US4866649A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Multi-dimensional digital filter having adders, multipliers and shift elements
Assignee: Siemens AG
•
Filing: 1987-11-03
•
Granted: 1989-09-12
•
Expires: 2007-11-03
Abstract
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.
Inventors
- 👤 Alfred Fettweis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 18:09
CPC Classifications
H; H03; H03H; H03H17/00; H03H17/02; H03H17/0201
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
123 words
In a multi-dimensional digital wave filter having k dimensions, said filter being formed of circuit means composed of logic elements such as adders, multipliers, and shift elements, the combination comprising; circuit means having a transfer function corresponding to that of an antimetrical filter and having a characteristic function that is a rational function of the squares of the equivalent complex frequencies Ψ I , where i equals 1 . . . k, said circuit means having the real transfer functions of a multi-dimensional, complex all-pass filter, said circuit means including means for forming the complex all-pass transfer function as a product of complex individual-pass functions in only one frequency variable (Ψ I ), and input and output terminals connected to said circuit means.
Claim 2
Dependent Claim
123 words
In a multi-dimensional digital wave filter having k dimensions, said filter being formed of circuit means composed of logic elements such as adders, multipliers, and shift elements, the combination comprising; circuit means having a transfer function corresponding to that of an antimetrical filter and having a characteristic function that is a rational function of the squares of the equivalent complex frequencies Ψ I , where i equals 1 . . . k, said circuit means having the real transfer functions of a multi-dimensional, complex all-pass filter, said circuit means including means for forming the complex all-pass transfer function as a product of complex individual-pass functions in only one frequency variable (Ψ I ), and input and output terminals connected to said circuit means.
Claim 3
Dependent Claim
52 words
Digital filter according to claim 1, including means for ensuring that the relationship S*.sub.i (ψ*.sub.i)=jS.sub.i (1/ψ.sub.i),i=1 . . . k holds for at least one of the individual all-pass functions S i (ψ i ); the asterisk (*) denoting the transition to the complex conjugate value and j denoting the imaginary unit.
References Cited (Backward Citations)
US3967099A
Cited
US4061905A
Cited
US3919671A
Cited
US3980872A
Cited
US4020333A
Cited
US4326288A
Cited
US4356464A
Cited
US4236224A
Cited
US4760542A
Cited
US4736392A
Cited
EP0240820A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-09-11 | 1993-03-13 | 1993-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-09-11 | 1997-03-13 | 1997-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-09-11 | 2001-03-13 | 2001-09-12 | $7700.00 | Window Closed / Lapsed |