Referring to FIG. 12, in an antenna module 500D according to another exemplary embodiment, a connection substrate 430 may be disposed instead of the connector on a side portion of an antenna substrate 100D and be connected to a side surface of the antenna substrate 100D. In this case, an electronic component 300 may be surface-mounted on an upper surface of the connection substrate 430 through a solder adhesive, or the like, and be electrically connected to the antenna substrate 100D through the connection substrate 430. That is, the electronic component 300 having a great thickness may be disposed on the side portion of the antenna substrate 100D through the connection substrate 430. Therefore, an overall thickness of the antenna module 500D may further be reduced. The connection substrate 430 may be any known RFPCB or FCPB integrated with the antenna substrate 100D. For example, one or two lower insulating layers 111b of the antenna substrate 100D may be insulating layers formed of a material having flexible characteristics, such as polyimide and provide a flexible PCB region out of a rigid PCB region of the antenna substrate 100D, a rigid PCB region may be formed at an end portion of the flexible PCB region, if necessary, and the flexible PCB region or a flexible-rigid PCB region may be used as the connection substrate 430. That is, the antenna substrate 100D itself may be a rigid-flexible PCB (RFPCB) or a rigid-flexible-rigid (RFRPCB). In this case, the rigid PCB region may be used as the antenna substrate 100D, and the flexible PCB region or the flexible-rigid PCB region may be used as the connection substrate 430. The antenna module 500D may be electrically connected to other components in a set, such as a mainboard, and the like, in a set through the connection substrate 430. Other configurations overlap those described above in the antenna module 500A according to the exemplary embodiment, and a detailed description thereof is thus omitted.