volume | PIER Journals

Abstract

Usually inactive or also known as thinned elements are used to simplify the array design complexity by turning off some of the active elements in uniformly filled arrays. Consequently, the far-field radiation characteristics such as sidelobe level, beamwidth, and directivity may be negatively changed if no optimizer is used. Further, these radiation characteristics may be unavoidably deteriorated when the main beam is scanned to new directions other than the referenced broadside direction. In this paper, an efficient optimization method based on the genetic algorithm and a dynamic deactivation method is proposed to randomly deactivate a number of array elements to minimize the peak sidelobe level and at the same time maintain the array directivity undistorted, while scanning the main beam. The deactivation method chooses optimally the suitable number of elements and their locations that need to be deactivated such that the resulting radiation characteristics positively change according to the specified cost function. Also, the proposed scanned array uses binary coefficients to activate and deactivate the array elements, thus, the feeding network of the proposed array is very simple, and it can be easily implemented in practice. Through extensive simulation results, we show that the proposed optimization method has good performance under wide range of scanned main beam directions. It is also found that the number of deactivation elements (i.e., the optimization variables) increases with larger scan angle.

1. Mohammed, Jafar Ramadhan, "An optimum side-lobe reduction method with weight perturbation," Journal of Computational Electronics, Vol. 18, No. 2, 705-711, 2019. Google Scholar

2. Abdulqader, Ahmed Jameel, Jafar Ramadhan Mohammed, and Raad H. Thaher, "Phase-only nulling with limited number of controllable elements," Progress In Electromagnetics Research C, Vol. 99, 167-178, 2020. Google Scholar

3. Mohammed, Jafar Ramadhan, "Phased sub-arrays pattern synthesis method with deep sidelobe reduction and narrow beam width," IETE Journal of Research, Vol. 69, No. 2, 1081-1087, Dec. 2020. Google Scholar

4. Mohammed, Jafar Ramadhan and Karam Mudhafar Younus, "Null steering implementation by controlling side-elements positions," International Journal of Microwave and Optical Technology, Vol. 16, No. 6, 568-575, Nov. 2021. Google Scholar

5. Keizer, Will P. M. N., "Low-sidelobe pattern synthesis using iterative fourier techniques coded in MATLAB [EM programmer's notebook]," IEEE Antennas and Propagation Magazine, Vol. 51, No. 2, 137-150, 2009. Google Scholar

6. Mohammed, Jafar Ramadhan, "A new antenna array pattern synthesis method with sidelobe control," Journal of Telecommunication, Electronic and Computer Engineering (JTEC), Vol. 10, No. 3, 31-36, Jul.-Sep. 2018. Google Scholar

7. Mohammed, J. R., "Optimal null steering method in uniformly excited equally spaced linear arrays by optimising two edge elements," Electronics Letters, Vol. 53, No. 13, 835-837, Jun. 2017. Google Scholar

8. Mohammed, Jafar Ramadhan, "Element selection for optimized multiwide nulls in almost uniformly excited arrays," IEEE Antennas and Wireless Propagation Letters, Vol. 17, No. 4, 629-632, Apr. 2018. Google Scholar

9. Mohammed, Jafar R., "A method for thinning useless elements in the planar antenna arrays," Progress In Electromagnetics Research Letters, Vol. 97, 105-113, Apr. 2021. Google Scholar

10. Haupt, Randy L., "Adaptively thinned arrays," IEEE Transactions on Antennas and Propagation, Vol. 63, No. 4, 1626-1632, Apr. 2015. Google Scholar

11. Mohammed, Jafar Ramadhan, "Beam-pattern control via thinned elements strategy in linear and planar phased arrays," Progress In Electromagnetics Research Letters, Vol. 111, 79-84, Jul. 2023.
doi:10.2528/PIERL23022403 Google Scholar

12. Mailloux, R. J., Phased Array Antenna Handbook, Artech House Publishers, 1999.

13. Zardi, Francesco, Payam Nayeri, Paolo Rocca, and Randy Haupt, "Artificial intelligence for adaptive and reconfigurable antenna arrays: A review," IEEE Antennas and Propagation Magazine, Vol. 63, No. 3, 28-38, Jun. 2021. Google Scholar

14. He, Yuanzhi and Changxu Wang, "Optimization design for sparse planar array in satellite communications," Electronics, Vol. 12, No. 8, 1763, 2023. Google Scholar

15. Shaker, Rana R. and Jafar R. Mohammed, "Obtaining feasible minimum side lobe level for narrow beam width using convex optimization in linear, planar, and random antenna arrays," Applied Computational Electromagnetics Society Journal, Vol. 37, No. 7, 811-816, Jul. 2022. Google Scholar

16. Jin, Nanbo and Yahya Rahmat-Samii, "Advances in particle swarm optimization for antenna designs: Real-number, binary, single-objective and multiobjective implementations," IEEE Transactions on Antennas and Propagation, Vol. 55, No. 3, 556-567, Mar. 2007. Google Scholar

17. Mohammed, Jafar Ramadhan, "Thinning a subset of selected elements for null steering using binary genetic algorithm," Progress In Electromagnetics Research M, Vol. 67, 147-155, 2018. Google Scholar

18. Zhao, Zhonghui, Huiling Zhao, Mingxuan Zheng, and Junjie Tang, "Real-time phase-only nulling based on deep neural network with robustness," IEEE Access, Vol. 7, 142287-142294, 2019. Google Scholar

19. Jain, Rajashree and G. S. Mani, "Dynamic thinning of antenna array using genetic algorithm," Progress In Electromagnetics Research B, Vol. 32, 1-20, 2011. Google Scholar

20. Singh, Urvinder and Tara Singh Kamal, "Optimal synthesis of thinned arrays using biogeography based optimization," Progress In Electromagnetics Research M, Vol. 24, 141-155, 2012. Google Scholar

Dr. Noor Waadullah Yaseen

Prof. Jafar Ramadhan Mohammed