Patent US3711773A successfully refreshed from Google Patents.
US3711773A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Phase jitter meter
Assignee: Hekimian Laboratories Inc
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Filing: 1970-07-09
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Granted: 1973-01-16
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Expires: 1990-07-09
Abstract
Abstract A system is disclosed for monitoring short term amplitude and phase variations and measuring average and peak-to-peak phase jitter experienced by a test signal transmitted through a system under test. Phase detection is achieved with an exclusive OR gate which compares the phase of the test signal with that of a reference signal provided by a voltage-controlled oscillator (VCO), and provides an output signal having a frequency twice that of the test signal and a duty cycle proportional to test signal phase displacement. This output signal is converted to a DC signal which, in addition to serving as a basis for measurement of the average and peak-to-peak phase jitter of the test signal, controls the phase of the VCO to thereby phase lock the reference signal to the test signal. Short term amplitude variations experienced by the test signal are compared against an adjustable predetermined range in order to provide an indication whenever the amplitude is outside the selected range. A novel test signal generator is also disclosed using a modified Hartley oscillator configuration to provide an output signal having high amplitude and frequency stability independently of the type of transistor employed.
Inventors
- 👤 N Hekimian
- 👤 J Kelly
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:27
CPC Classifications
G; G01; G01R; G01R25/00
Claims Analysis
Total Claims: 27
Claim 1
Independent Claim
267 words
A system for monitoring the phase of an input signal having a predetermined frequency, said system comprising: a voltage-controlled oscillator for providing a reference signal having a nominal frequency equal to said predetermined frequency and having a phase which is nominally displaced from the input signal phase by 90* and is variable in response to the amplitude of a control signal applied thereto; means for converting said input signal and said reference signal to respective square waves alternating between first and second amplitude levels; an exclusive OR gate, arranged to receive said input signal and said reference signal square waves, for providing an output square wave having a first polarity when said input signal and reference signal square waves are at different amplitude levels and having a second polarity when said input signal and reference signal square waves are at the same amplitude levels, whereby the duty cycle of said output square wave is proportional to the degree of phase displacement between said input and reference signals; means for converting said output square wave to an output signal having an amplitude proportional to the duty cycle of said output square wave; control means for phase-locking said reference signal to said input signal, said control means including means for applying said output signal as a control signal to said voltagecontrolled oscillator; first and second counter means; means responsive to amplitude excursion of said output signal above a pre-established threshold level for incrementing said first counter means; and means responsive to amplitude excursions of said input signal outside a predetermined range of amplitudes for incrementing said second counter means.
Claim 2
Independent Claim
267 words
A system for monitoring the phase of an input signal having a predetermined frequency, said system comprising: a voltage-controlled oscillator for providing a reference signal having a nominal frequency equal to said predetermined frequency and having a phase which is nominally displaced from the input signal phase by 90* and is variable in response to the amplitude of a control signal applied thereto; means for converting said input signal and said reference signal to respective square waves alternating between first and second amplitude levels; an exclusive OR gate, arranged to receive said input signal and said reference signal square waves, for providing an output square wave having a first polarity when said input signal and reference signal square waves are at different amplitude levels and having a second polarity when said input signal and reference signal square waves are at the same amplitude levels, whereby the duty cycle of said output square wave is proportional to the degree of phase displacement between said input and reference signals; means for converting said output square wave to an output signal having an amplitude proportional to the duty cycle of said output square wave; control means for phase-locking said reference signal to said input signal, said control means including means for applying said output signal as a control signal to said voltagecontrolled oscillator; first and second counter means; means responsive to amplitude excursion of said output signal above a pre-established threshold level for incrementing said first counter means; and means responsive to amplitude excursions of said input signal outside a predetermined range of amplitudes for incrementing said second counter means.
Claim 3
Dependent Claim
40 words
The system according to claim 1 further comprising: third counter means; and means responsive to simultaneous excursions of said input signal outside said predetermined range and of said output signal above said pre-established threshold for incrementing said third counter means.
