Filter having frequency-dependent transmission properties for electric analog signals

Claim 2

A filter for discrete signals, a. said filter comprising a filter circuit operating on discrete signals and having a filter function for discrete signals corresponding to the frequency-dependent transmission properties for electric analog signals of an analog ladder structure having a predetermined configuration of interconnected analog components including at least three reactive analog components with respective impedance-representing constants; b. said filter circuit for discrete signals having a plurality of port elements including ports each with a port input and a port output terminal, at least certain of said plurality of port elements corresponding in filter function to reactive analog components of the analog ladder structure and such certain port elements comprising time delay means interposed between port input and output terminals thereof, each time delay means providing a time delay which is a function of a given time interval and being operable for receiving an input signal from an associated input terminal at a discrete time and for supplying an output signal to an associated output terminal at a discrete time thereafter in accordance with said time delay; the ports of said port elements being assigned port impedance numbers in accordance with the impedance-representing constants of the analog ladder structure corresponding thereto, and c. said filter circuit comprising interface device means having interface ports connected with the ports of said port elements and interconnecting the port elements in accordance with the configuration of said analog ladder structure, and said interface ports including sets of interface ports connecting with sets of port elements corresponding to sets of connected analog components of the analog ladder structure; d. the interface device means having interface circuitry including adder means and multiplier means connected with each of the sets of interface ports for interchange of signals with ports of the port elements connected with such interface ports, each such multiplier means having a multiplier coefficient correlated with the port impedance numbers of the respective ports of said port elements interchanging signals therewith.

Claim 3

A filter as claimed in claim 1, with said filter circuit for discrete signals having time delay means to prevent time-delay-free feedback loops via the interface circuitry.

Claim 4

A filter as claimed in claim 1 with each set of interface ports having a connective relationship therebetween via the associated interface circuitry in accordance with a parallel, series-parallel or series connection of the set of connected analog components of the analog ladder structure corresponding to the port elements connected with such set of interface ports, and each multiplier means having a multiplier coefficient correlated in accordance with voltage or current wave-flow relationships comprising a.sub.k = v.sub.k + R.sub.k i.sub.k and b.sub.k = v.sub.k - R.sub.k i.sub.k where the values of R k for each set of interface ports are positive and equal to the port impedance numbers of the associated set of port elements; where the value of v k and i k for each set of interface ports have the same relationships as the voltages and currents of the set of connected analog components of the analog ladder structure corresponding to the associated set of port elements; and where a k and b k represent the values of the discrete input and output signals at the interface ports of each set.

Claim 5

A filter as claimed in claim 1, with said filter circuit for discrete signals having a time-delay-free one-port element terminating said filter circuit and comprising a wave sink for realizing a resistance termination of the analog ladder structure.

Claim 6

A filter as claimed in claim 1, with said filter circuit for discrete signals having a time-delay-free one-port element connected as input thereto and comprising a wave source for realizing a voltage source for connection as input to the analog ladder structure.

Claim 7

A filter for discrete signals, a. said filter comprising a filter circuit operating on discrete signals and having a filter function for discrete signals corresponding to the frequency-dependent transmission properties for electric analog signals of an analog filter structure having a predetermined configuration of interconnected analog components comprising at least three interconnected reactive analog components with respective impedance-representing constants; b. said filter circuit for discrete signals having a plurality of port elements including ports each with a port input and a port output terminal, at least three of said plurality of port elements comprising reactive port elements corresponding in filter function to respective reactive analog components of the analog filter structure and such reactive port elements comprising time delay means interposed between port input and output terminals thereof, each time delay means providing a time delay which is a function of a given time interval and being operable for receiving an input signal from an associated input terminal at a discrete time and for supplying an output signal to an associated output terminal at a discrete time thereafter in accordance with said time delay; the ports of said port elements being assigned port impedance numbers in accordance with the impedance-representing constants of the analog components corresponding thereto, and c. said filter circuit comprising interface device means having interface ports connected with the ports of said port elements and interconnecting the port elements in accordance with the configuration of said analog filter structure, and said interface ports effectively including at least three sets of interface ports connecting with sets of port elements corresponding to sets of connected analog components of the analog filter structure; d. the interface device means having interface circuitry including adder means and multiplier means connected with each of the sets of interface ports for interchange of signals with ports of the port elements connected with such interface ports, each such multiplier means having a multiplier coefficient correlated with the port impedance numbers of the respective ports of said port elements interchanging signals therewith.

