<?Pub Dtl?>A 60-GHz band planar dipole array antenna structure in a small wireless terminal is proposed for wide coverage area beamforming applications. Several substrates are stacked vertically by using 3-D system-in-package (SiP) technology, and the element antenna is installed on the substrates. A planar dipole antenna is used as an element antenna because it has a wider bandwidth than conventional patch antennas, which are widely used in 60-GHz band beamforming applications. Conventional dipole array antennas have a 1-D structure, or a 2-D structure arranged in multilayered substrate, resulting in narrow beamforming coverage area. The proposed structure has a wide beamforming coverage area because of the wide antenna spacing around . Design using numerical and 3-D electromagnetic field simulation indicate that a 4 2 arrangement is a feasible structure for a small wireless terminal with wide coverage area. Measurement results show that the designed array antenna has a wide coverage area, covering 75 and 95 in the theta and phi directions, respectively, with gain exceeding 10 dBi. The proposed planar dipole array structure using 3-D SiP technology is feasible as a 60-GHz band 2-D beamforming antenna in small wireless terminals.