Claim 4
Dependent Claim
49 words
The system according to claim 2 further comprising: means responsive to input signal amplitude reductions on the order of at least 15 db lasting for a time period at least equal to a multiplicity of input signal cycles for inhibiting incrementation of said first, second and third counter means.
Claim 5
Dependent Claim
25 words
The system according to claim 3 further comprising fourth counter means and means responsive to each said amplitude reductions for incrementing said fourth counter means.
Claim 6
Dependent Claim
50 words
The system according to claim 1 further comprising test signal generator means for providing a test signal at said predetermined frequency to be transmitted through a signal transmission channel under test, the test signal thus transmitted comprising said input signal, said test signal generator being integrally packaged with said system.
Claim 7
Dependent Claim
162 words
The system according to claim 5 wherein said test signal generator comprises a modified Hartley oscillator configuration, including: a bipolar transistor having collector-emitter and base electrodes; a source of supply voltage; means for applying said supply voltage to said collector; a current limiting resistor connected in the collector-emitter path of said transistor; a tuned tank circuit including a choke having a centeR tap and one end connected to a reference potential; means for connecting said center tap to said collector-emitter circuit on the emitter side of said transistor; means for coupling the other end of said choke to the base of said transistor, said means for coupling including a diode poled to conduct current in opposition to base current in said transistor; and means for establishing a dc bias for said base independently of current flow through said diode, said dc bias being such to render said transistor conductive in the absence of any effects from said tank circuit and said diode.
Claim 8
Independent Claim
343 words
A system for monitoring the phase of an input signal having a predetermined frequency, said system comprising: a voltage-controlled oscillator for providing a reference signal having a nominal frequency equal to said predetermined frequency and having a phase which is nominally displaced from the input signal phase by 90* and is variable in response to the amplitude of a control signal applied thereto; means for converting said input signal and said reference signal to respective square waves alternating between first and second amplitude levels; an exclusive OR gate, arranged to receive said input signal and said reference signal square waves, for providing an output square wave having a first polarity when said input signal and reference signal square waves are at different amplitude levels and having a second polarity when said input signal and reference signal square waves are at the same amplitude levels, whereby the duty cycle of said output square wave is proportional to the degree of phase displacement between said input and reference signals; means for converting said output square wave to an output signal having an amplitude proportional to the duty cycle of said square wave; control means for phase-locking said reference signal to said input signal, said control means including means for applying said output signal as a control signal to said voltage-controlled oscillator; further means for monitoring short term amplitude variations of said input signal outside a predetermined range of amplitudes, said further means including: means for integrating said input signal to provide an integrated signal having an amplitude representing the average amplitude of said input signal; amplifier means for amplifying said integrated signal by a predetermined amplification factor greater than one; a string of series-connected resistors; means for applying said amplified integrated signal to one end of said string of resistors; means for connecting the other end of said string of resistors to a source of reference potential; and means for picking-off a pair of voltages from said string of resistors to establish said predetermined range of amplitudes about said average amplitude of said input signal.
Claim 9
Independent Claim
343 words
A system for monitoring the phase of an input signal having a predetermined frequency, said system comprising: a voltage-controlled oscillator for providing a reference signal having a nominal frequency equal to said predetermined frequency and having a phase which is nominally displaced from the input signal phase by 90* and is variable in response to the amplitude of a control signal applied thereto; means for converting said input signal and said reference signal to respective square waves alternating between first and second amplitude levels; an exclusive OR gate, arranged to receive said input signal and said reference signal square waves, for providing an output square wave having a first polarity when said input signal and reference signal square waves are at different amplitude levels and having a second polarity when said input signal and reference signal square waves are at the same amplitude levels, whereby the duty cycle of said output square wave is proportional to the degree of phase displacement between said input and reference signals; means for converting said output square wave to an output signal having an amplitude proportional to the duty cycle of said square wave; control means for phase-locking said reference signal to said input signal, said control means including means for applying said output signal as a control signal to said voltage-controlled oscillator; further means for monitoring short term amplitude variations of said input signal outside a predetermined range of amplitudes, said further means including: means for integrating said input signal to provide an integrated signal having an amplitude representing the average amplitude of said input signal; amplifier means for amplifying said integrated signal by a predetermined amplification factor greater than one; a string of series-connected resistors; means for applying said amplified integrated signal to one end of said string of resistors; means for connecting the other end of said string of resistors to a source of reference potential; and means for picking-off a pair of voltages from said string of resistors to establish said predetermined range of amplitudes about said average amplitude of said input signal.
