Date of Award
4-2013
Access Type
Thesis - Open Access
Degree Name
Master of Science in Electrical & Computer Engineering
Department
Electrical, Computer, Software, and Systems Engineering
Committee Chair
Dr. William Barott
First Committee Member
Dr. Richard Stansbury
Second Committee Member
Dr. Timothy Wilson
Abstract
Acoustic phased arrays with inter-element spacings of greater than one half-wavelength will produce grating lobes that decrease the usefulness of the array. With many array configurations, the near-field and far-field character of these lobes is significantly different -- an optimization of the array configuration to reduce grating lobes in the far-field can have little bearing on the performance of the array in the near-field.
The focus of this thesis is the reduction of grating lobes in the near-field by iterative optimization. Genetic algorithms are employed to choose inter-element spacings which are able to reduce the magnitude of grating lobes at select distances in the near-field. The genetic algorithm produced configurations that are theoretically able to suppress grating lobes in the near-field.
In order to verify the efficacy of these configurations, a hardware test platform was constructed. The platform permits largely automated evaluation of the near-field character of arbitrary array configurations. Using the test platform, several of the arrangements were constructed and evaluated. The results of these evaluations confirm that it is possible to reduce the grating lobes of sparse phased arrays in the near-field.
Scholarly Commons Citation
Rudolph, Dylan, "Reduction of Near-Field Grating Lobes in Sparse Acoustic Phased Arrays" (2013). Doctoral Dissertations and Master's Theses. 125.
https://commons.erau.edu/edt/125
