Li, ShupingShupingLiChiu, Kun DongKun DongChiuGao, DonglinDonglinGaoCHUNG-TSE WUKuo, Chien NanChien NanKuo2024-03-012024-03-012023-12-0115361225https://scholars.lib.ntu.edu.tw/handle/123456789/640071In this letter, we propose a low-profile beamforming array operating in the W-band, which is based on the Butler matrix integrated with substrate-integrated waveguide metamaterial (MTM) antennas. The proposed MTM antenna achieves an enhanced bandwidth through the use of multiple resonance modes of the composite right/left-hand structure. The implementation of the proposed array is done using a low-cost glass-based integrated-passive-device (IPD) technology. The microstrip-type Butler matrix with crossover structures is designed, and its bandwidth of 12.8% at the W-band is verified with measurements. Experimental verifications of the radiation patterns are conducted to demonstrate the beamforming characteristics of the proposed IPD antenna array.Butler matrix | integrated passive device (IPD) technology | phased array | substrate integrated waveguide (SIW) | W-bandjournal article10.1109/LAWP.2023.33041382-s2.0-85167817251https://api.elsevier.com/content/abstract/scopus_id/85167817251