Claim 10
Dependent Claim
117 words
The system according to claim 7 further comprising: first and second differential amplifiers, each having first and second signal input terminals and an output terminal for providing a predetermined signal when the signal amplitude at said first input terminal exceeds the signal amplitude at said second input terminal; means for applying said input signal to said first signal input terminal of said first differential amplifier and to said second signal input of said second differential amplifier; means for applying the larger of said pair of voltages to said second input terminal of said first differential amplifier; and means for applying the smaller of said pair of voltages to the first input terminal of said second differential amplifier.
Claim 11
Dependent Claim
50 words
The system according to claim 8 wherein said amplification factor is two, and further comprising double-pole switch means connected to said string of resistors for permitting selection of amplitude ranges of + or - 6 db and + or - 3 db, about said average amplitude of said input signal.
Claim 12
Independent Claim
290 words
A system for monitoring the phase of aN input signal having a predetermined frequency, said system comprising: a voltage-controlled oscillator for providing a reference signal having a nominal frequency equal to said predetermined frequency and having a phase which is nominally displaced from the input signal phase by 90* and is variable in response to the amplitude of a control signal applied thereto; means for converting said input signal and said reference signal to respective square waves alternating between first and second amplitude levels; an exclusive OR gate, arranged to receive said input signal and said reference signal square waves, for providing an output square wave having a first polarity when said input signal and reference signal square waves are at different amplitude levels and having a second polarity when said input signal and reference signal square waves are at the same amplitude levels, whereby the duty cycle of said output square wave is proportional to the degree of phase displacement between said input and reference signals; means for converting said output square wave at an output signal having an amplitude proportional to the duty cycle of said output square wave; control means for phase-locking said reference signal to said input signal, said control means including means for applying said output signal as a control signal to said voltage-controlled oscillator; a high pass filter, arranged to receive said output signal from said means for converting, for providing a filtered signal from which the dc component of said output signal is removed, the amplitude of said filtered signal varying in response to instantaneous phase differences between said input and reference signals; and monitoring means for providing a measurement signal having an amplitude proportional to a specified parameter of said filtered signal.
Claim 13
Independent Claim
290 words
A system for monitoring the phase of aN input signal having a predetermined frequency, said system comprising: a voltage-controlled oscillator for providing a reference signal having a nominal frequency equal to said predetermined frequency and having a phase which is nominally displaced from the input signal phase by 90* and is variable in response to the amplitude of a control signal applied thereto; means for converting said input signal and said reference signal to respective square waves alternating between first and second amplitude levels; an exclusive OR gate, arranged to receive said input signal and said reference signal square waves, for providing an output square wave having a first polarity when said input signal and reference signal square waves are at different amplitude levels and having a second polarity when said input signal and reference signal square waves are at the same amplitude levels, whereby the duty cycle of said output square wave is proportional to the degree of phase displacement between said input and reference signals; means for converting said output square wave at an output signal having an amplitude proportional to the duty cycle of said output square wave; control means for phase-locking said reference signal to said input signal, said control means including means for applying said output signal as a control signal to said voltage-controlled oscillator; a high pass filter, arranged to receive said output signal from said means for converting, for providing a filtered signal from which the dc component of said output signal is removed, the amplitude of said filtered signal varying in response to instantaneous phase differences between said input and reference signals; and monitoring means for providing a measurement signal having an amplitude proportional to a specified parameter of said filtered signal.
Claim 14
Dependent Claim
58 words
The system according to claim 10 wherein said monitoring means comprises: rectifier means for full wave rectifying said filter signal; and average jitter detection means responsive to the full wave rectified and filtered signal for providing a dc signal having an amplitude corresponding to the average value of the amplitude of said full wave rectified and filtered signal.
