A Varactor-Loaded Spoof-Plasmonic Reconfigurable Intelligent Surface Unit Cell for Wideband Phase and Wavefront Control

A Varactor-Loaded Spoof-Plasmonic Reconfigurable Intelligent Surface Unit Cell for Wideband Phase and Wavefront Control | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article A Varactor-Loaded Spoof-Plasmonic Reconfigurable Intelligent Surface Unit Cell for Wideband Phase and Wavefront Control Qurat ul Ain, Rameez Asif, Xiaodong Yang, Nan Zhao, Syed Aziz Shah This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8581195/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Reconfigurable intelligent surfaces (RIS) provide a compact and low-loss platform for controlling electromagnetic phase responses. This study investigates spoof plasmonic, varactor-loaded RIS unit cells as an approach for achieving continuous and broadband phase tunability within a simple and scalable architecture. A varactor-diode-loaded spoof surface plasmon polariton (SSPP) unit cell is designed for wideband reconfigurable operation in sub-5.9 GHz wireless sensing and communication systems. The proposed multilayer structure incorporates bias-controlled varactors at regions of strong electromagnetic field confinement within a spoof plasmonic cavity, enabling a continuous 180° phase tuning with reflection loss below − 10 dB over the 2–11.85 GHz frequency range. The unit cell exhibits a compact normalized footprint of 0.20λ₀ × 0.20λ₀ and maintains a |Γ| variation below 0.4 dB across four hybrid bias states, indicating nearly constant reflection magnitude and consistent field confinement under reconfiguration. These characteristics demonstrate broadband phase reconfigurability and support the applicability of the proposed RIS unit cell for electromagnetic wavefront manipulation in wireless sensing and channel control. Physical sciences/Engineering Physical sciences/Optics and photonics Physical sciences/Physics Full Text Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-8581195","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":590056878,"identity":"907b143f-3237-432b-921e-3901900d6106","order_by":0,"name":"Qurat ul Ain","email":"","orcid":"","institution":"Xidian University","correspondingAuthor":false,"prefix":"","firstName":"Qurat","middleName":"ul","lastName":"Ain","suffix":""},{"id":590056879,"identity":"fa31a129-d528-4090-aab9-7f64a17d8301","order_by":1,"name":"Rameez Asif","email":"data:image/png;base64,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","orcid":"","institution":"University of Greater Manchester","correspondingAuthor":true,"prefix":"","firstName":"Rameez","middleName":"","lastName":"Asif","suffix":""},{"id":590056880,"identity":"64c41e47-ecb4-499a-84e2-59ad8b954d56","order_by":2,"name":"Xiaodong Yang","email":"","orcid":"","institution":"Xidian University","correspondingAuthor":false,"prefix":"","firstName":"Xiaodong","middleName":"","lastName":"Yang","suffix":""},{"id":590056881,"identity":"2968ac84-13cb-4ce8-87d7-103615097a98","order_by":3,"name":"Nan Zhao","email":"","orcid":"","institution":"Xidian University","correspondingAuthor":false,"prefix":"","firstName":"Nan","middleName":"","lastName":"Zhao","suffix":""},{"id":590056882,"identity":"801266cd-0974-4f1a-9063-3edad1c6bbb0","order_by":4,"name":"Syed Aziz Shah","email":"","orcid":"","institution":"Coventry University","correspondingAuthor":false,"prefix":"","firstName":"Syed","middleName":"Aziz","lastName":"Shah","suffix":""}],"badges":[],"createdAt":"2026-01-12 11:38:19","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8581195/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8581195/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":102747092,"identity":"9ab10731-cd57-4603-bdfc-b543a95497b7","added_by":"auto","created_at":"2026-02-16 09:03:48","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1006774,"visible":true,"origin":"","legend":"","description":"","filename":"Manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8581195/v1_covered_80c2b7be-697e-46ef-82f3-6a48c49224e5.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"A Varactor-Loaded Spoof-Plasmonic Reconfigurable Intelligent Surface Unit Cell for Wideband Phase and Wavefront Control","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-8581195/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8581195/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eReconfigurable intelligent surfaces (RIS) provide a compact and low-loss platform for controlling electromagnetic phase responses. This study investigates spoof plasmonic, varactor-loaded RIS unit cells as an approach for achieving continuous and broadband phase tunability within a simple and scalable architecture. A varactor-diode-loaded spoof surface plasmon polariton (SSPP) unit cell is designed for wideband reconfigurable operation in sub-5.9 GHz wireless sensing and communication systems. The proposed multilayer structure incorporates bias-controlled varactors at regions of strong electromagnetic field confinement within a spoof plasmonic cavity, enabling a continuous 180\u0026deg; phase tuning with reflection loss below \u0026minus;\u0026thinsp;10 dB over the 2\u0026ndash;11.85 GHz frequency range. The unit cell exhibits a compact normalized footprint of 0.20λ₀ \u0026times; 0.20λ₀ and maintains a |Γ| variation below 0.4 dB across four hybrid bias states, indicating nearly constant reflection magnitude and consistent field confinement under reconfiguration. These characteristics demonstrate broadband phase reconfigurability and support the applicability of the proposed RIS unit cell for electromagnetic wavefront manipulation in wireless sensing and channel control.\u003c/p\u003e","manuscriptTitle":"A Varactor-Loaded Spoof-Plasmonic Reconfigurable Intelligent Surface Unit Cell for Wideband Phase and Wavefront Control","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-13 04:06:12","doi":"10.21203/rs.3.rs-8581195/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"ca19e945-cc12-4996-afe0-89177dd3ced7","owner":[],"postedDate":"February 13th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":62849172,"name":"Physical sciences/Engineering"},{"id":62849173,"name":"Physical sciences/Optics and photonics"},{"id":62849174,"name":"Physical sciences/Physics"}],"tags":[],"updatedAt":"2026-02-13T04:06:13+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-13 04:06:12","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8581195","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8581195","identity":"rs-8581195","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}