Highly-integrated 28 GHz and 39 GHz array antennas for 5G mobile phone applications have been presented. The 28 GHz array consists of dual open-slots antennas as array elements and the 39 GHz array consists of folded loop antennas as array elements. This article demonstrates that 0.25 wavelength slot mode of the open-slots antenna and 1.5 wavelength loop mode of the folded loop antenna are promising candidates for generating directional radiation patterns fulfilling beam-scanning applications. And by properly designing the 0.25 wavelength slot mode to cover 28 GHz band and the 1.5 wavelength loop mode to cover the 39 GHz band, the proposed 28 GHz and 39 GHz array antennas can be compatible and coexisted at a limited side space of a mobile phone with keeping independent beam scanning operations for achieving a higher space utilization rate. This will be useful and attractive for future multiband and multimode millimeter wave mobile phone applications.