A portable electronic device includes a housing, a display at least partially within the housing, a front cover coupled to the housing and positioned over the display, a rear cover coupled to the housing and defining a first portion of a rear exterior surface of the portable electronic device, a protrusion defining a sensor array region of the rear cover and a second portion of the rear exterior surface, and an internal surface opposite the second portion of the rear exterior surface. The portable electronic device also includes a sensor array mounted within the housing along the sensor array region and comprising a frame member coupled to the rear cover along the internal surface and defining a wall structure defining a first container region and a second container region, a camera module positioned in the first container region, and a depth sensor module positioned in the second container region and attached to the internal surface of the rear cover.