{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,19]],"date-time":"2026-02-19T03:37:30Z","timestamp":1771472250916,"version":"3.50.1"},"reference-count":49,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2021,4,6]],"date-time":"2021-04-06T00:00:00Z","timestamp":1617667200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100007273","name":"Comisi\u00f3n Interministerial de Ciencia y Tecnolog\u00eda","doi-asserted-by":"publisher","award":["TEC2013-47360-C3-1-P\/AEI\/10.13039\/501100011033"],"award-info":[{"award-number":["TEC2013-47360-C3-1-P\/AEI\/10.13039\/501100011033"]}],"id":[{"id":"10.13039\/501100007273","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007273","name":"Comisi\u00f3n Interministerial de Ciencia y Tecnolog\u00eda","doi-asserted-by":"publisher","award":["TEC2016-78028-C3-1-P\/AEI\/10.13039\/501100011033"],"award-info":[{"award-number":["TEC2016-78028-C3-1-P\/AEI\/10.13039\/501100011033"]}],"id":[{"id":"10.13039\/501100007273","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007273","name":"Comisi\u00f3n Interministerial de Ciencia y Tecnolog\u00eda","doi-asserted-by":"publisher","award":["MDM2016-O6OO"],"award-info":[{"award-number":["MDM2016-O6OO"]}],"id":[{"id":"10.13039\/501100007273","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100007273","name":"Comisi\u00f3n Interministerial de Ciencia y Tecnolog\u00eda","doi-asserted-by":"publisher","award":["Catalan Research Group 2017 SGR 219"],"award-info":[{"award-number":["Catalan Research Group 2017 SGR 219"]}],"id":[{"id":"10.13039\/501100007273","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/100007637","name":"Departamento Administrativo de Ciencia, Tecnolog\u00eda e Innovaci\u00f3n (COLCIENCIAS)","doi-asserted-by":"publisher","award":["Convocatoria 727 de 2015"],"award-info":[{"award-number":["Convocatoria 727 de 2015"]}],"id":[{"id":"10.13039\/100007637","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Nonlinear effects in the radio front-end can degrade communication quality and system performance. In this paper we present a new design technique for reconfigurable antennas that minimizes the nonlinear distortion and maximizes power efficiency through the minimization of the coupling between the internal switching ports and the external feeding ports. As a nonlinear design and validation instance, we present the nonlinear characterization up to 50 GHz of a PIN diode commonly used as a switch for reconfigurable devices in the microwave band. Nonlinear models are extracted through X-parameter measurements supported by accurate calibration and de-embedding procedures. Nonlinear switch models are validated by S-parameter measurements in the low power signal regime and by harmonic measurements in the large-signal regime and are further used to predict the measured nonlinearities of a reconfigurable antenna. These models have the desired particularity of being integrated straightforwardly in the internal multi-port method formulation, which is used and extended to account for the power induced on the switching elements. A new figure of merit for the design of reconfigurable antennas is introduced\u2014the power margin, that is, the power difference between the fed port and the switching elements, which combined with the nonlinear load models directly translates into nonlinearities and power-efficiency-related metrics. Therefore, beyond traditional antenna aspects such as port match, gain, and beam orientation, switch power criteria are included in the design methodology. Guidelines for the design of reconfigurable antennas and parasitic layers of minimum nonlinearity are provided as well as the inherent trade-offs. A particular antenna design suitable for 5G communications in the 3.5 GHz band is presented according to these guidelines, in which the specific switching states for a set of target performance metrics are obtained via a balancing of the available figures of merit with multi-objective separation criteria, which enables good control of the various design trade-offs. Average Error Vector Magnitude (EVM) and power efficiency improvement of 12 and 6 dB, respectively, are obtained with the application of this design approach. In summary, this paper introduces a new framework for the nonlinear modeling and design of reconfigurable antennas and provides a set of general-purpose tools applicable in cases beyond those used as examples and validation in this work. Additionally, the use of these models and guidelines is presented, demonstrating one of the most appealing advantages of the reconfigurable parasitic layer approach, their low nonlinearity.<\/jats:p>","DOI":"10.3390\/s21072557","type":"journal-article","created":{"date-parts":[[2021,4,6]],"date-time":"2021-04-06T10:34:12Z","timestamp":1617705252000},"page":"2557","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":8,"title":["Design of Minimum Nonlinear Distortion Reconfigurable Antennas for Next-Generation Communication Systems"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2913-2720","authenticated-orcid":false,"given":"Germ\u00e1n Augusto","family":"Ram\u00edrez Arroyave","sequence":"first","affiliation":[{"name":"Department of Signal Theory and Communications (TSC), School of Telecommunications Engineering, Universitat Polit\u00e8cnica de Catalunya (UPC), Campus Nord, 08034 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1176-1329","authenticated-orcid":false,"given":"Antoni","family":"Barlab\u00e9","sequence":"additional","affiliation":[{"name":"Department of Signal Theory and Communications (TSC), School of Telecommunications Engineering, Universitat Polit\u00e8cnica de Catalunya (UPC), Campus Nord, 08034 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4026-226X","authenticated-orcid":false,"given":"Llu\u00eds","family":"Pradell","sequence":"additional","affiliation":[{"name":"Department of Signal Theory and Communications (TSC), School of Telecommunications Engineering, Universitat Polit\u00e8cnica de Catalunya (UPC), Campus Nord, 08034 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4218-9887","authenticated-orcid":false,"given":"Javier Leonardo","family":"Araque Quijano","sequence":"additional","affiliation":[{"name":"Department of Electrical and Electronic Engineering (DIEE), Faculty of Engineering, Universidad Nacional de Colombia, Ciudad Universitaria, Bogot\u00e1 111321, Colombia"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5067-2038","authenticated-orcid":false,"given":"Bedri A.","family":"Cetiner","sequence":"additional","affiliation":[{"name":"Electrical and Computer Engineering Department, Utah State University, 4120 Old Main Hill, Logan, UT 84322-4120, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0547-901X","authenticated-orcid":false,"given":"Luis","family":"Jofre-Roca","sequence":"additional","affiliation":[{"name":"Department of Signal Theory and Communications (TSC), School of Telecommunications Engineering, Universitat Polit\u00e8cnica de Catalunya (UPC), Campus Nord, 08034 Barcelona, Spain"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2021,4,6]]},"reference":[{"key":"ref_1","unstructured":"3GPP TS 38.101-1 V16.6.0 (2021). 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