Systems and methods are disclosed to provide power management for a mobile communication device having a location determination function. When ID detection timing is provided from a timing detector to a switch, relative amplitudephase data related to the tag ID digital value \u201c1\u201d or \u201c0\u201d is obtained by an arrival direction estimation unit. A spacer is projected from at least two positions of a part of the outer wall portion and the second step portion in a temporary locking position, and is sunken in the outer wall portion or arranged in the same plane as the outer wall portion in a regular locking position. A drift zone of the second conductivity type is arranged below the body region and a second highly-doped region of the second conductivity type is arranged below the drift zone.