PURPOSE: To reduce the cost of a filter without using any analog delay line by providing the discrete time system of an uncyclic filter with a delay means which has a transfer function nearly equivalent to that of a CR primary circuit and arranging a switched capacitor at the delay means.

CONSTITUTION: An input xt and a Dirac delta function δt are applied to arithmetic circuits 20∼22 wich constitute the arithmetic part of the uncyclic filter and speicific arithmetic is carried out to apply output signals q1∼qn to multipliers 23∼25 as output devices. The outputs of those multipliers 23∼25 are summed up by an adder 26, which outputs a filter output signal yt. The arithmetic circuits 20∼23 of this filter are realized by the CR primary circuit of a capacitor Ck and a resistance Rk. Then, a circuit is composed of a switch 40, capacitors 41 and 42, and an operational amplifier 43, and the cost of the filter is reduced without using any analog delay line.