{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/78403"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/78403","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Characteristic mode theory for closely spaced dipole arrays","abstract":"Applications of antenna arrays, such as radar, benefit significantly from an array with wide operational bandwidth. In order to create these arrays, designers have traditionally relied on arraying relatively wideband antennas. Recently, planar arrays utilizing narrowband elements have been shown to exhibit good wideband behavior when the elements are spaced less than the typical half wavelength spacing used by designers. The reason behind this result is not clear. The phenomenon is investigated in this work through the lens of antenna characteristic modes. The modes of an array are calculated using the method of moments, and these modes are characterized by their radiative behavior. Additionally, the Q factor of these planar arrays is calculated using the Fourier transforms of the tangential fields at the aperture. In the process, the wideband behavior of these closely spaced arrays of dipoles is explained. These concepts are then translated to antenna design parameters such as element input impedance and array current distributions for beam scanning and sidelobe reduction. The modes are then calculated and interpreted for higher order dipole resonances to understand their behavior over a wide frequency band. Lastly, the modes of a dipole array with a backing ground plane are described. The result is a description of the physics of closely spaced arrays based on a set of orthogonal modes which allows antenna array designers to make informed design choices for wideband arrays before having to perform computationally expensive full-wave simulations on these electrically large structures.","abstract_html":"Applications of antenna arrays, such as radar, benefit significantly from an array with wide operational bandwidth. In order to create these arrays, designers have traditionally relied on arraying relatively wideband antennas. Recently, planar arrays utilizing narrowband elements have been shown to exhibit good wideband behavior when the elements are spaced less than the typical half wavelength spacing used by designers. The reason behind this result is not clear. The phenomenon is investigated in this work through the lens of antenna characteristic modes. The modes of an array are calculated using the method of moments, and these modes are characterized by their radiative behavior. Additionally, the Q factor of these planar arrays is calculated using the Fourier transforms of the tangential fields at the aperture. In the process, the wideband behavior of these closely spaced arrays of dipoles is explained. These concepts are then translated to antenna design parameters such as element input impedance and array current distributions for beam scanning and sidelobe reduction. The modes are then calculated and interpreted for higher order dipole resonances to understand their behavior over a wide frequency band. Lastly, the modes of a dipole array with a backing ground plane are described. The result is a description of the physics of closely spaced arrays based on a set of orthogonal modes which allows antenna array designers to make informed design choices for wideband arrays before having to perform computationally expensive full-wave simulations on these electrically large structures.","abstract_has_math":false,"creators":["King, Aaron J."],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Electrical & Computer Engr","degree_department":null,"school":null,"contributors":["Bernhard, Jennifer T.","Franke, Steven J.","Gong, Songbin","Wasserman, Daniel M."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-07-22T22:16:58Z","date_published":"2015-07-22T22:16:58Z","updated_at":"2026-07-22T22:26:11Z","subjects":["Antenna Arrays","Characteristic Mode Theory","Coupled Mode Theory"],"languages":["en"],"rights":["Copyright 2015 Aaron J. 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King"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/78403"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Applications of antenna arrays, such as radar, benefit significantly from an array with wide operational bandwidth. In order to create these arrays, designers have traditionally relied on arraying relatively wideband antennas. Recently, planar arrays utilizing narrowband elements have been shown to exhibit good wideband behavior when the elements are spaced less than the typical half wavelength spacing used by designers. The reason behind this result is not clear. The phenomenon is investigated in this work through the lens of antenna characteristic modes. The modes of an array are calculated using the method of moments, and these modes are characterized by their radiative behavior. Additionally, the Q factor of these planar arrays is calculated using the Fourier transforms of the tangential fields at the aperture. In the process, the wideband behavior of these closely spaced arrays of dipoles is explained. These concepts are then translated to antenna design parameters such as element input impedance and array current distributions for beam scanning and sidelobe reduction. The modes are then calculated and interpreted for higher order dipole resonances to understand their behavior over a wide frequency band. Lastly, the modes of a dipole array with a backing ground plane are described. The result is a description of the physics of closely spaced arrays based on a set of orthogonal modes which allows antenna array designers to make informed design choices for wideband arrays before having to perform computationally expensive full-wave simulations on these electrically large structures.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2015-07-22 without embargo terms","The student, Aaron King, accepted the attached license on 2015-04-16 at 14:12.","The student, Aaron King, submitted this Dissertation for approval on 2015-04-16 at 14:18.","This Dissertation was approved for publication on 2015-04-21 at 09:39.","DSpace SAF Submission Ingestion Package generated from Vireo submission #7900 on 2015-07-22 at 10:32:35","Made available in DSpace on 2015-07-22T22:16:58Z (GMT). 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Recently, planar arrays utilizing narrowband elements have been shown to exhibit good wideband behavior when the elements are spaced less than the typical half wavelength spacing used by designers. The reason behind this result is not clear. The phenomenon is investigated in this work through the lens of antenna characteristic modes. The modes of an array are calculated using the method of moments, and these modes are characterized by their radiative behavior. Additionally, the Q factor of these planar arrays is calculated using the Fourier transforms of the tangential fields at the aperture. In the process, the wideband behavior of these closely spaced arrays of dipoles is explained. These concepts are then translated to antenna design parameters such as element input impedance and array current distributions for beam scanning and sidelobe reduction. The modes are then calculated and interpreted for higher order dipole resonances to understand their behavior over a wide frequency band. Lastly, the modes of a dipole array with a backing ground plane are described. The result is a description of the physics of closely spaced arrays based on a set of orthogonal modes which allows antenna array designers to make informed design choices for wideband arrays before having to perform computationally expensive full-wave simulations on these electrically large structures.","Submission original under an indefinite embargo labeled 'Open Access'. The submission was exported from vireo on 2015-07-22 without embargo terms","The student, Aaron King, accepted the attached license on 2015-04-16 at 14:12.","The student, Aaron King, submitted this Dissertation for approval on 2015-04-16 at 14:18.","This Dissertation was approved for publication on 2015-04-21 at 09:39.","DSpace SAF Submission Ingestion Package generated from Vireo submission #7900 on 2015-07-22 at 10:32:35","Made available in DSpace on 2015-07-22T22:16:58Z (GMT). No. of bitstreams: 2 KING-DISSERTATION-2015.pdf: 16666358 bytes, checksum: adffc8daf3c973fd6790975696424e6b (MD5) LICENSE.txt: 4207 bytes, checksum: fef568561e9103bf871650736760ab88 (MD5) Previous issue date: 2015-04-21"],"dc:format":["application/pdf"],"dc:identifier":["http://hdl.handle.net/2142/78403"],"dc:language":["en"],"dc:rights":["Copyright 2015 Aaron J. King"],"dc:subject":["Antenna Arrays","Characteristic Mode Theory","Coupled Mode Theory"],"dc:title":["Characteristic mode theory for closely spaced dipole arrays"],"dc:type":["text"],"thesis:degree_discipline":["Electrical & Computer Engr"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:26:11Z"}