{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T01:10:26Z","timestamp":1760231426819,"version":"build-2065373602"},"reference-count":30,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2022,9,20]],"date-time":"2022-09-20T00:00:00Z","timestamp":1663632000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Iranian National Science Foundation (INSF)","award":["4003152"],"award-info":[{"award-number":["4003152"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This paper deals with the design and fabrication of an unpretentious (single-layer, without any lump element) broadband (97%, 11.3\u201332.3 GHz) radar cross-section reduction (RCSR) modulated surface (MS). The proposed structure uses sinusoidal modulation gap sizes between square patches within square unit cells to form a phase gradient that plays an effective role in improving the RCSR bandwidth. An MS with dimensions of 250 \u00d7 250 mm2, consisting of 40 \u00d7 40 unit cells with a period of 6 mm printed on a RO4003C (lossy) substrate of 0.06\u03bbLF (\u03bbLF being the wavelength at the lower frequency) thickness, has been prototyped. The MS has square patch (SP) unit cells with seven different gap sizes. A genetic algorithm (GA)-based fine-tuning has been implemented to further increase the performances of the structure. Measurements on it have been conducted considering both mono- and bi-static arrangements and for oblique incidences for both TM and TE polarization tests. A good agreement between simulation and measurement results proves the validity of the design criteria.<\/jats:p>","DOI":"10.3390\/s22197108","type":"journal-article","created":{"date-parts":[[2022,9,21]],"date-time":"2022-09-21T00:08:09Z","timestamp":1663718889000},"page":"7108","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":10,"title":["Wideband RCS Reduction by Single-Layer Phase Gradient Modulated Surface"],"prefix":"10.3390","volume":"22","author":[{"given":"Yousef","family":"Azizi","sequence":"first","affiliation":[{"name":"Department of Electrical Engineering, Iran University of Science & Technology, Tehran 1684613114, Iran"}]},{"given":"Mohammad","family":"Soleimani","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Iran University of Science & Technology, Tehran 1684613114, Iran"}]},{"given":"Seyed-Hasan","family":"Sedighy","sequence":"additional","affiliation":[{"name":"School of Advanced Technologies, Iran University of Science & Technology, Tehran 1684613114, Iran"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0946-9561","authenticated-orcid":false,"given":"Ladislau","family":"Matekovits","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, Politecnico di Torino, 10129 Turin, Italy"},{"name":"Istituto di Elettronica e di Ingegneria dell\u2019Informazione e delle Telecomunicazioni, National Research Council of Italy, 10129 Turin, Italy"},{"name":"Department of Measurements and Optical Electronics, Politehnica University Timi\u015foara, 300006 Timi\u015foara, Romania"}]}],"member":"1968","published-online":{"date-parts":[[2022,9,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1109\/LWC.2019.2948632","article-title":"Cascaded Channel Estimation for Large Intelligent Metasurface Assisted Massive MIMO","volume":"9","author":"He","year":"2019","journal-title":"IEEE Wirel. Commun. Lett."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"426","DOI":"10.1038\/nmat3292","article-title":"Gradient-index meta-surfaces as a bridge linking propagating waves and surface waves","volume":"11","author":"Sun","year":"2012","journal-title":"Nat. Mater."},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Wang, J., Qu, S., Ma, H., Chen, H., Feng, M., Li, Y., and Zhang, J. (2014, January 26\u201329). Manipulating the reflection of Electromagnetic waves using reflective metasurface. Proceedings of the 3rd Asia-Pacific Conference on Antenna and Propagation (APCAP), Harbin, China.","DOI":"10.1109\/APCAP.2014.6992581"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"2636","DOI":"10.1109\/TAP.2015.2414440","article-title":"Checkerboard EBG Surfaces for Wideband Radar Cross Section Reduction","volume":"63","author":"Chen","year":"2015","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1049\/el.2015.3515","article-title":"Wideband radar cross-section reduction by AMC","volume":"52","author":"Esmaeli","year":"2016","journal-title":"Electron. Lett."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2604","DOI":"10.1109\/TAP.2019.2891657","article-title":"Design of Checkerboard AMC Structure for Wideband RCS Reduction","volume":"67","author":"Sang","year":"2019","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"285304","DOI":"10.1088\/1361-6463\/aac986","article-title":"Ultra wide band radar cross section reduction using multilayer artificial magnetic conductor metasurface","volume":"51","author":"Ameri","year":"2018","journal-title":"J. Phys. D Appl. Phys."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"2706","DOI":"10.1364\/OME.7.002706","article-title":"Shared aperture metasurface with ultra-wideband and wide-angle low-scattering performance","volume":"7","author":"Zheng","year":"2017","journal-title":"Opt. Mater. Express"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"11437","DOI":"10.1038\/s41598-017-11714-y","article-title":"Pixelated Checkerboard Metasurface for Ultra-Wideband Radar Cross Section Reduction","volume":"7","author":"Nayyeri","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"035027","DOI":"10.1063\/1.5013106","article-title":"Metasurface base on uneven layered fractal elements for ultra-wideband RCS reduction","volume":"8","author":"Su","year":"2018","journal-title":"AIP Adv."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"044088","DOI":"10.1103\/PhysRevApplied.11.044088","article-title":"Ultra-wideband radar cross section reduction by a metasurface based on defect lattices and multiwave destructive interference","volume":"11","author":"Su","year":"2019","journal-title":"Phys. Rev. Appl."