Radar apparatus

A radar apparatus comprising:

• an antenna section including a transmitting antenna and a receiving antenna, the transmitting antenna transmitting a radar wave responding to a high-frequency signal, the receiving antenna receiving a reflected wave, which is produced by reflection of the radar wave by a target, and outputting a reception signal responding to the reflected wave;
• a high-frequency circuit section that generates the high-frequency signal and produces a low-frequency signal based on the reception signal outputted from the receiving antenna and the high-frequency signal;
• a low-frequency circuit section that determines information about the target, which has reflected the radar wave, based on the low-frequency signal produced by the high-frequency circuit section;
• a plate-shaped main printed board having a major face, the major face having such an area that both the high-frequency circuit section and the low-frequency circuit section can be mounted on the major face;
• and
• a plate-shaped secondary printed board having first and second faces, the first face having such an area that the high-frequency circuit section can be mounted on the first face, the second face being on a back side of the first face,
• wherein
• the low-frequency circuit section is arranged on the major face of the main printed board,
• the high-frequency circuit section and the antenna section are arranged respectively on the first and second faces of the secondary printed board, and
• the secondary printed board is mounted to a space on the major face of the main printed board which is not occupied by the low-frequency circuit section.