Patent ID: 8547273

Claim:
A pulse radar apparatus, comprising: a high-frequency transmitting section having an oscillator that generates a carrier wave of a predetermined frequency and configured to generate a pulsed transmission signal by cutting out the carrier wave generated by the oscillator in accordance to two or more transmission control signals; a transmitting antenna configured to input the transmission signal from the high-frequency transmitting section to radiate to the air as radio wave; a receiving antenna configured to receive reflected wave of the radio wave reflected by an object; a high-frequency receiving section configured to input a received signal from the receiving antenna to down-convert to a baseband signal by correlating with the transmission signal in accordance to at least one receiving control signal; and a baseband section including: an A/D converting unit configured to input the baseband signal to convert into a digital signal, a digital signal processing unit configured to input the digital signal from the A/D converting unit to calculate a distance to the object and/or relative speed of the object and/or an azimuth angle of the object, and a control unit configured to output the transmission control signals to the high-frequency transmitting section and to output at least one receiving control signal to the high-frequency receiving section; wherein when the transmission control signals are denoted as X 1 through Xm (m≧2) and when the digital signal output of the A/D converting unit is denoted as an i −th background signal when the control unit outputs no i −th transmission control signal Xi among the transmission control signals while outputting the transmitting and receiving control signals except of the i −th signal, the digital signal processing unit is configured to select sequentially the transmission control signals X 1 to Xm as the i −th transmission control signal Xi to acquire the digital signals output of the A/D converting unit respectively as the first through the m −th background signals when the control unit outputs the transmitting and receiving control signals except of the transmission control signal Xi, to acquire the digital signal output of the A/D converting unit as a (m+1) −th background signal when the control unit outputs the receiving control signal without outputting any of the m transmission control signals, and to calculate a replica signal by adding the first through the m −th background signals, by subtracting the (m+1) −th background signal, and by dividing by (m−1); to calculate a low-noise signal by subtracting the replica signal from the digital signal output of the A/D converting unit when the control unit outputs the m transmission control signals and the receiving control signal; and to calculate a distance to the object and/or a relative speed of the object and/or an azimuth angle of the object based on the low-noise signal.