Abstract: Multi-dimensional digital filters have such a circuit structure that their transfer function corresponds to that of an antimetrical filter, and have a characteristic function that is a rational function of the squares of the equivalent complex frequencies. Multi-dimensional filters, wave digital filters as well, can thereby be realized having a closed attenuation behavior.

Abstract: The invention relates to a filter for electric signals consisting of switches, capacitors and amplifiers, wherein at least one switch is designed in the manner of voltage reversal switches such that the voltage at the switch terminals, subsequent to activation of the switch, is equally great in amount, but oppositely directed relative to the voltage prior to actuation of the switch. It is the object of the invention to utilize, in such filter circuits, electronic components which are as simple as possible and to fashion their design as freely as possible. In accordance with the invention this object is achieved by virtue of the fact that the voltage connected to the switch terminals (11, 12), in a first clock pulse phase (1), is intermediately stored via a first amplifier (V1) on a capacitor (C.sub.s), and, in a second clock pulse phase (2), via a second amplifier (V2), this voltage is again impressed in inverted form on the switch terminals (11, 12). (FIGS. 1, 3, 4).

Abstract: A method for digital frequency conversion of audio signals or PCM signals into signals of a frequency-division multiplex system in which the original signals exist in a channel of limited band width. All channels are brought into their desired frequency ranges through simplified multiplication processes, using a basic operating rate having a frequency of six times the channel band width.

Abstract: In one illustrative embodiment, a filter circuit for discrete signals is provided corresponding in filter function to an analog ladder structure containing inductive and capacitive components. The reactive components of the analog filter structure are realized in the filter circuit as one-port and two-port elements having time delay, while nonreactive components of the analog filter are realized as time-delay-free one-port and plural-port elements.

Abstract: A wave digital filter comprising at least one filter section without delay elements, each port thereof having a positive port admittance, and the signal quantities therein being operated upon, preferably within certain individual multiport adaptors of the filter section, in such a way that the pseudo power, ##EQU1## RECEIVED BY RESPECTIVE ADAPTOR PORTS V OF PORT ADMITTANCE G.sub.v and associated with input quantities a.sub.v (t.sub.m) and output quantities b.sub.v (t.sub.m) at respective operating times t.sub.m, is equal to or preferably only slightly greater than the value of the pseudo power function p (t.sub.m) which is obtained by omitting rounding or truncating, respectively, or overflow of the numbers being processed, and instead carrying out arithmetic operations precisely.

Abstract: In one illustrative embodiment, a basic filter circuit for discrete signals is provided corresponding in filter function to an analog ladder network containing inductive and capacitive components. The reactive components of the analog filter structure are realized in the basic filter circuit as one-port and two-port elements having time delay, while non-reactive components of the analog filter are realized as time-delay-free one-port and plural-port elements.