Patent ID: 7504990

Claim:
A radar apparatus comprising: a transmitter section having an antenna for radiating a transmit signal; a receiver section having a plurality of antennas for receiving said transmit signal reflected from an object, a first selector switch section for sequentially selecting output terminals of said plurality of antennas one at a time for connection to an input terminal, a first downconverting section for downconverting, by using a portion of said transmit signal, a received signal input from each of said antennas to said input terminal via said first selector switch section, a low-frequency cut-off filter connected to an output of said first downconverting section, and a second selector switch section for connecting an output of said low-frequency cut-off filter to a sequentially selected one of a plurality of A/D converters; and a digital signal processing section for receiving outputs of said plurality of A/D converters, and for applying prescribed processing to said outputs to detect distance to said object or relative velocity with respect to said object, wherein said first and second selector switch sections both operate with the same switching period (first period), and an on-off control section is provided which performs on-off control with a second period shorter than said first period when the output terminal of each of said plurality of antennas is connected to said input terminal.