PURPOSE: To obtain stable antenna driving load even to an input signal of a corresponding band by performing the shift averaging by means of a delay for a correlative matrix to the input signal given from an antenna element and therefore obtaining said matrix through the low-pass filtering.

CONSTITUTION: Delay elements 27 and 28 are added to input signals x10 and x20 to obtain new signals x11 and x12, and the output signal (y) is produced from signals x10 and x20. In the same way. the signal y1 is obtained from signals x11 and x21 by means of mixers 29 and 30, an adder 31 and a band-pass filter 32. This signal y1 is mixed with signals x11 and x21 through mixers 33 and 34 and pass through adders 35 and 36 to produce the input signal to load generators 19 and 20. In such a way, the time average is obtained in place of the instantaneous value for a signal x*xT, and the estimation is possible with high accuracy for a correlative matrix R=E(x*xT) of the signal (x). Thus the load (w) is obtained forthe input signals of a wide range of bands. As a result, the adaptive load is possible for the input signals of a wide range of bands, and therefore the disturbance waves can be deleted effectively.