Partitioning large planar antenna arrays into smaller subarrays reduces the system costs and gives many other advantages. In this article, symmetrical T-shaped tetromino subarrays are suggested to perform the partition process of the large planar arrays. Different structures of T-shaped tetromino subarrays have been obtained by simply rotating its orientation by multiple angles of 90 degrees such that the entire planar array aperture can be filled. Two array architectures based on different T-shaped tetrominoes are constructed. The amplitude weights of the designed subarrays are optimized by means of the genetic algorithm such that the resulting array patterns have low sidelobe level. In the first architecture, all the elements in the original array are divided into several subarrays based on three T-shape structures, while in the second architecture all the elements are combined into eight different T-shapes. To control the sidelobe level in the proposed T-shaped tetromino subarrays, a surface mask boundary function is included in the optimization process to find the optimum weights of the T-shaped subarrays. Simulation results showed that the sidelobes can be reduced to less than -20 dB in the first architecture, and less than -25 dB in the second architecture, in addition to a significant reduction in the complexity of the feeding network for each one. Moreover, detailed connections of the feeding network circuitry of the used T-shaped tetromino subarray structures are given for practical implementation.
1. Sayidmarie, K. and J. R. Mohammed, "Performance of a wide angle and wide band nulling method for phased arrays," Progress In Electromagnetics Research M, Vol. 33, 239-249, 2013. doi:10.2528/PIERM13100603
2. Sarkar, T. K. and R. J. Mailloux, A History of Phased Array Antennas, in History of Wireless, John Wiley & Sons, Inc., Hoboken, NJ, USA, 2006.
3. Mohammed, J. R., "Synthesizing sum and difference patterns with low complexity feeding network by sharing element excitations," International Journal of Antennas and Propagation, Vol. Article ID 2563901, 7 pages, 2017, 2017.
4. Nickel, U. R., "Properties of digital beamforming with subarrays," IEEE Aerosp. Electron. Syst. Mag., Vol. 20, 46, 2006.
5. Ahmed, J. A., R. M. Jafar, and H. T. Raad, "Unconventional and irregular clustered arrays," 1st International Ninevah Conference on Engineering and Technology (INCET2021), Vol. 1152, 012003, IOP publisher, 2021.
6. Jeong, T., J. Yun, K. Oh, J. Kim, D. W. Woo, and K. C. Hwang, "Shape and weighting optimization of a subarray for an mm-Wave phased array antenna," Appl. Sci., Vol. 11, 2021. doi:10.3390/app112412003
7. Mohammed, J. R., "Minimizing grating lobes in large arrays using clustered amplitude tapers," Progress In Electromagnetics Research C, Vol. 120, 93-103, 2022. doi:10.2528/PIERC22031706
8. Mailloux, R. J., "A low-sidelobe partially overlapped constrained feed network for time-delayed subarrays," IEEE Trans. Antennas Propag., Vol. 49, 280-291, 2001. doi:10.1109/8.914295
9. Haupt, R. L., "Optimized weighting of uniform subarrays of unequal sizes," IEEE Trans. Antennas Propag., Vol. 53, 1207-1210, 2007. doi:10.1109/TAP.2007.893406
10. Lee, H., S. Boo, G. Kim, and B. Lee, "Optimization of excitation magnitudes and phases for maximum efficiencies in a MISO wireless power transfer system," J. Electromagn. Eng. Sci., Vol. 20, 16-22, 2020. doi:10.26866/jees.2020.20.1.16
11. Manica, L., P. Rocca, and A. Massa, "Design of subarrayed linear and planar array antennas with SLL control based on an excitation matching approach," IEEE Trans. Antennas Propag., Vol. 57, 1684-1691, 2009. doi:10.1109/TAP.2009.2019914
12. Xiong, Z. Y., Z. H. Xu, S. W. Chen, and S. P. Xiao, "Subarray partition in array antenna based on the algorithm X," IEEE Antennas Wireless Propag. Lett., Vol. 12, 906-909, 2013. doi:10.1109/LAWP.2013.2272793
13. Abdulqader, A. J., J. R. Mohammed, and R. H. Thaher, "Antenna pattern optimization via clustered arrays," Progress In Electromagnetics Research M, Vol. 95, 177-187, 2020. doi:10.2528/PIERM20042307
14. Mohammed, J. R. and K. H. Sayidmarie, "Synthesizing asymmetric sidelobe pattern with steered nulling in non-uniformly excited linear arrays by controlling edge elements," International Journal of Antennas and Propagation, Vol. 2017, Article ID 9293031, 8 pages, 2017.
15. Mohammed, J. R. and K. H. Sayidmarie, "Sidelobe cancellation for uniformly excited planar array antennas by controlling the side elements," IEEE Antennas Wireless Propag. Lett., Vol. 13, 987-990, 2014. doi:10.1109/LAWP.2014.2325025
16. Mohammed, J. R., A. J. Abdulqader, and R. H. Thaher, "Array pattern recovery under amplitude excitation errors using clustered elements," Progress In Electromagnetics Research M, Vol. 98, 183-192, 2020. doi:10.2528/PIERM20101906
17. Raad, H. T., R. M. Jafar, and J. A. Ahmed, "Array radiation pattern recovery under random errors using clustered linear array," Journal of Engineering and Sustainable Development, 2021.
18. Yang, K., Y. Wang, and H. Tang, "A subarray design method for low sidelobe levels," Progress In Electromagnetics Research Letters, Vol. 89, 45-51, 2020. doi:10.2528/PIERL19110301
19. Mailloux, R. J., S. G. Santarelli, D. L. Roberts, and D. Luu, "Irregular polyomino-shaped subarrays for space-based active arrays," International Journal of Antennas and Propagation, Vol. 2009, Article ID 956524, 9 pages, 2009.