Patent ID: 7498970

Claim:
A monitoring apparatus for being installed on a vehicle, sending out a radio wave, then receiving a radio wave generated by reflection of the radio wave, and thereby detecting a target including a material body and/or a human body, said apparatus comprising: a transmission antenna section for sending out from a common location a radio wave beam in different angular directions within an angular range of interest, wherein the beam has an angular range which is narrower than the angular range of interest; a receiving antenna section for receiving in each different beam direction the radio wave transmitted by said transmission antenna section and then reflected by said target; a transmission section of transmitting for said transmission antenna section a signal to be sent out as said radio wave; a receiving section to which the radio wave received by said receiving antenna section is transmitted as a signal from said receiving antenna section; beam switching instrument which switches the beam direction sequentially through the angular range of interest when said receiving antenna section receives said radio wave in said each different beam direction, in order to detect the target within the angular range of interest, and the beams are sequentially switched in directions that ensure that the angular range of each beam does not overlap substantially; and a running information storing section for storing running state information of said vehicle, wherein said receiving antenna section includes a first power feed section and a second power feed section, and wherein on the basis of said running state information stored in said running information storing section, said beam switching instrument performs switching such that power is fed to either said first power feed section or said second power feed section.