US3859599A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Signal acquisition network for signal reception
Assignee: RCA Licensing Corp
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Filing: 1972-12-20
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Granted: 1975-01-07
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Expires: 1992-12-20
Abstract
Abstract The present invention relates to a signal acquisition network comprising an automatic phase/frequency control network suitable for automatic fine tuning with a wide frequency scanning feature, operative during signal acquisition. Wide frequency scanning is provided by a self quenching oscillator, which provides a low frequency ''''dithering'''' voltage to the AP/FC network to facilitate signal acquisition. The arrangement permits one to combine a large capture bandwidth with accurate narrow band tuning after ''''lock in''''. The invention is suitable for FM and TV application, and may be fabricated using integrated circuit techniques.
Inventors
- 👤 William Peil
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:54
CPC Classifications
H; H03; H03J; H03J7/00; H03J7/02; H03J7/04; H03J7/08; H03J7/10; H03D; H03D1/00; H03D1/22; H03D1/2245
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
181 words
A signal acquisition network for use in a reception system comprising: a. a first oscillator having a predetermined latent forward gain and oscillating at a given low frequency, b. an automatic phase/frequency control network comprising: 1. a second, voltage controlled oscillator 2. means coupling the output of said first oscillator to said second oscillator to cause the frequency of the latter to swing over a range exceeding the lock-in range of said control network for signal acquisition, and 3. a detector to the input of which a signal being acquired is applied and whose output is coupled to said first and said second oscillators, said detector developing an error signal to maintain said second oscillator and said signal in proper phase relationship for demodulation once lock-in has occurred, and said detector quenching said first oscillator once lock-in has occurred by coupling thereto demodulated oscillations of said first oscillator in degenerative phase, said control network, when said signal exceeds a minimum low level, exhibiting a gain at said first oscillator frequency at the detector output in excess of said latent forward gain.
Claim 2
Dependent Claim
181 words
A signal acquisition network for use in a reception system comprising: a. a first oscillator having a predetermined latent forward gain and oscillating at a given low frequency, b. an automatic phase/frequency control network comprising: 1. a second, voltage controlled oscillator 2. means coupling the output of said first oscillator to said second oscillator to cause the frequency of the latter to swing over a range exceeding the lock-in range of said control network for signal acquisition, and 3. a detector to the input of which a signal being acquired is applied and whose output is coupled to said first and said second oscillators, said detector developing an error signal to maintain said second oscillator and said signal in proper phase relationship for demodulation once lock-in has occurred, and said detector quenching said first oscillator once lock-in has occurred by coupling thereto demodulated oscillations of said first oscillator in degenerative phase, said control network, when said signal exceeds a minimum low level, exhibiting a gain at said first oscillator frequency at the detector output in excess of said latent forward gain.
Claim 3
Dependent Claim
36 words
means coupling the output of said first oscillator to said second oscillator to cause the frequency of the latter to swing over a range exceeding the lock-in range of said control network for signal acquisition, and
Claim 4
Dependent Claim
36 words
means coupling the output of said first oscillator to said second oscillator to cause the frequency of the latter to swing over a range exceeding the lock-in range of said control network for signal acquisition, and
Claim 5
Dependent Claim
51 words
A signal acquisition network as set forth in claim 1 wherein said first oscillator is a harmonic oscillator having a lead RC phase shift network and a lag RC phase shift network for establishing the resonant frequency at the point at which the phase shifts are equal and opposite in sign.
Claim 6
Dependent Claim
15 words
a positive feedback connection from said output electrode to a first input electrode and wherein
Claim 7
Dependent Claim
15 words
a positive feedback connection from said output electrode to a first input electrode and wherein
Claim 8
Dependent Claim
67 words
the time constants of said respective phase shift networks are adjusted so that the higher gain region from said lag network and one plateau from said lead network producing higher gain are superimposed for maximum oscillator gain at said resonant frequency and wherein the other plateau from said lead network lies on the low frequency side of said resonance frequency reducing amplifier gain below said resonant frequency.
Claim 9
Dependent Claim
67 words
the time constants of said respective phase shift networks are adjusted so that the higher gain region from said lag network and one plateau from said lead network producing higher gain are superimposed for maximum oscillator gain at said resonant frequency and wherein the other plateau from said lead network lies on the low frequency side of said resonance frequency reducing amplifier gain below said resonant frequency.
Claim 10
Dependent Claim
15 words
A signal acquisition network as set forth in claim 2 wherein said first oscillator has:
Claim 11
Dependent Claim
23 words
said lag RC network is coupled with said first input electrode and said lead RC network is coupled to said second input electrode.
