{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T09:40:55Z","timestamp":1760175655460,"version":"build-2065373602"},"reference-count":18,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2020,3,11]],"date-time":"2020-03-11T00:00:00Z","timestamp":1583884800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"MINISTERIO DE EDUCACI\u00d3N Y CIENCIA (SPAIN)","award":["TEC2016-78028-C3-1-P and TEC2016-78028-C3-2-P"],"award-info":[{"award-number":["TEC2016-78028-C3-1-P and TEC2016-78028-C3-2-P"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Millimeter-wave and terahertz frequencies offer unique characteristics to simultaneously obtain good spatial resolution and penetrability. In this paper, a robust near-field monostatic focusing technique is presented and successfully applied for the internal imaging of different penetrable geometries. These geometries and environments are related to the growing need to furnish new vehicles with radar-sensing devices that can visualize their surroundings in a clear and robust way. Sub-millimeter-wave radar sensing offers enhanced capabilities in providing information with a high level of accuracy and quality, even under adverse weather conditions. The aim of this paper was to research the capability of this radar system for imaging purposes from an analytical and experimental point of view. Two sets of measurements, using reference targets, were performed in the W band at 100 GHz (75 to 110 GHz) and terahertz band at 300 GHz (220 to 330 GHz). The results show spatial resolutions of millimeters in both the range (longitudinal) and the cross-range (transversal) dimensions for the two different imaging geometries in terms of the location of the transmitter and receiver (frontal or lateral views). The imaging quality in terms of spatial accuracy and target material parameter was investigated and optimized.<\/jats:p>","DOI":"10.3390\/s20061544","type":"journal-article","created":{"date-parts":[[2020,3,12]],"date-time":"2020-03-12T04:13:57Z","timestamp":1583986437000},"page":"1544","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Linear and Circular UWB Millimeter-Wave and Terahertz Monostatic Near-Field Synthetic Aperture Imaging"],"prefix":"10.3390","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8688-2136","authenticated-orcid":false,"given":"Jose Antonio","family":"Solano-Perez","sequence":"first","affiliation":[{"name":"Departamento Tecnolog\u00edas de la Informaci\u00f3n y las Comunicaciones, Universidad Polit\u00e9cnica de Cartagena, Cartagena, 30202 Murcia, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8047-7655","authenticated-orcid":false,"given":"Mar\u00eda-Teresa","family":"Mart\u00ednez-Ingl\u00e9s","sequence":"additional","affiliation":[{"name":"Centro Universitario de la Defensa, Universidad Polit\u00e9cnica de Cartagena, Base A\u00e9rea de San Javier. Academia General del Aire, 30720 Murcia, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6415-7363","authenticated-orcid":false,"given":"Jose-Maria","family":"Molina-Garcia-Pardo","sequence":"additional","affiliation":[{"name":"Departamento Tecnolog\u00edas de la Informaci\u00f3n y las Comunicaciones, Universidad Polit\u00e9cnica de Cartagena, Cartagena, 30202 Murcia, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0197-5961","authenticated-orcid":false,"given":"Jordi","family":"Romeu","sequence":"additional","affiliation":[{"name":"CommSenslab, Department of Signal Theory and Communications, School of Telecommunications Engineering Technical University of Catalonia (Universitat Politecnica de Catalunya, UPC) Campus Nord UPC, Edif. 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