Optimizations of antennas using heuristic algorithms supported by the multilevel fast multipole algorithm

Önol, Can
In this study, an optimization environment based on heuristic algorithms supported by the multilevel fast multipole algorithm (MLFMA) is presented for different antenna problems involving either excitation or geometry optimizations. The heuristic algorithms are implemented in-house by aiming more effective interactions between electromagnetic solvers and optimization algorithms, instead of black box interactions. Excitation optimizations of various array geometries for desired radiation characteristics are investigated in numerical experiments involving extremely large optimization spaces. Implemented heuristic algorithms are improved via alternative mechanisms and compared to available toolbox of MATLAB. In addition to excitation optimizations, we consider more challenging optimizations involving geometric modifications. In this context, two different types of pixel antennas are studied and optimized. Furthermore, the designs obtained via optimizations are fabricated in low cost setups based on commercial inkjet printers. Measurements on fabricated samples demonstrate the effectiveness of the optimizations, as well as the efficacy of the low-cost production mechanism that fully benefits from the advantages of inkjet printing. Finally, approximate forms of MLFMA are examined for dynamic accuracy control during the optimizations. Effects of using these approximate forms and possible strategies for employing them in order to increase the speed of the optimizations are discussed.


Optimizations of Patch Antenna Arrays Using Genetic Algorithms Supported by the Multilevel Fast Multipole Algorithm
Onol, Can; Ergül, Özgür Salih (2014-12-01)
We present optimizations of patch antenna arrays using genetic algorithms and highly accurate full-wave solutions of the corresponding radiation problems with the multilevel fast multipole algorithm (MLFMA). Arrays of finite extent are analyzed by using MLFMA, which accounts for all mutual couplings between array elements efficiently and accurately. Using the superposition principle, the number of solutions required for the optimization of an array is reduced to the number of array elements, without resorti...
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Onol, Can; Gokce, Ozer; Boyacı, Huseyın; Ergül, Özgür Salih (null; 2015-07-09)
We present optimizations of three-dimensional antenna arrays using heuristic techniques coupled with the multilevel fast multipole algorithm (MLFMA). Without resorting to any periodicity and infinity assumptions, antenna arrays are modeled with surface integral equations and simulated via MLFMA, which also enables the analysis of arrays with non-identical elements. Genetic algorithms and particle swarm optimization methods are employed on the complex data produced by MLFMA in phasor domain to find optimal s...
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Özaydın, Seval; Koç, Seyit Sencer; Tanık, Yalçın; Department of Electrical and Electronics Engineering (2003)
In this thesis, optimization of the geometry of non-uniform arrays for direction finding yielding unambiguous results is studied. A measure of similarity between the array response vectors is defined. In this measure, the effects of antenna array geometry, source placements and antenna gains are included as variable parameters. Then, assuming that the antenna gains are known and constant, constraints on the similarity function are developed and described to result in unambiguous configurations and maximum r...
Antenna Switch Optimizations Using Genetic Algorithms Accelerated With the Multilevel Fast Multipole Algorithm
Onol, Can; Karaosmanoglu, Bariscan; Ergül, Özgür Salih (2015-07-24)
We present antenna switch optimizations using an efficient mechanism based on genetic algorithms and the multi-level fast multipole algorithm (MLFMA). Genetic algorithms are used to determine switch states for desired radiation and input characteristics, while cost-function evaluations are performed efficiently via an MLFMA implementation with dynamic error control. MLFMA is integrated into the genetic algorithm by extracting common computations to be performed once per optimization. Iterative convergence r...
Cylindrical Microstrip Patch Array Modified Neural Multiple Source Tracking Algorithm
Caylar, Selcuk; Dural, Guelbin; Leblebicioğlu, Mehmet Kemal (2008-07-11)
In this study Cylindrical Microstrip Patch Array Modified Neural Multiple Source Tracking Algorithm (CMN-MUST) is proposed. CMN-MUST implements previously reported Modified Neural Multiple Source Tracking Algorithm (MN-MUST). CMN-MUST algorithm uses the advantage of directive pattern of microstrip patch elements by considering only a part of array elements for a chosen sector. This reduces neural network sizes and also improves the spatial filtering performance. The proposed algorithm improves MN-MUST algor...
Citation Formats
C. Önol, “Optimizations of antennas using heuristic algorithms supported by the multilevel fast multipole algorithm,” M.S. - Master of Science, Middle East Technical University, 2015.