One of the common ways to design large arrays is by designing a small subarray known as cluster and using it as a repeating element throughout a large array. In this paper, the genetic algorithm is used to optimize the clustered amplitude tapers such that the final array pattern has minimum grating lobes and controlled sidelobe level. The formulation of the synthesis problem includes the minimization of the excess magnitude of the grating lobes or peak sidelobes which are usually higher than a given allowable limit. Moreover, two clustered configurations based on increased/decreased number of elements per cluster around the array center are introduced. Correspondingly, their clustered sizes increase/decrease as they approach the center of the array. Simulation results show that the proposed method has capability to optimize clustered linear and planar arrays without noticeable appearance of undesirable grating lobes. The analysis for an array composed of 20 elements with clusters of different cluster sizes M = 10, 8, 5, 4 and different numbers of elements per cluster Ns = 2, 3, 4, 5 elements found that the complexity reductions were 50%, 60%, 75%, 80%; peak sidelobe levels were -29 dB, -23.6 dB, -21.3 dB, -19.15 dB; and the directivities were 25.53 dB, 25.64 dB, 26.33 dB, 26.32 dB, respectively.
2. Mohammed, J. R., "Obtaining wide steered nulls in linear array patterns by controlling the locations of two edge elements," AEU International Journal of Electronics and Communications, Vol. 101, 145-151, Mar. 2019.
doi:10.1016/j.aeue.2019.02.004
3. 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.
4. Holden, J. M., "Grating lobe minimization in sum and difference beam patterns," IEEE International Symposium on Antennas and Propagation Society, Vol. 1, 772-775, Jun. 22-27, 2003.
5. Haupt, R., "Reducing grating lobes due to subarray amplitude tapering," IEEE Transactions on Antennas and Propagation, Vol. 33, No. 8, 846-850, Aug. 1985.
doi:10.1109/TAP.1985.1143682
6. Brockett, T. J. and Y. Rahmat-Samii, "Subarray design diagnostics for the suppression of undesirable grating lobes," IEEE Transactions on Antennas and Propagation, Vol. 60, No. 3, 1373-1380, Mar. 2012.
doi:10.1109/TAP.2011.2180333
7. Jeong, T., J. Yun, K. Oh, J. Kim, D. W. Woo, and K. C. Hwang, "Shape and weighting optimization of a subarray for a mm-Wave phased array antenna," Appl. Sci., Vol. 11, 6803, 2021, https://doi.org/10.3390/app11156803.
doi:10.3390/app11156803
8. Nickel, U., "Subarray con gurations for digital beamforming with low sidelobes and adaptive interference suppression," Proceedings of IEEE International Conference on Radar, Alexandria, 714-719, USA, 1995.
doi:10.1109/RADAR.1995.522636
9. Tarran, C., M. Mitchell, and R. Howard, "Wideband phased array radar with digital adaptive beamforming," High Resolution Radar and Sonar (Ref. No. 1999/051), 1/1-1/7, IEE Colloquium, May 11, 1999.
10. 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 Transctions on Antennas and Propagtion, Vol. 57, No. 6, 1684-1691, Jun. 2009.
doi:10.1109/TAP.2009.2019914
11. Rocca, P., L. Manica, R. Azaro, and A. Massa, "A hybrid approach for the synthesis of sub-arrayed monopulse linear arrays," IEEE Transctions on Antennas and Propagtion, Vol. 57, No. 1, 280-283, Jan. 2009.
doi:10.1109/TAP.2008.2009776
12. Mailloux, R. J., S. G. Santarelli, T. M. Roberts, and D. Luu, "Irregular polyomino-shaped subarrays for space-based active arrays," International Journal of Antennas and Propagation, Vol. 2009, 1-9, 2009.
doi:10.1155/2009/956524
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. Haupt, R., "Optimized weighting of uniform subarrays of unequal sizes," IEEE Transctions on Antennas and Propagation, Vol. 55, No. 4, 1207-1210, 2007.
doi:10.1109/TAP.2007.893406
15. Mohammed, J. R., "A method for thinning useless elements in the planar antenna arrays," Progress In Electromagnetics Research Letters, Vol. 97, 105-113, 2021.
doi:10.2528/PIERL21022104
16. Keizer, W. P. M., "Linear array thinning using iterative FFT techniques," IEEE Transctions on Antennas and Propagation, Vol. 56, No. 8, 2757-2760, 2008.
doi:10.1109/TAP.2008.927580
17. Mohammed, J. R., "Thinning a subset of selected elements for null steering using binary genetic algorithm," Progress In Electromagnetics Research M, Vol. 67, 147-157, 2018.
doi:10.2528/PIERM18021604
18. Rodriguez, A., L. Landesa, J. L. Rodriguez, F. Obelleiro, F. Ares, and A. Garcia-Pino, "Pattern synthesis of array antennas with arbitrary elements by simulated annealing and adaptive array theory," Microwave and Optical Technology Letters, Vol. 20, No. 1, 48-50, Jan. 5, 1999.
doi:10.1002/(SICI)1098-2760(19990105)20:1<48::AID-MOP13>3.0.CO;2-P
19. Lopez, P. and J. A. Rodriguez, "Subarray weighting for the difference patterns of monopulse antennas: Joint optimization of subarray con gurations and weights," IEEE Transactions on Antennas and Propagation, Vol. 49, No. 11, 1606-1608, Nov. 2001.
doi:10.1109/8.964098
20. 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
21. Balanis, C. A., Antenna Theory, Analysis and Design, 4th Edition, Wiley, 2016.
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