US3801934A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter for binary pulse signals
Assignee: US Philips Corp
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Filing: 1972-10-12
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Granted: 1974-04-02
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Expires: 1992-10-12
Abstract
Abstract In a transversal filter for binary pulse signals provided with a shift register whose elements are connected through weighting networks to a combination network, exact zero points of the amplitude-versus-frequency characteristics are realized in spite of a relatively low number of shift register elements and associated weighting networks. At least two sets of weighting networks for forming transfer functions of alike shape, and each limiting the pulse spectrum in its bandwidth are connected to the shift register while corresponding weighting networks in adjacent sets of weighting networks are separated from one another by a prescribed number of shift register elements and the output signals from the different sets of weighting networks are combined in the combination network.
Inventors
- 👤 Gerwen P Van
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 08:35
CPC Classifications
H; H03; H03H; H03H17/00; H03H17/02; H03H17/06
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
218 words
A filter for binary pulse signals derived from a separate signal source controlled by a clock pulse generator, which filter is provided with a shift register connected to the signal source and having a number of shift register elements whose contents are shifted by a shift pulse generator connected to the shift register at a shift frequency which is equal to a multiple of the clock frequency, the shift register elements being connected through weighting networks to a combination network, characterized in that of the successive shift register elements a first group of k successive shift register elements is connected to a first set of weighting networks for forming a first transfer function H( omega ) limiting the pulse spectrum in its bandwidth, and furthermore at least a second group of k successive shift register elements is connected to a second set of weighting networks for forming a second transfer function D.H( omega ) which is similar to the first transfer function where D is a constant, corresponding weighting networks of the different sets being separated from one another by V shift register elements, the output signals from the weighting networks of the different sets being combined in the combination networks so as to suppress the components of the pulse spectrum at suitable posItions in the transmission band.
Claim 2
Dependent Claim
218 words
A filter for binary pulse signals derived from a separate signal source controlled by a clock pulse generator, which filter is provided with a shift register connected to the signal source and having a number of shift register elements whose contents are shifted by a shift pulse generator connected to the shift register at a shift frequency which is equal to a multiple of the clock frequency, the shift register elements being connected through weighting networks to a combination network, characterized in that of the successive shift register elements a first group of k successive shift register elements is connected to a first set of weighting networks for forming a first transfer function H( omega ) limiting the pulse spectrum in its bandwidth, and furthermore at least a second group of k successive shift register elements is connected to a second set of weighting networks for forming a second transfer function D.H( omega ) which is similar to the first transfer function where D is a constant, corresponding weighting networks of the different sets being separated from one another by V shift register elements, the output signals from the weighting networks of the different sets being combined in the combination networks so as to suppress the components of the pulse spectrum at suitable posItions in the transmission band.
Claim 3
Dependent Claim
137 words
A filter as claimed in claim 1, in which a number of (X+1) sets of weighting network is connected to the shift register for forming a series of similar transfer functions Dx.H( omega ), the sets going from the input of the shift register to the output being enumerated in accordance with the series X/2, X/2-1, . . . . , 2, 1, 0, -1, -2, . . . . , -X/2+1, X/2 and Dx being the constant associated with the set enumerated x in this series, characterized in that for the suppression of spectrum components at positions in the transmission band which are independent of the values of the constants Dx, the constants Dx having even indices x are equal to zero and the constant Dx having odd indices x satisfy the relation D x Dx.
Claim 4
Dependent Claim
129 words
A filter as claimed in claim 1, in which a number of (X+1) sets of weighting networks is connected to the shift register for forming a series of similar transfer functions Dx.H( omega ), the sets going from the input of the shift register to its output being enumerated in accordance with the series X/2, X/2-1, . . . . , 2, 1, 0, -1, -2, . . . . , -X/2+1, X/2 and Dx being the constant associated with the set enumerated x in this series, characterized in that for suppressing the spectrum components at positions in the transmission band which are independent of the values of the constants Dx, the constant Do is equal to zero and the other constants Dx satisfy the relation D x -Dx.
Claim 5
Dependent Claim
103 words
A filter as claimed in claim 2, characterized in that for forming a transfer function which varies between the desired suppression positions in the transmission band substantially in accordance with the said transfer function H( omega ) limiting the pulse spectrum in its bandwidth the constants Dx satisfy the relation Dx (1 - x/1+X/2).D''x where D''x represents the coefficients in the Fourier series development of a transfer function whose zero points coincide with the said suppression positions and whose value between its zero points is constant, which constant has the same value, but an opposite sign in adjacent intervals between successive zero points.
Claim 6
Dependent Claim
69 words
A filter as claimed in claim 1 characterized in that for filtering analog signals the signal source connected to the shift register is provided with an analog-to-digital converter which converts the analog signal to be filtered into a pulse series characterizing said signal, said pulse series being applied to the shift register while furthermore a digital-to-analog converter is arranged in cascade with the analog-to-digital converter and the shift register.
Claim 7
Dependent Claim
104 words
A filter as claimed in claim 3, characterized in that for forming a transfer function which varies between the desired suppression positions in the transmission band substantially in accordance with the said transfer function H( omega ) limiting the pulse spectrum in its bandwidth the constants Dx satisfy the relation Dx (1 x/ 1+X/2) .D''x where D''x represents the coefficients in the Fourier series development of a transfer function whose zero points coincide with the said suppression positions and whose value between its zero points is constant, which constant has the same value, but an opposite sign in adjacent intervals between successive zero points.
References Cited (Backward Citations)
GB1168154A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-04-01 | 1977-10-01 | 1978-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-01 | 1981-10-01 | 1982-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-01 | 1985-10-01 | 1986-04-02 | $7700.00 | Window Closed / Lapsed |