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US4663583A
Expired / Lapsed
US
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Automatically variable phase characteristic all-pass circuit
Assignee: Nokia Bell Labs
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Filing: 1986-05-27
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Granted: 1987-05-05
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Expires: 2006-05-27
Abstract
Abstract An automatically variable all-pass circuit includes a variable impedance circuit for changing the shape of the phase characteristic of the output signal of the all-pass circuit as a function of the amplitude of the output signal of the circuit.
Inventors
- 👤 John J. Ludwick
- 👤 Edward S. Parsons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 03:10
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/14; H04B3/146; H04B3/148; H03; H03H; H03H11/00; H03H11/02; H03H11/16; H03H11/18
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
96 words
An automatically variable phase control circuit comprising an all-pass circuit including means for receiving an input signal and producing an output signal that is phase shifted from the input signal; a variable impedance circuit; means responsive to the output signal for applying control signals to the variable impedance circuit and changing the magnitude of the variable impedance as a function of the amplitude of the output signal; and the all-pass circuit being responsive to the magnitude of the variable impedance for changing automatically its phase characteristic as a function of the amplitude of the output signal.
Claim 2
Dependent Claim
96 words
An automatically variable phase control circuit comprising an all-pass circuit including means for receiving an input signal and producing an output signal that is phase shifted from the input signal; a variable impedance circuit; means responsive to the output signal for applying control signals to the variable impedance circuit and changing the magnitude of the variable impedance as a function of the amplitude of the output signal; and the all-pass circuit being responsive to the magnitude of the variable impedance for changing automatically its phase characteristic as a function of the amplitude of the output signal.
Claim 3
Dependent Claim
59 words
An automatic phase control circuit in accordance with claim 1 wherein the all-pass circuit is an active circuit configuration, the variable impedance circuit includes at least two junction field-effect transistors having their drain-to-source paths interconnected in a parallel circuit arrangement, and the control signals are applied between the gate electrodes of the junction field-effect transistors and a reference voltage.
Claim 4
Dependent Claim
48 words
An automatic phase control circuit in accordance with claim 2 wherein the two junction field-effect transistors of the variable impedance circuit include a first junction field-effect transistor having a minimum drain-to-source impedance R and a second junction field-effect transistor having a minimum drain-to-source impedance of at least 2R.
Claim 5
Dependent Claim
55 words
An automatic phase control circuit in accordance with claim 3 further comprising means for receiving different magnitude signals between the respective gate electrodes and the reference voltage, the magnitude of the signal applied to the second junction field-effect transistor being at least twice the magnitude of the signal applied to the first junction field-effect transistor.
Claim 6
Dependent Claim
55 words
An automatic phase control circuit in accordance with claim 2 further comprising means for receiving different magnitude signals between the respective gate electrodes and the reference voltage, the magnitude of the signal applied to the second junction field-effect transistor being at least twice the magnitude of the signal applied to the first junction field-effect transistor.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-05-04 | 1990-11-03 | 1991-05-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-05-04 | 1994-11-03 | 1995-05-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-05-04 | 1998-11-03 | 1999-05-05 | $7700.00 | Window Closed / Lapsed |