A pulse transmission controller generates transmission timing signals for a high-frequency radar transmission signal in every transmission cycle. A transmission phase shifter gives a transmission signal generated by a modulator phase shifts each corresponding to a transmission cycle on the basis of the transmission timing signals generated at intervals that are equal to the transmission cycle. A reception phase shifter gives a reception signal that is output from an A/D converter reception phase shifts that are opposite in direction to the respective transmission phase shifts given by the transmission phase shifter on the basis of the transmission timing signals generated at intervals that are equal to the transmission cycle.