PURPOSE: To prevent a disturbing wave component from appearing at an output, by setting the zero-point direction of the directivity of the auxiliary antenna of a side lobe canceler to that of a main antenna.

CONSTITUTION: The reception output of a main antenna 1 is led to a main channel 4 through a difference circuit 3, and that of an auxiliary antenna 2 to an auxiliary channel 5 respectively. An adaptive loop 6 collates the singal of the main channel 4 with that of the auxiliary channel 5 and eliminates a disturbing wave component having strong correlation by using the correlation output, and this is composed of correlator 7, an amplifier 8, an integrator 9, a multiplier 10, and the diffevence circuit 3. Then, the adaptive loop 6 does not operate with a disturbing wave in the zero-point direction of the directivity of the antenna, but the zero-point direction of directivity of the antenna 2 is coincident with that of the antenna 1, so that the disturbing wave component never appears at the main channel 4.