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"8182","DOI":"10.1038\/s41598-018-26386-5","article-title":"Uneven-Layered Coding Metamaterial Tile for Ultra-wideband RCS Reduction and Diffuse Scattering","volume":"8","author":"Su","year":"2018","journal-title":"Sci. Rep."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"16560","DOI":"10.1038\/s41598-017-16910-4","article-title":"Random Combinatorial Gradient Metasurface for Broadband, Wide-Angle and Polarization-Independent Diffusion Scattering","volume":"7","author":"Zhuang","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"20387","DOI":"10.1038\/srep20387","article-title":"An Ultra-wideband and Polarization-independent Metasurface for RCS Reduction","volume":"6","author":"Su","year":"2016","journal-title":"Sci. Rep."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"221110","DOI":"10.1063\/1.4881935","article-title":"Wideband radar cross section reduction using two-dimensional phase gradient metasurfaces","volume":"104","author":"Li","year":"2014","journal-title":"Appl. Phys. Lett."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1028","DOI":"10.1109\/LAWP.2015.2490241","article-title":"Wideband and Polarization-Independent Radar Cross Section Reduction Using Holographic Metasurface","volume":"15","author":"Liu","year":"2015","journal-title":"IEEE Antennas Wirel. Propag. Lett."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"435003","DOI":"10.1088\/1361-6463\/ab31f0","article-title":"Low cost, simple and broad band radar cross section reduction by modulated and holography metasurfaces","volume":"52","author":"Azizi","year":"2019","journal-title":"J. Phys. D Appl. Phys."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"333","DOI":"10.1126\/science.1210713","article-title":"Light Propagation with Phase Discontinuities: Generalized Laws of Reflection and Refraction","volume":"334","author":"Yu","year":"2011","journal-title":"Science"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"5144","DOI":"10.1109\/TAP.2015.2475628","article-title":"X-Band Phase-Gradient Metasurface for High-Gain Lens Antenna Application","volume":"63","author":"Li","year":"2015","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"4288","DOI":"10.1109\/TAP.2017.2710231","article-title":"A Circularly Polarized High-Gain Antenna With Low RCS Over a Wideband Using Chessboard Polarization Conversion Metasurfaces","volume":"65","author":"Li","year":"2017","journal-title":"IEEE Trans. Antennas Propag."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"145105","DOI":"10.1088\/1361-6463\/aab0d2","article-title":"Backscattered EM-wave manipulation using low cost 1-bit reflective surface at W-band","volume":"51","author":"Hong","year":"2018","journal-title":"J. Phys. D Appl. Phys."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"srep43543","DOI":"10.1038\/srep43543","article-title":"Wideband, wide-angle coding phase gradient metasurfaces based on Pancharatnam-Berry phase","volume":"7","author":"Zheng","year":"2017","journal-title":"Sci. Rep."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2193","DOI":"10.1109\/LAWP.2018.2870863","article-title":"Wideband RCS Reduction of a Slot Array Antenna Using Phase Gradient Metasurface","volume":"17","author":"Zhang","year":"2018","journal-title":"IEEE Antennas Wirel. Propag. Lett."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"205301","DOI":"10.1063\/5.0009651","article-title":"Ultra-wideband radar cross section reduction using amplitude and phase gradient modulated surface","volume":"128","author":"Azizi","year":"2020","journal-title":"J. Appl. Phys."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"402","DOI":"10.13164\/re.2018.0402","article-title":"Ultra-Wideband Robust RCS Reduction with Triangle-type AMC Structure","volume":"27","author":"Song","year":"2018","journal-title":"Radioengineering"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"122378","DOI":"10.1109\/ACCESS.2019.2937849","article-title":"4-Bit Optimized Coding Metasurface for Wideband RCS Reduction","volume":"7","author":"Saifullah","year":"2019","journal-title":"IEEE Access"},{"key":"ref_27","first-page":"184","article-title":"Bi-Static Radar Cross-Section Test Method by using Historic Marconi Set-up and Time Gating","volume":"37","author":"Azizi","year":"2022","journal-title":"Appl. Comput. Electromagn. Soc."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1109\/19.137345","article-title":"Automated swept-angle bistatic scattering measurements using continuous wave radar","volume":"41","author":"Cote","year":"1992","journal-title":"IEEE Trans. Instrum. Meas."},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Yang, F., and Rahmat-Samii, Y. (2009). Electromagnetic Band Gap Structures in Antenna Engineering, UK Cambridge University Press.","DOI":"10.1017\/CBO9780511754531"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"201601","DOI":"10.1063\/1.5026205","article-title":"Low cost and thin metasurface for ultra wide band and wide angle polarization insensitive radar cross section reduction","volume":"112","author":"Ameri","year":"2018","journal-title":"Appl. Phys. Lett."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/19\/7108\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:35:40Z","timestamp":1760142940000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/19\/7108"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,9,20]]},"references-count":30,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2022,10]]}},"alternative-id":["s22197108"],"URL":"https:\/\/doi.org\/10.3390\/s22197108","relation":{},"ISSN":["1424-8220"],"issn-type":[{"type":"electronic","value":"1424-8220"}],"subject":[],"published":{"date-parts":[[2022,9,20]]}}}