Show simple item record

dc.contributor.authorButler, Celia A.M.en_GB
dc.date.accessioned2012-06-19T07:41:39Zen_GB
dc.date.accessioned2013-03-21T10:28:15Z
dc.date.issued2012-05-04en_GB
dc.description.abstractMetamaterials are a class of artificial material, known to produce electromagnetic (EM) responses not found in nature due to their engineered subwavelength structure. In this thesis very thin subwavelength meshes are utilised to form layered metamaterials. The EM characteristics of the transmission and reflection response from these materials, including the polarisation converting behaviour, are explored to further understanding and develop structures to exploit and control the propagation of microwave radiation. Original experimental studies are presented across two sections; the first examines the response of stacks assembled from metallic meshes and dielectric plates; the second explores a rotated layered structure formed of square symmetric elements in a square subwavelength array that demonstrates chirality through evanescent coupling of the near fields. When metallic meshes are excited with EM radiation below the cut off frequency, only evanescently decaying fields are supported in the holes. By combining these subwavelength metallic meshes with dielectric plates in different arrangements, remarkably wide bands of high transmission and low reflection may be observed. The non-interacting resonant modes allow the response to be tuned through a suitable choice of the metallic mesh geometry and the properties of the dielectric. Further the low frequency band edge and the bandwidth are not dependent on the number of unit cells in the stack; but are dependent on the properties of the unit cell. The second section demonstrates ``evanescent handedness'' proposed as a new type of chirality. Two subwavelength square arrays of square elements are rotated with respect to one another. When the rotated arrays are positioned far from one another in the propagation direction, each acts as an effective medium layer. However when placed in close proximity the structure is shown to rotate the plane of polarisation of the incident radiation. All these mesh based structures share the property of producing an EM response that is tunable by design, allowing a structure to be tailored to a specific application.en_GB
dc.description.sponsorshipEPSRC Industrial CASE award, QinetiQen_GB
dc.identifier.citation"Microwave transmissivity of a metamaterial-dielectric stack", Celia A. M. Butler, James Parsons, J. Roy Sambles, Alastair. P. Hibbins, Peter A. Hobson, Applied Physics Letters, 95, 174101 (2009).en_GB
dc.identifier.citation"Circuit modeling of the transmissivity of stacked two-dimensional metallic meshes", Chandra S. R. Kaipa, Alexander B. Yakolev, Francisco Medina, Francisco Mesa, Celia A. M. Butler, and Alastair P. Hibbins, Optics Express, 18, 13, 13309-13320 (2010).en_GB
dc.identifier.citation"Metamaterial tunnel barrier gives broadband microwave transmission", Celia A. M. Butler, Ian R. Hooper, Peter A. Hobson, Alastair P. Hibbins, and J. Roy Sambles, Journal of Applied Physics, 109, 013104 (2011).en_GB
dc.identifier.grantnumberSH-04093en_GB
dc.identifier.urihttp://hdl.handle.net/10036/3596en_GB
dc.language.isoenen_GB
dc.publisherUniversity of Exeteren_GB
dc.subjectMicrowavesen_GB
dc.subjectMetamaterialsen_GB
dc.subjectMeshen_GB
dc.subjectElectromagneticen_GB
dc.subjectChiralen_GB
dc.titleThe Microwave Response of Square Mesh Metamaterialsen_GB
dc.typeThesis or dissertationen_GB
dc.date.available2012-06-19T07:41:39Zen_GB
dc.date.available2013-03-21T10:28:15Z
dc.contributor.advisorHibbins, Alastair P.en_GB
dc.contributor.advisorSambles, J. Royen_GB
dc.publisher.departmentPhysicsen_GB
dc.type.degreetitlePhD in Physicsen_GB
dc.type.qualificationlevelDoctoralen_GB
dc.type.qualificationnamePhDen_GB


Files in this item

This item appears in the following Collection(s)

Show simple item record