A mobile wireless communications device may include a portable housing, and a printed circuit board (PCB) carried by the housing and having opposing upper and lower portions. The device may also include at least one wireless transceiver carried by the portable housing, and a satellite positioning signal receiver carried by the portable housing. An antenna assembly may be carried adjacent the upper portion of the PCB. The antenna assembly may include a horizontal conductor extending along the upper portion of the PCB in spaced relation therefrom. The horizontal conductor may be coupled to the satellite positioning receiver. The antenna assembly may also include a loop conductor extending from the horizontal conductor toward the lower portion of the PCB and in spaced relation from the PCB. The loop conductor may be coupled to the wireless transceiver.