Claim 12
Dependent Claim
23 words
said lag RC network is coupled with said first input electrode and said lead RC network is coupled to said second input electrode.
Claim 13
Dependent Claim
102 words
a detector to the input of which a signal being acquired is applied and whose output is coupled to said first and said second oscillators, said detector developing an error signal to maintain said second oscillator and said signal in proper phase relationship for demodulation once lock-in has occurred, and said detector quenching said first oscillator once lock-in has occurred by coupling thereto demodulated oscillations of said first oscillator in degenerative phase, said control network, when said signal exceeds a minimum low level, exhibiting a gain at said first oscillator frequency at the detector output in excess of said latent forward gain.
Claim 14
Dependent Claim
102 words
a detector to the input of which a signal being acquired is applied and whose output is coupled to said first and said second oscillators, said detector developing an error signal to maintain said second oscillator and said signal in proper phase relationship for demodulation once lock-in has occurred, and said detector quenching said first oscillator once lock-in has occurred by coupling thereto demodulated oscillations of said first oscillator in degenerative phase, said control network, when said signal exceeds a minimum low level, exhibiting a gain at said first oscillator frequency at the detector output in excess of said latent forward gain.
Claim 15
Dependent Claim
11 words
A signal acquisition network as set forth in claim 3 wherein
Claim 16
Dependent Claim
64 words
A signal acquisition network as set forth in claim 4 wherein the break of said lag network and the higher frequency break of said lead network are closely spaced about resonance so that the phase response of said lag network has a significant slope while the phase response of said lead network has a significant slope of opposite sign at resonanCe for frequency stability.
Claim 17
Dependent Claim
36 words
A signal acquisition network as set forth in claim 5 wherein said oscillator has a gain from d.c. to near resonance which remains close to but less than unity to insure that the oscillator remains quenched.
Claim 18
Dependent Claim
176 words
A signal acquisition network as set forth in claim 6 wherein said gain element is a first transistor whose base, emitter and collector electrodes are said first input, second input and output electrodes, respectively; wherein said positive feedback connection provides an output current at an output terminal balancing the emitter current of said first transistor, and contains a second transistor of a complementary conduction type, said second transistor (Q2) having base, emitter and collector electrodes, said base electrode being coupled to the collector of said first transistor; wherein said lag RC network comprises a first resistance (R4) and a capacitor (C1) connected in series between said output terminal and ground, and a second resistance (R2 + R3) connected to said output terminal and in shunt for a.c. with said series elements; and wherein said lead RC network comprises a first resistance (R1) and a capacitor (C4) connected in series between the emitter of said first transistor (Q1) and ground, and a second emitter connected resistance (R8) in shunt for a.c. with said last recited series elements.
Claim 19
Dependent Claim
109 words
A signal acquisition network as set forth in claim 7 wherein said detector is a synchronous detector and includes a Q demodulator in a four quadrant multiplier configuration having two pairs of output collectors at which complementary AFC voltages appear; and wherein said emitter electrode of said first transistor (Q1) is coupled to one collector pair through said first emitter connected resistance (R1) and wherein said output terminal is coupled to said other collector pair through said first output terminal connected resistance (R4) to share bias current between said oscillator and said Q demodulator; and wherein said lag capacitor (C1) has a value suitable for low frequency AFC filtering.
Claim 20
Dependent Claim
64 words
A signal acquisition network as set forth in claim 8 wherein said lead capacitor (C4) has a large value in relation to said lag capacitor, to reduce the magnitude of the swing of said first oscillator output at the other collector pair in relation to that at said one collector pair, both said RC networks providing high frequency AFC filtering at said collector pairs.
Claim 21
Dependent Claim
100 words
A signal acquisition network as set forth in claim 9 wherein said positive feedback connection contains a third transistor (Q3) of high Beta of the same conduction type as said first transistor (Q1) having base, emitter and collector electrodes and having its base connected to the collector of said second transistor, its collector coupled to the emitter of said second transistor, and its emitter coupled to said output terminal; and wherein said second resistance (R2 + R3) coupled to said output terminal has a tap coupled to the base electrode of said first transistor for providing said regenerative feedback connection.
Claim 22
Dependent Claim
30 words
A signal acquisition network as set forth in claim 9 wherein said second oscillator is a high frequency oscillator for converting said signal to an intermediate frequency for synchronous detection.
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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) | 1978-01-06 | 1978-07-08 | 1979-01-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-01-06 | 1982-07-08 | 1983-01-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-01-06 | 1986-07-08 | 1987-01-07 | $7700.00 | Window Closed / Lapsed |