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US3976958A
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R-C signal dividers and signal filters
Assignee: AT&T Inc
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Filing: 1975-03-27
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Granted: 1976-08-24
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Expires: 1995-03-27
Abstract
Abstract A class of signal dividers and signal filters is disclosed comprising first and second wavepaths coupled at one end to a common input port and at their other ends to a summing network to form a sum signal, and to a differencing network to form a differencing signal. Phase shift means are included along at least one wavepath for producing a differential phase shift between signals in said two wavepaths. In order that such devices be capable of operation at very low frequencies (i.e., a few Hertz), be physically small, and be capable of being made by means of integrated circuit techniques, the phase shifters are made solely of R-C passive elements, or of other devices that can be readily integrated.
Inventors
- 👤 Harold Seidel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:13
CPC Classifications
H; H03; H03H; H03H11/00; H03H11/02; H03H11/04; H03H11/12; H03H11/1217; H03H11/16; H03H11/36; H03H7/00; H03H7/18
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
75 words
A signal divider comprising: first and second wavepaths coupled at one end to a common input port and at their other ends to a summing network to form a sum signal, and to a differencing network to form a difference signal; and phase shift means whose passive elements consist of resistive and capacitive elements disposed along at least one of said wavepaths for producing a nonlinear differential phase shift between signals in said two wavepaths.
Claim 2
Dependent Claim
75 words
A signal divider comprising: first and second wavepaths coupled at one end to a common input port and at their other ends to a summing network to form a sum signal, and to a differencing network to form a difference signal; and phase shift means whose passive elements consist of resistive and capacitive elements disposed along at least one of said wavepaths for producing a nonlinear differential phase shift between signals in said two wavepaths.
Claim 3
Dependent Claim
29 words
The signal divider according to claim 1 wherein first phase shift means are located in said first wavepath, and second phase shift means are located in said second wavepath.
Claim 4
Dependent Claim
47 words
The signal divider according to claim 2 wherein said sum signal is proportional to cos(Θ-α/2), and the difference signal is proportional to sin(Θ-α/2), where Θ is the phase shift through said first phase shift means, and α is the phase shift through said second phase shift means.
Claim 5
Dependent Claim
45 words
The signal divider according to claim 1 wherein the ratio Γ(p) of said sum signal and said difference is given by the ratio of an even order polynomial E(p) and an odd order polynomial O(p), where p = iω, and ω is the angular frequency.
Claim 6
Dependent Claim
53 words
The signal divider according to claim 4 wherein the roots of the transmission function T 1 (p) of said first phase shifter, and the negative of the roots of the transmission function T 2 (p) of said second phase shifter constitute all of the roots of the equation 1 + Γ(p) = 0.
Claim 7
Dependent Claim
15 words
The signal divider according to claim 1 wherein said phase shift means includes active elements.
Claim 8
Dependent Claim
75 words
A signal divider comprising: first and second all-pass transversal equalizers having nonlinear phase shift characteristics Θ(p) and α(p), respectively; the input end of each of said equalizers being coupled to a common input port; the other output end of each of said equalizers being coupled to a summing network to form a sum signal, and to a differencing network to form a difference signal; said sum difference signals constituting the output signals from said divider.
Claim 9
Dependent Claim
75 words
A signal divider comprising: first and second all-pass transversal equalizers having nonlinear phase shift characteristics Θ(p) and α(p), respectively; the input end of each of said equalizers being coupled to a common input port; the other output end of each of said equalizers being coupled to a summing network to form a sum signal, and to a differencing network to form a difference signal; said sum difference signals constituting the output signals from said divider.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-24 | 1980-02-23 | 1980-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-24 | 1984-02-23 | 1984-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-24 | 1988-02-23 | 1988-08-24 | $7700.00 | Window Closed / Lapsed |