US3660607A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus and method for detecting phase deviation of a pilot subcarrier in stereophonic multiplex broadcasting
Assignee: Tesla AS
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Filing: 1970-04-01
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Granted: 1972-05-02
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Expires: 1990-04-01
Abstract
Abstract Method and apparatus for detecting both the magnitude and direction of any deviation in the pilot-subcarrier wave by conventionally separating the pilot carrier, regenerating and shifting its resultant signal by 90* and comparing it with a signal derived from the multiplex signal to produce a signal indicative of the magnitude of deviation. Simultaneously a reference signal is obtained from the original multiplex signal which is in phase with the comparison signal. The deviation signal and the reference signal are then demodulated to produce a directional voltage.
Inventors
- 👤 Zdenek Mack
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 02:37
CPC Classifications
H; H04; H04H; H04H20/00; H04H20/44; H04H20/46; H04H20/47; H04H20/48
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
165 words
Apparatus for measuring and detecting the magnitude and direction of phase deviation of a pilot-subcarrier wave of a stereophonic multiplex signal comprising, means for regenerating said pilot-subcarrier means for shifting the phase of said regenerated subcarrier 90*, a band-pass filter and a phasedetector serially arranged therewith, said band-pass filter receiving said multiplex signal, said phase-detector receiving said shifted subcarrier signal, said phase-detector producing a signal indicative of the magnitude of phase deviation of said pilot-subcarrier, a first low-pass filter receiving said phase deviation signal, a balanced demodulator receiving said signal from said low-pass filter, a second and third low-pass filter serially arranged with respect to each other, said second lowpass filter having a low frequency characteristic and receiving a signal from said multiplex signal, the third low-pass filter having a frequency characteristic identical with said first lowpass filter and passing its output signal to said balanced demodulator and an indicator receiving the output of said balanced demodulator whereby the direction of said pilotsubcarrier is indicated.
Claim 2
Dependent Claim
165 words
Apparatus for measuring and detecting the magnitude and direction of phase deviation of a pilot-subcarrier wave of a stereophonic multiplex signal comprising, means for regenerating said pilot-subcarrier means for shifting the phase of said regenerated subcarrier 90*, a band-pass filter and a phasedetector serially arranged therewith, said band-pass filter receiving said multiplex signal, said phase-detector receiving said shifted subcarrier signal, said phase-detector producing a signal indicative of the magnitude of phase deviation of said pilot-subcarrier, a first low-pass filter receiving said phase deviation signal, a balanced demodulator receiving said signal from said low-pass filter, a second and third low-pass filter serially arranged with respect to each other, said second lowpass filter having a low frequency characteristic and receiving a signal from said multiplex signal, the third low-pass filter having a frequency characteristic identical with said first lowpass filter and passing its output signal to said balanced demodulator and an indicator receiving the output of said balanced demodulator whereby the direction of said pilotsubcarrier is indicated.
Claim 3
Dependent Claim
52 words
The apparatus according to claim 1 wherein the balanced demodulator comprises an invertor, and a pair of summing circuits, said invertor producing a pair of signals fed respectively to said summing circuits, the output of one of said first and third low-pass filters being simultaneously fed to each of said summing circuits.
Claim 4
Dependent Claim
28 words
The apparatus according to claim 2 including a rectifier connected to each of said summing circuits, said rectifiers being unipolar and connected across the terminals of said indicator.
Claim 5
Dependent Claim
38 words
The apparatus according to claim 2 including a rectifier connected to each of said summing circuits, said rectifiers being of different polarity and connected together to one terminal of said indicator, the other terminal of which is grounded.
Claim 6
Dependent Claim
27 words
The apparatus according to claim 2, wherein said invertor is connected to said third low-pass filter and said first low-pass filter is connected to said summing circuits.
Claim 7
Dependent Claim
27 words
The apparatus according to claim 2 wherein said invertor is connected to said first low-pass filter and said third low-pass filter is connected to said summing circuits.
Claim 8
Independent Claim
116 words
The method of measuring and detecting the magnitude and direction of phase deviation of a pilot-subcarrier wave of stereophonic multiplex signal comprising the steps of separating said pilot-carrier wave from said multiplex signal, regenerating said pilot-carrier signal, shifting the phase of said regenerated signal 90* and comparing said shifted regenerated signal with a comparison signal derived from said original multiplex signal to obtain a difference signal indIcative of the phase deviation of said pilot-carrier wave, simultaneously obtaining a reference signal derived from said original multiplex signal, said reference signal being in phase therewith, demodulating said difference signal and said reference signal to obtain a voltage thereby indicative of the phase direction of said regenerated pilot-subcarrier signal.
Claim 9
Independent Claim
116 words
The method of measuring and detecting the magnitude and direction of phase deviation of a pilot-subcarrier wave of stereophonic multiplex signal comprising the steps of separating said pilot-carrier wave from said multiplex signal, regenerating said pilot-carrier signal, shifting the phase of said regenerated signal 90* and comparing said shifted regenerated signal with a comparison signal derived from said original multiplex signal to obtain a difference signal indIcative of the phase deviation of said pilot-carrier wave, simultaneously obtaining a reference signal derived from said original multiplex signal, said reference signal being in phase therewith, demodulating said difference signal and said reference signal to obtain a voltage thereby indicative of the phase direction of said regenerated pilot-subcarrier signal.
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) | 1975-05-02 | 1975-11-01 | 1976-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-02 | 1979-11-01 | 1980-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-02 | 1983-11-01 | 1984-05-02 | $7700.00 | Window Closed / Lapsed |