Embodiments of the disclosure relate to a remote antenna unit (RAU) with multiple antenna assembly in a distributed antenna system (DAS). In this regard, an RAU(s) in a DAS includes a plurality of directional antennas, a power generation circuit, and a controller. The power generation circuit is configured to generate a power output having an aggregated power. The controller is configured to allocate the aggregated power to the directional antennas based on a power allocation scheme. By allocating the aggregated power between the directional antennas based on the power allocation scheme, it is possible to programmably control radiation patterns and transmission powers of the directional antennas in the RAU(s). As a result, it is possible to provide optimized radio frequency (RF) coverage throughout a coverage area(s) of the RAU(s) without preconfiguring the radiation patterns and transmission powers of the directional antennas.