Monopulse radar apparatus and antenna switch

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
• at least three array antennas composed of the antenna elements, and
• a monopulse process is performed based on outputs of at least three sets of a pair of array antennas, wherein the at least three 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 the at least three sets of a pair of array antennas have different distances between antenna element groups thereof.

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
• at least three array antennas,
• the azimuth angle of the target is calculated for each phase difference detected based on outputs of at least two sets of a pair of array antennas, and
• targets of a same speed and a same distance are selected from calculated azimuth angles, wherein
• the at least three 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 the at least two sets of pair of array antennas have different distances between antenna element groups thereof.

An antenna switch that selectively connects a plurality of antennas to either a transmitter or a receiver, the antenna switch comprising:

• a first amplifier that amplifies a transmission signal from the transmitter, and supplies amplified transmission signal to one antenna;
• a second amplifier that amplifies a reception signal of the one antenna;
• a plurality of third amplifiers that amplify reception signals of other antennas, respectively;
• and
• a first switch that selects one of an output of said second amplifier and outputs of said third amplifiers, and supplies selected output to the receiver;
• a second switch that is provided between the output of said first amplifier and the one antenna;
• and
• a third switch that is provided between the one antenna and said second amplifier, wherein
• turning on/off of said first amplifier is interlocked with turning on/off of said second switch,
• turning on/off of said second amplifier is interlocked with turning on/off of said third switch, and
• turning on/off either said second amplifier or one of said third amplifiers is interlocked with a selection of said first switch.