{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,14]],"date-time":"2025-10-14T07:14:57Z","timestamp":1760426097429,"version":"build-2065373602"},"reference-count":38,"publisher":"MDPI AG","issue":"21","license":[{"start":{"date-parts":[[2022,11,1]],"date-time":"2022-11-01T00:00:00Z","timestamp":1667260800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Constanta Maritime University"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Protected wetlands such as deltas, lakes or rivers provide a sanctuary for many endangered species. In order to protect these areas from illegal human interventions, it is necessary to monitor the unauthorized entrance of motor boats. In order to mitigate such an impact, we have developed a network of floating beacons for underwater acoustic monitoring, using LoRa communication modules operating at 433 MHz. Such beacons should be equipped with compact antennas. In this paper, we use a genetic algorithm approach to design the compact, monopole antennas required for the beacons; size constraints would apply not only to the radiating element but also to the ground plane. Although the antenna input is unbalanced, such a small ground plane may yield common mode currents on the antenna feeder, which distort the radiation pattern of the antenna. In order to investigate the effect of the common mode currents, we developed a distance averaging method, while, for characterizing the antenna, we used a single-antenna method. For the experimental validation of the system in real conditions, a continuous monitoring of the lake was carried out. During the monitoring, multiple events generated by incursions of motor boats were successfully detected and recorded.<\/jats:p>","DOI":"10.3390\/s22218392","type":"journal-article","created":{"date-parts":[[2022,11,2]],"date-time":"2022-11-02T08:15:12Z","timestamp":1667376912000},"page":"8392","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["A Compact Monopole Antenna for Underwater Acoustic Monitoring Beacons"],"prefix":"10.3390","volume":"22","author":[{"given":"Stefania","family":"Bucuci","sequence":"first","affiliation":[{"name":"Department of Electronics and Telecommunications, Constanta Maritime University, 900663 Constanta, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8681-8596","authenticated-orcid":false,"given":"Andreea","family":"Constantin","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, Constanta Maritime University, 900663 Constanta, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Mirel","family":"Paun","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, Constanta Maritime University, 900663 Constanta, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marius N.","family":"Pastorcici","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, Constanta Maritime University, 900663 Constanta, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9253-6256","authenticated-orcid":false,"given":"Razvan D.","family":"Tamas","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, Constanta Maritime University, 900663 Constanta, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Alin","family":"Danisor","sequence":"additional","affiliation":[{"name":"Department of Electronics and Telecommunications, Constanta Maritime University, 900663 Constanta, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7744-2518","authenticated-orcid":false,"given":"Rodica","family":"Constantinescu","sequence":"additional","affiliation":[{"name":"Department of Applied Electronics, University Politehnica of Bucharest, 061071 Bucharest, Romania"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2022,11,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"12304","DOI":"10.3390\/ijerph121012304","article-title":"Noise in the Sea and Its Impacts on Marine Organisms","volume":"12","author":"Peng","year":"2015","journal-title":"Int. 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