Embodiments of a millimeter-wave (mmW) communication device and methods for intelligent control of transmit power and power density are generally described herein. In some embodiments, a mmW base station includes a beamforming processor that is to configure a large-aperture array antenna for multi-beam transmissions at mmW frequencies to a plurality of user equipment (UE). The beamforming processor may allocate each UE a non-interfering spectral portion of a full channel bandwidth that is substantially less than the full channel bandwidth and perform multi-beam beamforming to concurrently direct a plurality of multi-user multiple-input multiple-output (MU-MIMO) antenna beams to the UEs for a concurrent transmission of data streams to the UEs within their allocated spectral portion in accordance with a transmit power allocation.