{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,27]],"date-time":"2026-01-27T13:52:31Z","timestamp":1769521951135,"version":"3.49.0"},"reference-count":20,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2021,11,22]],"date-time":"2021-11-22T00:00:00Z","timestamp":1637539200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Spanish Government, Ministerio de Ciencia e Innovaci\u00f3n, Secretar\u00eda General de Investigaci\u00f3n","award":["PID2020-112545RB-C52"],"award-info":[{"award-number":["PID2020-112545RB-C52"]}]},{"DOI":"10.13039\/501100010801","name":"Xunta de Galicia","doi-asserted-by":"publisher","award":["ED431C 2019\/26"],"award-info":[{"award-number":["ED431C 2019\/26"]}],"id":[{"id":"10.13039\/501100010801","id-type":"DOI","asserted-by":"publisher"}]},{"name":"atlantTTic Research Center and the European Regional Development Fund (ERDF)","award":["-"],"award-info":[{"award-number":["-"]}]},{"name":"FCT\/MCTES through national funds and when applicable co-funded EU funds","award":["UIDB\/EEA\/50008\/2021"],"award-info":[{"award-number":["UIDB\/EEA\/50008\/2021"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Electronics"],"abstract":"<jats:p>Due to the global growth in popularity of Fifth Generation (5G) cellular communications, the demand for shielding against it has risen for a variety of applications, mainly related to cybersecurity but also to isolation, calm areas and so on. This research paper aims to provide a suitable dual-band fractal FSS (Frequency Selective Surface) for the 5G lower band frequencies: 750 MHz and 3.5 GHz. The unit cell is in the shape of a bow tie, where each of the triangular parts are Sierpi\u0144ski triangles. One major addition to the unit cell is a central metal strip to make the manufacturing of the FSS more feasible and to tune the operation frequencies and bandwidths. As with each different stage of a fractal antenna, the different stages of the fractal FSS design behave differently. For this application, stage 2 is sufficient, as we are able to cover frequency bands among those included in the FR1 5G spectrum. Some equations were derived using linear regression in order to provide specific design tools for building an FSS. These equations have high accuracy and can be used to adapt the proposed design to other frequencies. Some other parameters, which are not represented in the aforementioned equations, can also be adjusted for minor tweaking of the final design. This design performs well except under large incidence angles. This should be taken into account when proposing the installation of a structure based on it. A good agreement between simulation and measurement results is observed.<\/jats:p>","DOI":"10.3390\/electronics10222880","type":"journal-article","created":{"date-parts":[[2021,11,23]],"date-time":"2021-11-23T02:55:17Z","timestamp":1637636117000},"page":"2880","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":17,"title":["Dual-Band Single-Layer Fractal Frequency Selective Surface for 5G Applications"],"prefix":"10.3390","volume":"10","author":[{"given":"Bram","family":"Decoster","sequence":"first","affiliation":[{"name":"Signal Theory and Communications Department\/atlanTTic, University of Vigo, 36310 Vigo, Spain"},{"name":"Department of Information Technology, Ghent University\/imec, 9000 Ghent, Belgium"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5053-0558","authenticated-orcid":false,"given":"Stephanie","family":"Maes","sequence":"additional","affiliation":[{"name":"Signal Theory and Communications Department\/atlanTTic, University of Vigo, 36310 Vigo, Spain"},{"name":"Department of Information Technology, Ghent University\/imec, 9000 Ghent, Belgium"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8391-1947","authenticated-orcid":false,"given":"I\u00f1igo","family":"Cui\u00f1as","sequence":"additional","affiliation":[{"name":"Signal Theory and Communications Department\/atlanTTic, University of Vigo, 36310 Vigo, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1881-681X","authenticated-orcid":false,"given":"Manuel","family":"Garc\u00eda S\u00e1nchez","sequence":"additional","affiliation":[{"name":"Signal Theory and Communications Department\/atlanTTic, University of Vigo, 36310 Vigo, Spain"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0297-7870","authenticated-orcid":false,"given":"Rafael","family":"Caldeirinha","sequence":"additional","affiliation":[{"name":"Polytechnic of Leiria and Instituto de Telecomunica\u00e7\u00f5es, 2411-901 Leiria, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4003-0098","authenticated-orcid":false,"given":"Jo","family":"Verhaevert","sequence":"additional","affiliation":[{"name":"Department of Information Technology, Ghent University\/imec, 9000 Ghent, Belgium"}]}],"member":"1968","published-online":{"date-parts":[[2021,11,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1201","DOI":"10.1109\/JSAC.2017.2692307","article-title":"5G: