Abstract: A pulse compression filter designed as a dispersive delay line functions with acoustic waves having a mean wavelength .lambda..sub.o in the filter. At least one input/output transducer or at least one reflector arrangement is provided with a plurality of electrode respectively reflector fingers distributed on a substrate in accordance with a prescribed transfer function which has a given bandwidth and whose Fourier transform has a given time duration T. Said fingers are divided into a plurality of N finger groups designed identical to one another with respect to the number fingers n and corresponding finger spacings of corresponding fingers. Each finger group has a length in a propagation direction of the acoustic wave in the filter which is at least equal to the mean wavelength .lambda..sub.o. Center spacings of adjacent finger groups from one another are non-equidistant in accordance with the prescribed transfer function.

Abstract: The present invention is directed to an improved electromagnetic relay having means for eliminating the chatter or bounce of the relay armature upon the movement of the relay armature from its energized position to its rest position, that is, the releasing or returning movement of the relay armature. An armature stopping means is formed by two resilient strips which deflect in response to the returning movement of the relay armature. This deflection of these resilient strips stores energy in these resilient strips for returning the relay armature to its initial rest position. In addition to these two resilient strips, the armature stopping means of the present invention includes means for generating independent counter forces which oppose the deflection of these resilient strips. One of these counter forces is a frictional force generated by the abuttment of a bent flange forming part of each of the resilient strips against rigid mounting elements for mounting the two resilient strips.