{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,28]],"date-time":"2026-01-28T06:42:52Z","timestamp":1769582572494,"version":"3.49.0"},"reference-count":19,"publisher":"MDPI AG","issue":"20","license":[{"start":{"date-parts":[[2019,10,14]],"date-time":"2019-10-14T00:00:00Z","timestamp":1571011200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Samsung Research Funding Center of Samsung Electronics","award":["SRFC-IT1401-00"],"award-info":[{"award-number":["SRFC-IT1401-00"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>A parametric array (PA) loudspeaker is a highly directional audio source that might grant one's convenience if it is used with mobile devices. However, conventional PA loudspeakers is almost impossible to apply in mobile devices using a battery because of the large power consumption and large device size. In this study, a PA loudspeaker system (PALS) was fabricated and evaluated to show that those difficulties could be overcome to apply it to mobile devices. In order to construct a PALS for demonstration, a power amplifier and signal-processing unit should also be properly designed and built. The PA source transducer should also be designed and built for a mobile device application. These components were integrated into a single PALS. The PALS generated a 125-dB primary wave and 62 dB of a different frequency wave (DFW) through the PA at 0.45 m in a 3 m \u00d7 3 m \u00d7 2 m semi-anechoic chamber. We confirmed that the half-power bandwidth (HPBW) formed a 6\u00b0 beam at 83 kHz of DFW and 90 kHz of the primary wave (PW), and the HPBW formed a 7.3\u00b0 beam at 5 kHz of DFW and a 7.1\u00b0 beam at 10 kHz of DFW, respectively. Lastly, the power required was 6.65 W without a matching circuit, and 3.25 W with such a circuit.<\/jats:p>","DOI":"10.3390\/s19204449","type":"journal-article","created":{"date-parts":[[2019,10,14]],"date-time":"2019-10-14T12:14:05Z","timestamp":1571055245000},"page":"4449","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["A Critical Step to Using a Parametric Array Loudspeaker in Mobile Devices"],"prefix":"10.3390","volume":"19","author":[{"given":"Hongmin","family":"Ahn","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, POSTECH, Pohang 37673, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kyounghun","family":"Been","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, POSTECH, Pohang 37673, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2069-2748","authenticated-orcid":false,"given":"In-Dong","family":"Kim","sequence":"additional","affiliation":[{"name":"Department of Electrical Engineering, Pukyoung National University, Busan 48513, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chong Hyun","family":"Lee","sequence":"additional","affiliation":[{"name":"Department of Ocean System Engineering, Jeju National University,  Jeju 63243, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wonkyu","family":"Moon","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, POSTECH, Pohang 37673, Korea"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,10,14]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1532","DOI":"10.1121\/1.389414","article-title":"The audio spotlight: An application of nonlinear interaction of sound waves to a new type of loudspeaker design","volume":"73","author":"Yoneyama","year":"1983","journal-title":"J. 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Microeng."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/20\/4449\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:26:08Z","timestamp":1760189168000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/19\/20\/4449"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,10,14]]},"references-count":19,"journal-issue":{"issue":"20","published-online":{"date-parts":[[2019,10]]}},"alternative-id":["s19204449"],"URL":"https:\/\/doi.org\/10.3390\/s19204449","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,10,14]]}}}