A Tutorial Overview of Standards, Trials, Challenges, Deployment, and Practice","volume":"35","author":"Shafi","year":"2017","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"127639","DOI":"10.1109\/ACCESS.2019.2939938","article-title":"5G Evolution: A View on 5G Cellular Technology Beyond 3GPP Release 15","volume":"7","author":"Ghosh","year":"2019","journal-title":"IEEE Access"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"42828","DOI":"10.1109\/ACCESS.2020.2977406","article-title":"5G is Real: Evaluating the Compliance of the 3GPP 5G New Radio System With the ITU IMT-2020 Requirements","volume":"8","author":"Henry","year":"2020","journal-title":"IEEE Access"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"132","DOI":"10.1109\/MCOM.2016.1500799CM","article-title":"The METIS 5G System Concept: Meeting the 5G Requirements","volume":"54","author":"Tullberg","year":"2016","journal-title":"IEEE Commun. Mag."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"27","DOI":"10.1109\/MNET.2014.6963801","article-title":"Challenges in 5G: How to Empower SON with Big Data for Enabling 5G","volume":"28","author":"Imran","year":"2014","journal-title":"IEEE Netw."},{"key":"ref_6","unstructured":"(2021, November 17). South Korea Wraps 5G Auction for 3.5, 28 GHz. Available online: https:\/\/www.fiercewireless.com\/wireless\/south-korea-wraps-5g-auction-for-3-5-28-ghz."},{"key":"ref_7","unstructured":"(2021, November 17). A Guide to 5G Spectrum Auctions in Western Europe: Nordic Edition. Available online: https:\/\/blog.telegeography.com\/a-guide-to-5g-spectrum-auctions-in-western-europe-nordic-edition."},{"key":"ref_8","unstructured":"5G Spectrum (2020). GSMA Public Policy Position, GSMA Head Office."},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Munk, B.A. (2000). Frequency Selective Surfaces: Theory and Design, Wiley.","DOI":"10.1002\/0471723770"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"110","DOI":"10.1109\/MAP.2018.2870583","article-title":"A Review of Manufacturing Materials and Production Methods for Frequency-Selective Structures [Wireless Corner]","volume":"60","author":"Ferreira","year":"2018","journal-title":"IEEE Antennas Propag. Mag."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"1097","DOI":"10.1109\/8.876329","article-title":"Fractal FSS: A Novel Dual-Band Frequency Selective Surface","volume":"48","author":"Romeu","year":"2000","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_12","unstructured":"CST Microwave Studio (2021, November 17). Dassault Syst\u00e8me, V\u00e9lizy-Villacoublay Cedex. Available online: https:\/\/www.3ds.com\/products-services\/simulia\/products\/cst-studio-suite\/."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"202","DOI":"10.1109\/MAP.2013.6735515","article-title":"Extraction of Material Parameters for Metamaterials Using a Full-Wave Simulator [Education Column]","volume":"55","author":"Numan","year":"2013","journal-title":"IEEE Antennas Propag. Mag."},{"key":"ref_14","unstructured":"Dassault Syst\u00e8mes (2019). CST Studio Suite Help, Dassault Syst\u00e8mes."},{"key":"ref_15","unstructured":"Mandelbrot, B.B. (1982). The Fractal Geometry of Nature, W.H.Freeman & Co Ltd."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1278","DOI":"10.1109\/PROC.1986.13617","article-title":"The Fractal Random Array","volume":"74","author":"Kim","year":"1986","journal-title":"Proc. IEEE"},{"key":"ref_17","unstructured":"Felber, P. (2000). Fractal Antennas, Illinois Institute of Technology. Technical Report."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"38","DOI":"10.1109\/MAP.2003.1189650","article-title":"An Overview of Fractal Antenna Engineering Research","volume":"45","author":"Werner","year":"2003","journal-title":"IEEE Antennas Propag. Mag."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Ghosh, B., Sinha, S.N., and Kartikeyan, M.V. (2014). Fractal Apertures in Waveguides, Conducting Screens and Cavities, Springer International Publishing.","DOI":"10.1007\/978-3-319-06535-9"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Munk, B.A. (2003). Finite Antenna Arrays and FSS, John Wiley & Sons, Inc.","DOI":"10.1002\/0471457531"}],"container-title":["Electronics"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2079-9292\/10\/22\/2880\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T07:34:20Z","timestamp":1760168060000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2079-9292\/10\/22\/2880"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,11,22]]},"references-count":20,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2021,11]]}},"alternative-id":["electronics10222880"],"URL":"https:\/\/doi.org\/10.3390\/electronics10222880","relation":{},"ISSN":["2079-9292"],"issn-type":[{"value":"2079-9292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,11,22]]}}}