Claim 8

A filter for discrete signals, a. said filter comprising a filter circuit operating on discrete signals and having a filter function for discrete signals corresponding to the frequency-dependent transmission properties for electric analog signals of an analog filter structure having a predetermined configuration of interconnected analog components comprising at least three interconnected reactive analog components with respective impedance-representing constants; b. said filter circuit for discrete signals having a plurality of port elements including ports each with a port input and a port output terminal, at least three of said plurality of port elements comprising reactive port elements corresponding in filter function to respective reactive analog components of the analog filter structure and such reactive port elements comprising time delay means interposed between port input and output terminals thereof, each time delay means providing a time delay which is a function of a given time interval and being operable for receiving an input signal from an associated input terminal at a discrete time and for supplying an output signal to an associated output terminal at a discrete time thereafter in accordance with said time delay; the ports of said port elements being assigned port impedance numbers in accordance with the impedance-representing constants of the analog components corresponding thereto, and c. said filter circuit comprising interface device means having interface ports connected with the ports of said port elements and interconnecting the port elements in accordance with the configuration of said analog filter structure, and said interface ports effectively including at least three sets of interface ports connecting with sets of port elements corresponding to sets of connected analog components of the analog filter structure; d. the interface device means having interface circuitry including adder means and multiplier means connected with each of the sets of interface ports for interchange of signals with ports of the port elements connected with such interface ports, each such multiplier means having a multiplier coefficient correlated with the port impedance numbers of the respective ports of said port elements interchanging signals therewith.

Claim 9

A filter as claimed in claim 6, with said filter circuit for discrete signals having means preventing time-delay-free feedback loops via the interface circuitry.

Claim 10

A filter as claimed in claim 6 with each set of interface ports having a connective relationship therebetween via the associated interface circuitry in accordance with the type of connection of the set of connected analog components of the analog filter structure corresponding to the port elements connected with such set of interface ports, and each multiplier means having a multiplier coefficient correlated in accordance with voltge or current wave-flow relationships comprising a.sub.k = v.sub.k + R.sub.k i.sub.k and b.sub.k = v.sub.k - R.sub.k i.sub.k where the values of R k for each set of interface ports are equal to the port impedance numbers of the associated set of port elements; where the values of v k and i k for each set of interface ports have the same relationship as the voltages and currents of the set of connected analog components of the analog filter structure corresponding to the associated set of the port elements; and where a k and b k represent the values of the discrete input and output signals at the interface ports of each set.

Claim 11

A filter as claimed in claim 6, with said filter circuit for discrete signals having a time-delay-free one-port element terminating said filter circuit and comprising a wave sink for realizing a resistance termination of the analog filter structure.

Claim 12

A filter as claimed in claim 6, with said filter circuit for discrete signals having a time-delay-free one-port element connected as input thereto and comprising a wave source for realizing a voltage source for connection as input to the analog filter structure.

Claim 13

A filter as claimed in claim 6, with said filter circuit having at least three series-coupled time-delay-free multiport elements providing for transmission of discrete signals between each reactive port element and other of said port elements, said multiport elements each having at least three ports with respective terminals, and coupling means coupling respective terminals of the respective ports in series such that a terminal of one port for supplying signals is connected to a terminal of a next port for receiving signals.

Claim 14

A filter as claimed in claim 6 with said filter circuit comprising at least three interconnected multiport elements each having at least three ports and each of said multiport elements having at least one of said reactive port elements connected thereto.

Claim 15

A filter as claimed in claim 12, with said multiport elements each having a common port impedance number assigned to each of the ports thereof, at least one of said reactive port elements being a one-port element having a different port impedance number from the common port impedance number of the associated multiport element and the interface device means coupling such reactive port element with the associated multiport element comprising an interface device with multiplier means correlated as to multiplier coefficient with said common port impedance number and with a port impedance number equal to the port impedance number of said one-port element.