Claim 15
Dependent Claim
34 words
The system according to claim 11 further comprising peak-to-peak jitter detection means for providing a further dc signal having an amplitude proportional to the peak-to-peak amplitude of said full wave rectified and filtered signal.
Claim 16
Dependent Claim
46 words
The system according to claim 10 wherein said monitoring means comprises: rectifier means for full wave rectifying said filtered signal; and peak-to-peak jitter detection means for providing a dc signal having an amplitude proportional to the peak-to-peak amplitude of said full wave rectified and filtered signal.
Claim 17
Independent Claim
258 words
A system for monitoring the phase of an input signal having a predetermined frequency, said system comprising: a voltage-controlled oscillator for providing a reference signal having a nominal frequency equal to said predetermined frequency and having a phase which is nominally displaced from the input signal phase by 90* and is variable in response to the amplitude of a control signal applied thereto; means for converting said input signal and said reference signal to respective square waves alternating between first and second amplitude levels; an exclusive OR gate, arranged to receive said input signal and said reference signal square waves, for providing an output square wave having a first polarity when said input signal and reference signal square waves are at different amplitude levels and having a second polarity when said input signal and reference signal square waves are at the same amplitude levels, whereby the duty cycle of said output square wave is proportional to the degree of phase displacement between said input and reference signals; means for converting said output square wave to an output signal having an amplitude pRoportional to the duty cycle of said output square wave; control means for phase-locking said reference signal to said input signal, said control means including means for applying said output signal as a control signal to said voltage-controlled oscillator; a counter; and means responsive to each input signal amplitude reduction on the order of at least 15 db lasting for a time period at least equal to a multiplicity of input signal cycles for incrementing said counter.
Claim 18
Independent Claim
258 words
A system for monitoring the phase of an input signal having a predetermined frequency, said system comprising: a voltage-controlled oscillator for providing a reference signal having a nominal frequency equal to said predetermined frequency and having a phase which is nominally displaced from the input signal phase by 90* and is variable in response to the amplitude of a control signal applied thereto; means for converting said input signal and said reference signal to respective square waves alternating between first and second amplitude levels; an exclusive OR gate, arranged to receive said input signal and said reference signal square waves, for providing an output square wave having a first polarity when said input signal and reference signal square waves are at different amplitude levels and having a second polarity when said input signal and reference signal square waves are at the same amplitude levels, whereby the duty cycle of said output square wave is proportional to the degree of phase displacement between said input and reference signals; means for converting said output square wave to an output signal having an amplitude pRoportional to the duty cycle of said output square wave; control means for phase-locking said reference signal to said input signal, said control means including means for applying said output signal as a control signal to said voltage-controlled oscillator; a counter; and means responsive to each input signal amplitude reduction on the order of at least 15 db lasting for a time period at least equal to a multiplicity of input signal cycles for incrementing said counter.
Claim 19
Independent Claim
274 words
A system for counting phase variations of at least a predetermined magnitude and subsisting for at least a predetermined time interval in an input signal of known frequency, said system comprising: a voltage-controlled oscillator for providing a reference signal having a nominal frequency equal to said predetermined frequency and having a phase which is nominally displaced from the input signal phase by 90* and is variable in response to the amplitude of a control signal applied thereto; means for converting said input signal and said reference signal to respective square waves alternating between first and second amplitude levels; an exclusive OR gate, arranged to receive said input signal and said reference signal square waves, for providing an output square wave having a first polarity when said input signal and reference signal square waves are at different amplitude levels and having a second polarity when said input signal and reference signal square waves are at the same amplitude levels, whereby the duty cycle of said output square wave is proportional to the degree of phase displacement between said input and reference signals; means for converting said output square wave to an output signal having an amplitude proportional to the duty cycle of said output square wave; control means for phase-locking said reference signal to said input signal, said control means including means for applying said output signal as a control signal to said voltage-controlled oscillator; means for establishing a reference signal of constant amplitude; a phase hit counter; and means responsive to said reference signal and said output signal for incrementing said counter each time the amplitude of said output signal exceeds said constant amplitude.
