# US 4,393,356 A · Filter circuit for electric waves

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- Number: US 4,393,356 A
- Document ID: US4393356A
- Status: Granted
- Kind: A
- Application number: 06/151,772
- Filed: 1980-05-21
- Granted: 1983-07-12
- Earliest claimed: 1974-11-12
- Assignees: Siemens Aktiengesellschaft
- Inventors: Friedrich L. Kuenemund
- Web page: https://patentgrep.com/patent/US4393356A

## CPC

- H10D 84/891: {characterised by the integration of only components covered by H10D44/00, e.g. integration of charge-coupled devices [CCD] or charge injection devices [CID}
- H01P 1/20: Frequency-selective devices, e.g. filters
- H03H 15/02: using analogue shift registers
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H01P: WAVEGUIDES; RESONATORS, LINES, OR OTHER DEVICES OF THE WAVEGUIDE TYPE (operating at optical frequencies G02B)
- H03H: IMPEDANCE NETWORKS, e.g. RESONANT CIRCUITS; RESONATORS (waveguides, resonators, lines or other devices of the waveguide type H01P)

## Abstract

A filter circuit for electrical waves including at least one line which supplies electrical input waves and at least one line for withdrawing output electrical waves and in which the frequency dependent transmission characteristic is determined by coupled line loops each of which is in the form of a line ring and wherein coupling between the line loops is unidirectional and the individual line loops are designed so that they have unidirectional transmission characteristics.

## Claims

### Claim 1

An electrical filter comprising, input and output lines having pairs of input and output terminals, a first charge coupled device having a plurality of charge storage cells each of a first charge storage capacity with its input connected to one input terminal of said input line and its output connected to the other input terminal of said input line, a pulse generator producing "n" phase related pulse trains at a certain frequency and supplying inputs to said charge storage cells of said first charge coupled device to move charges therethrough, a second charge coupled device having a plurality of charge storage cells each of said first charge storage capacity with its input connected to one output terminal of said output line and its output connected to the other output terminal of said output line, a pulse generator producing "n" phase related pulse trains at a certain frequency and supplying inputs to said cells of said second charge coupled device to move charges therethrough, a first non-directional coupling element coupled to an intermediate storage cell of said first charge coupled device, a second non-directional coupling element coupled to an intermediate storage cell of said second charge coupled device, a third charge coupled device having a plurality of charge storage cells of different or the same storage capacity as the storage cells of said first and second charge coupled devices with its output connected to its input, a pulse generator producing "n" phase related pulse trains at a certain frequency and supplying inputs to said cells of said third charge coupled device to move charges therethrough, one of the storage cells of said third charge coupled device coupled to said first non-directional coupling element and another of the storage cells of said third charge coupled device coupled to said second non-directional coupling element.

### Claim 2

An electrical filter comprising, input and output lines having pairs of input and output terminals, a first bucket brigade device having a plurality of charge storage cells each of a first charge storage capacity with its input connected to one input terminal of said input line and its output connected to the other input terminal of said input line, a pulse generator producing "n" phase related pulse trains at a certain frequency and supplying inputs to said charge storage cells of said first bucket brigade device to move charges therethrough, a second bucket brigade device having a plurality of charge storage cells each of said first charge storage capacity with its input connected to one output terminal of said output line and its output connected to the other output terminal of said output line, a pulse generator producing "n" phase related pulse trains at a certain frequency and supplying inputs to said cells of said second bucket brigade device to move charges therethrough, a first non-directional coupling element coupled to an intermediate storage cell of said first bucket brigade device, a second non-directional coupling element coupled to an intermediate storage cell of said second bucket brigade device, a third bucket brigade device having a plurality of charge storage cells of different or the same storage capacity as the storage cells of said first and second bucket brigade devices with its output connected to its input, a pulse generator producing "n" phase related pulse trains at a certain frequency and supplying inputs to said cells of said third bucket brigade device to move charges therethrough, one of the storage cells of said third bucket brigade device coupled to said first non-directional coupling element and another of the storage cells of said third bucket brigade device coupled to said second non-directional coupling element.

### Claim 3 (depends on 1)

An electrical filter according to claim 1 wherein said first and second non-directional coupling elements are resistors.

### Claim 4 (depends on 2)

An electrical filter according to claim 2 wherein said first and second non-directional coupling elements are resistors.

### Claim 5 (depends on 1)

An electrical filter according to claim 1 wherein said first and second non-directional coupling elements are capacitors.

### Claim 6 (depends on 2)

An electrical filter according to claim 2 wherein said first and second non-directional coupling elements are capacitors.