Disclosed is a radar apparatus which receives a transmitted signal
reflected from an object by switching between a plurality of antennas,
wherein the plurality of antennas are divided into a plurality of groups,
and at least one of the plurality of antennas contained in each of the
groups is a common antenna. The radar apparatus comprises: a selector
switch section having a plurality of selector switches each for
sequentially and selectively switching output terminals of the plurality
of antennas and the common antenna contained in a corresponding one of the
groups for connection to an input terminal; a plurality of channels each
having an A/D converter and a downconverting section for downconverting a
received signal that has been input from each of the antennas to the input
terminal via a corresponding one of the plurality of selector switches;
and a digital signal processing section for receiving an output from the
A/D converter of each of the channels, wherein the digital signal
processing section applies prescribed processing to detect the distance to
or the relative velocity of the object.