{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:38:18Z","timestamp":1760143098189,"version":"build-2065373602"},"reference-count":37,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2024,1,22]],"date-time":"2024-01-22T00:00:00Z","timestamp":1705881600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001691","name":"JSPS KAKENHI","doi-asserted-by":"publisher","award":["20F20762"],"award-info":[{"award-number":["20F20762"]}],"id":[{"id":"10.13039\/501100001691","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>This article presents a 4-way 2-D butler matrix (BM)-based beamforming network (BFN) using a multilayer substrate broadside coupled stripline (BCS). To achieve the characteristics of a compact, wide-bandwidth, high-gain phased array, a BCS coupler is implemented using the Megtron 6 substrate. The compact 2-D BFN is formed by combining planarly two horizontal BCS couplers and two vertical BCS couplers. The BFN is proposed without a crossover and without a phase shifter, generating phase responses of \u00b190\u00b0 in the x- and y-directions, respectively. The proposed BFN exhibits a wide operating band of 66.7% (3\u20137 GHz) and a compact physical area of just 0.25 \u03bb0 \u00d7 0.25 \u03bb0 \u00d7 0.04 \u03bb0. The planar 2-D BFN is easily integrated with the patch antenna radiation elements to construct a 2-D multibeam array antenna that generates four fixed beams, one in each quadrant, at an elevation angle of 30\u00b0 from the broadside to the array axis when the element separation is 0.6 \u03bb0. The physical area of the 2-D multibeam array antenna is just 0.8 \u03bb0 \u00d7 0.8 \u03bb0 \u00d7 0.04 \u03bb0. The prototypes of the BCS coupler, the 2-D BFN, and the 2-D multibeam array antenna were fabricated and measured. The measured and simulated results were in good agreement. A gain of 9.1 to 9.9 dBi was measured.<\/jats:p>","DOI":"10.3390\/s24020714","type":"journal-article","created":{"date-parts":[[2024,1,22]],"date-time":"2024-01-22T12:01:13Z","timestamp":1705924873000},"page":"714","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["A Compact Broadside Coupled Stripline 2-D Beamforming Network and Its Application to a 2-D Beam Scanning Array Antenna Using Panasonic Megtron 6 Substrate"],"prefix":"10.3390","volume":"24","author":[{"given":"Jean","family":"Temga","sequence":"first","affiliation":[{"name":"Millimeter Wave Technologies, Intelligent Wireless System, Silicon Austria Labs (SAL), 4040 Linz, Austria"},{"name":"Research Institute of Electrical Communication, Tohoku University, Miyagi 980-0812, Japan"}]},{"given":"Takashi","family":"Shiba","sequence":"additional","affiliation":[{"name":"Research Institute of Electrical Communication, Tohoku University, Miyagi 980-0812, Japan"}]},{"given":"Noriharu","family":"Suematsu","sequence":"additional","affiliation":[{"name":"Research Institute of Electrical Communication, Tohoku University, Miyagi 980-0812, Japan"}]}],"member":"1968","published-online":{"date-parts":[[2024,1,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"6231","DOI":"10.1109\/TAP.2017.2712819","article-title":"Multibeam antenna technologies for 5G wireless communications","volume":"65","author":"Hong","year":"2017","journal-title":"IEEE Trans. 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