PURPOSE: To eliminate interference waves only, by using two feedback loops(correlation loops), which is adapted to a signal inputted to a main and an auxiliary input terminal, proceeds the learning so as to minimize a signal power at an output terminal and forms the optimum weight of antenna.

CONSTITUTION: An output of a main antenna 11 is connected to an auxiliary input terminal 15 of the 1st correlation loop 13 and an output of an auxiliary antenna 12 is connected to a main input terminal 14 of the loop 13. The output of the antenna 11 is connected to a main input terminal 18 of the 2nd correlation loop 17, an output terminal 16 of the 1st correlation loop and an auxiliary input terminal 19 of the loop 17, and the final output is obtained from the output terminal 20 of the loop 17. In the 1st correlation loop, a desired signal component received at the auxiliary antenna is eliminated to contain the interference wave component only, and in the 2nd correlation loop, the interference wave received at the main antenna is eliminated with the interference wave component remained in the output of the 1st corrlation loop.