To solve a problem that at least one arrival angle detection antenna is required to be installed, a plurality of antennas including a communication antenna must be installed with high precision for the purpose of communication and positional detection, and arrival angle detection characteristics deteriorate because a radio wave received by the arrival angle detection antenna reflects in the housing.

A radio wave arrival angle detection antenna and a communication antenna are contained in the same housing such that the angle of at least one antenna can be adjusted. A shielding structure is arranged on the back and side of the arrival angle detection antenna and covered with a radio wave absorber on the side facing the arrival angle detection antenna. Consequently, arrival angle detection accuracy can be enhanced and installation cost can be lowered.