{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,24]],"date-time":"2026-04-24T20:46:38Z","timestamp":1777063598098,"version":"3.51.4"},"reference-count":40,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2023,2,23]],"date-time":"2023-02-23T00:00:00Z","timestamp":1677110400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Natural Science Foundation of China","award":["61501153"],"award-info":[{"award-number":["61501153"]}]},{"name":"National Natural Science Foundation of China","award":["GK219909299001-024"],"award-info":[{"award-number":["GK219909299001-024"]}]},{"name":"National Natural Science Foundation of China","award":["LQ22F010014"],"award-info":[{"award-number":["LQ22F010014"]}]},{"name":"Fundamental Research Funds for the Provincial Universities of Zhejiang","award":["61501153"],"award-info":[{"award-number":["61501153"]}]},{"name":"Fundamental Research Funds for the Provincial Universities of Zhejiang","award":["GK219909299001-024"],"award-info":[{"award-number":["GK219909299001-024"]}]},{"name":"Fundamental Research Funds for the Provincial Universities of Zhejiang","award":["LQ22F010014"],"award-info":[{"award-number":["LQ22F010014"]}]},{"name":"Zhejiang Provincial Natural Science Foundation of China","award":["61501153"],"award-info":[{"award-number":["61501153"]}]},{"name":"Zhejiang Provincial Natural Science Foundation of China","award":["GK219909299001-024"],"award-info":[{"award-number":["GK219909299001-024"]}]},{"name":"Zhejiang Provincial Natural Science Foundation of China","award":["LQ22F010014"],"award-info":[{"award-number":["LQ22F010014"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The demand for high-speed wireless communication systems has led to the development of ultrawide-band (UWB) antennas with a compact size and high performance. In this paper, we propose a novel four-port multiple-input multiple-output (MIMO) antenna with an asymptote-shaped structure that overcomes the limitations of existing designs for UWB applications. The antenna elements are placed orthogonally to each other for polarization diversity, and each element features a stepped rectangular patch with a tapered microstrip feedline. The unique structure of the antenna significantly reduces its dimensions to 42 \u00d7 42 mm2 (0.43\u03bb\u00d70.43\u03bb@\u00a03.09GHz), making it highly desirable for use in small wireless devices. To further enhance the antenna\u2019s performance, we use two parasitic tapes on the ground plane at the back as decoupling structures between adjacent elements. The tapes are designed in a windmill shape and a rotating extended cross shape, respectively, to further improve the isolation. We fabricated and measured the proposed antenna design on a single-layer substrate (FR4) with a dielectric constant of 4.4 and a thickness of 1 mm. The measured results show that the impedance bandwidth of the antenna is 3.09\u201312 GHz, with an isolation of \u221216.4 dB, an envelope correlation coefficient (ECC) of 0.02, a diversity gain (DG) of 9.991 dB, an average total effective reflection coefficient (TARC) of \u221220 dB, an overall group delay value less than 1.4 ns, and a peak gain of 5.1 dBi. Although there may be some antennas that have better performance in one or two specific aspects, our proposed antenna has an excellent trade-off among all the antenna characteristics including bandwidth, size, and isolation. The proposed antenna also exhibits good quasi-omnidirectional radiation properties, making it well-suited for a range of emerging UWB-MIMO communication systems, particularly in small wireless devices. In summary, the compact size and ultrawide-band capabilities of the proposed MIMO antenna design, coupled with its improved performance compared to other recent UWB-MIMO designs, make it a promising candidate for 5G and next-generation wireless communication systems.<\/jats:p>","DOI":"10.3390\/s23052484","type":"journal-article","created":{"date-parts":[[2023,2,24]],"date-time":"2023-02-24T02:03:26Z","timestamp":1677204206000},"page":"2484","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":27,"title":["A Compact High-Isolation Four-Element MIMO Antenna with Asymptote-Shaped Structure"],"prefix":"10.3390","volume":"23","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-9123-128X","authenticated-orcid":false,"given":"Aiting","family":"Wu","sequence":"first","affiliation":[{"name":"School of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yingxiang","family":"Tao","sequence":"additional","affiliation":[{"name":"School of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pengquan","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhonghai","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Zhihua","family":"Fang","sequence":"additional","affiliation":[{"name":"School of Electronics and Information, Hangzhou Dianzi University, Hangzhou 310018, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2023,2,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Powell, J., and Chandrakasan, A. 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