A communication device, computer program product, and method enable associating a closed position and an open position of a movable housing positionably coupled to a base housing of the communication device with alternate ones of first and second modes of antenna communication that respectively utilize an antenna array of a first sub-array aligned or not aligned in a second sub-array. The first array of first antenna(s) is housed within the base housing. The second sub-array of second antenna(s) is housed within the movable housing. The controller monitors a housing sensor positioned to detect the closed position and the open position. In response to identifying the mode, the controller configures a modem to use an excitation matrix associated with the mode comprising magnitude and phase settings to apply to each antenna of the first and the second sub-arrays to act either independently or as an array.