No. 3, 175-181, 2018.
20. Lee, K. F. and K. F. Tong, "Microstrip patch antennas," Handbook of Antenna Technologies, 2016.
21. Verma, R. K., N. K. Saxena, and P. K. S. Pourush, "Effect of air-gap technique in bandwidth of microstrip patch array antenna," Int. J. Res. Publ. Eng. Technol. [IJRPET], Vol. 3, No. 6, 165-168, 2017.
22. Arora, A., A. Khemchandani, Y. Rawat, S. Singhai, and G. Chaitanya, "Comparative study of different feeding techniques for rectangular microstrip patch antenna," Int. J. Innov. Res. Electr. Electron. Instrum. Control Eng., Vol. 3, No. 5, 2-35, 2015.
23. Garg, R., P. Bhartia, I. Bahl, and A. Ittipiboon, Microstrip Antenna Design Handbook, 2001.
24. Gautam, A. K., P. Benjwal, and B. K. Kanaujia, "A compact square microstrip antenna for circular polarization," Microw. Opt. Technol. Lett., Vol. 54, No. 4, 897-900, 2012.
25. Rizki Akbar, P., J. T. S. Sumantyo, and H. Kuze, "CP-SAR UAV Development," International Archives of the Photogrammetry, Remote Sensing and Spatial Information Science, Vol. XXXVIII, Part 8, 203-208, 2010.
26. Bevelacqua, P. J. and C. Balanis, "Antenna arrays: Performance limits and geometry optimization,", 158 pages, Arizona State Univ., 2008.
27. Alieldin, A., Y. Huang, M. Stanley, and S. Joseph, "A circularly polarized circular antenna array for satellite TV reception," 2018 15th Eur. Radar Conf. EuRAD 2018, 505-508, 2018.
28. Huang, J., W. Lin, F. Qiu, C. Jiang, D. Lei, and Y. J. Guo, "A low profile, ultra-lightweight, high efficient circularly-polarized antenna array for Ku band satellite applications," IEEE Access, Vol. 5, 18356-18365, 2017.