PURPOSE: To form a digital linear phase filter in an analog form by connecting (P-1) units of delay devices having a basic cycle and multiplying the outputs of these delay devices by a K-fold coefficient.

CONSTITUTION: The (P-1) units of delay devices (11∼1)∼(11∼P-1) having a basic cycle are cascaded, and the outputs of these delay devices are multiplied by K by coefficient devices (12∼1)∼(12∼P) respectively. The outputs of these coefficient devices are added by an adder 13. Thus the transmission function of such a linear phase filter can be shown by an equation. As a result, a digital linear phase filter can be formed in an analog form.