PURPOSE: To improve an MTI (moving target indicating function) characteristic by performing a frequency modulation to a pulse transmitting wave of a radar, extracting a demodulating wave of a modulating signal from a reflected receiving wave by said transmitting wave, and inputting it to the MTI.

CONSTITUTION: An FM modulator 23 is provided between a coherent oscillator 10 and a mixer 7, so that a frequency of a transmitting coherent signal is FM- modulated by a frequency of a modulated wave oscillator 22. An output of the FM-modulated oscillator 10 passes through the mixer 7 and reaches a klystron 3, in which said output becomes a transmitting high frequency pulse, and it is transmitted from an antenna 1. This receiving wave passes through a transmitting and receiving switch 2 from the antenna 1, it is converted to an intermediate frequency at a mixer 5, amplified by an intermediate amplifier 8 and inputted to a pulse form demodulator 40. A demodulated wave fetched by receiving a Doppler deviation in said demodulator is inputted to an MTI50 through a phase detector 9. As for the phase detector 9, an output signal of the modulated wave oscillator 22 is used as a reference signal.