Radar device and radar image generation method

A radar device, comprising:

• a transmitter to transmit transmission signals to space by using a plurality of transmission antennas arranged linearly and a receptor to receive reflected signals that are the transmission signals reflected in the space by using a plurality of reception antennas linearly arranged in the same direction as a plurality of the transmission antennas, and acquire digital data of the received signals;
• a controller to cause the transmitter and the receptor to repeatedly execute a series of processing in which the transmitter simultaneously transmits the transmission signals from a plurality of the transmission antennas and the receptor receives the reflected signals by a plurality of the reception antennas and acquires the digital data;
• and
• a signal processor to generate a three-dimensional radar image of a detection object moved in a direction crossing an antenna arrangement direction of a plurality of the transmission antennas and a plurality of the reception antennas by using the digital data sequentially acquired in the series of processing repeatedly executed as two-dimensional array data, wherein
• at least one first transmission antenna of a plurality of the transmission antennas is disposed at a first end of a substrate and at least one second transmission antenna of the plurality of transmission antennas is disposed at a second end of the substrate opposite to the first end of the substrate,
• the controller sets a pulse repetition interval of the transmission signals simultaneously transmitted from a plurality of the transmission antennas to be constant, and sets an initial phase change amount between the transmission signals at the pulse repetition interval to a different value for each of the transmission antennas,
• the transmitter simultaneously transmits the transmission signals having initial phase change amounts different for each of the transmission antennas from a plurality of the transmission antennas and multiplexes the transmission signals on a Doppler frequency axis such that the radar device implements a Doppler division multiplexing-multiple input multiple output (DDM-MIMO) system, and
• the signal processor generates two dimensional frequency signals by performing one dimensional Fourier transform on a plurality of reception signals which are reflected signals sequentially received in the pulse repetition intervals by the reception antenna, generates first compressed data by performing bulk compression on data of each reception path for each respective transmission antenna, generates three dimensional frequency signals by performing three dimensional Fourier transform on the plurality of reception signals parallel to generating the two dimensional frequency signals, generates signals of the three-dimensional radar image of the detection object for each of the transmission antennas using the two dimensional frequency signals and the three dimensional frequency signals generated in parallel and generates a final three-dimensional radar image of the detection object by coherently adding signals of the three-dimensional radar image generated for each of the transmission antennas.