Claim 20
Independent Claim
274 words
A system for counting phase variations of at least a predetermined magnitude and subsisting for at least a predetermined time interval in an input signal of known frequency, said system comprising: a voltage-controlled oscillator for providing a reference signal having a nominal frequency equal to said predetermined frequency and having a phase which is nominally displaced from the input signal phase by 90* and is variable in response to the amplitude of a control signal applied thereto; means for converting said input signal and said reference signal to respective square waves alternating between first and second amplitude levels; an exclusive OR gate, arranged to receive said input signal and said reference signal square waves, for providing an output square wave having a first polarity when said input signal and reference signal square waves are at different amplitude levels and having a second polarity when said input signal and reference signal square waves are at the same amplitude levels, whereby the duty cycle of said output square wave is proportional to the degree of phase displacement between said input and reference signals; means for converting said output square wave to an output signal having an amplitude proportional to the duty cycle of said output square wave; control means for phase-locking said reference signal to said input signal, said control means including means for applying said output signal as a control signal to said voltage-controlled oscillator; means for establishing a reference signal of constant amplitude; a phase hit counter; and means responsive to said reference signal and said output signal for incrementing said counter each time the amplitude of said output signal exceeds said constant amplitude.
Claim 21
Dependent Claim
32 words
The system according to claim 15 further comprising timing means for actuating said phase hit counter for a specified time interval and inhibiting incrementation of said phase hit counter at other times.
Claim 22
Dependent Claim
28 words
The system according to claim 15 further comprising: a sensory-perceptible indicator; means for actuating said indicator each time the amplitude of said output signal exceeds said constant amplitude.
Claim 23
Dependent Claim
78 words
The system according to claim 15 further comprising: a high pass filter, arranged to receive said output signal from said means for converting, for providing a filtered signal from which the dc component of said output signal is removed, the amplitude of said filtered signal varying in response to instantaneous phase differences between said input and reference signals; and monitoring means for providing a measurement signal having an amplitude proportional to a specified parameter of said filtered signal.
Claim 24
Dependent Claim
58 words
The system according to claim 18 wherein said monitoring means comprises: rectifier means for full wave rectifying said filter signal; and average jitter detection means responsive to the full wave rectified and filtered signal for providing a dc signal having an amplitude corresponding to the average value of the amplitude of said full wave rectified and filtered signal.
Claim 25
Dependent Claim
46 words
The system according to claim 18 wherein said monitoring means comprises: rectifier means for full wave rectifying said filtered signal; and peak-to-peak jitter detection means for providing a dc signal having an amplitude proportional to the peak-to-peak amplitude of said full wave rectified and filtered signal.
Claim 26
Dependent Claim
132 words
The system according to claim 15 comprising further means for monitoring short term amplitude variations of said input signal outside a predetermined range of amplitudes, said further means including: means for integrating said input signal to provide an integrated signal having an amplitude representing the average amplitude of said input signal; amplifier means for amplifying said integrated signal by a predetermined amplification factor greater than one; a string of series-connected resistors; means for applying said amplified integrated signal to one end of said string of resistors; means for connecting the other end of said string of resistors to a source of reference potential; and means for picking-off a pair of voltages from said string of resistors to o establish said predetermined range of amplitudes about said average amplitude of said input signal.
Claim 27
Dependent Claim
117 words
The system according to claim 21 further comprising: first and second differential amplifiers, each having first and second signal input terminals and an output terminal for providing a predetermined signal when the signal amplitude at said first input terminal exceeds the signal amplitude at said second input terminal; means for applying said input signal to said first signal input terminal of said first differential amplifier and to said second signal input of said second differential amplifier; means for applying the larger of said pair of voltages to said second input terminal of said first differential amplifier; and means for applying the smaller of said pair of voltages to the first input terminal of said second differential amplifier.
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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) | 1976-01-16 | 1976-07-17 | 1977-01-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-16 | 1980-07-17 | 1981-01-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-16 | 1984-07-17 | 1985-01-16 | $7700.00 | Window Closed / Lapsed |