Patent ID: 7612706

Claim:
A monopulse radar apparatus comprising: a transmitter that generates a transmission signal to detect a target, and outputs generated transmission signal; an antenna unit including at least one transmission antenna; and a plurality of reception antennas; a receiver that detects information including azimuth information for the target, based on an output from the antenna unit; and an antenna switching unit that switches a connection between the transmitter and the transmission antenna and a connection between the reception antenna and the receiver, wherein said antenna unit includes a wide-beam array antenna and multiple narrow-beam array antennas having a narrower beam width than said wide-beam array antenna, wherein the wide-beam array antenna and the multiple narrow-beam array antennas are respectively constructed from multiple antenna element groups, the multiple antenna element groups being selected in a unit of row or column from an array of antenna elements having at least 6 rows or at least 6 columns so that a distance between the multiple antenna element groups for each of the multiple narrow-beam antennas is larger than a distance between the multiple antenna element groups for the wide-beam antenna, and a monopulse process is performed based on an output of the pair of said reception antenna, wherein any one of the wide-beam array antenna and the multiple narrow-beam array antennas functions as the transmission antenna or the reception antenna as needed.