Radar apparatus and signal generating apparatus

A radar apparatus comprising:

• a pulse generator which, in operation, sequentially generates, in each transmission cycle, a digital transmission pulse signal including an in-phase (I) component and a quadrature (Q) component;
• a phase rotator which, in operation, sequentially applies, in each transmission cycle, a first phase rotation to the digital transmission pulse signal;
• a digital-to-analog converter (DAC) which, in operation, converts the digital transmission pulse signal, to which the first phase rotation is applied, to a transmission baseband analog signal;
• a transmitter which, in operation, converts the transmission baseband analog signal to a radar signal on a radio frequency and transmits the radar signal;
• a receiver which, in operation, receives a reflected wave signal resulting from the radar signal being reflected on an object and converts the reflected wave signal to a reception baseband analog signal;
• an analog-to-digital converter (ADC) which, in operation, converts the reception baseband analog signal to a digital reception pulse signals including an in-phase (I) component and a quadrature (Q) component;
• a correlator which, in operation, calculates a correlation value between the digital transmission pulse signals and the digital reception pulse signals;
• an error estimator which, in operation, estimates, on the basis of the correlation value, an I component error and a Q component error included in the digital reception pulse signals;
• a correction parameter calculator which, in operation, calculates a correction parameter for correcting the I component error and the Q component error;
• and
• an error corrector which, in operation, corrects, on the basis of the correction parameter, the I component error and the Q component error included in at least one of the digital transmission pulse signals and the digital reception pulse signals.