US3745255A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Receiver with an improved phase lock loop in a multichannel telemetry system with suppressed carrier
Assignee: Individual
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Filing: 1971-08-18
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Granted: 1973-07-10
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Expires: 1991-08-18
Abstract
Abstract A phase lock loop is disclosed for a receiver in a two-channel PSK/PM telemetry system with a suppressed carrier. The receiver inphase channel output is filtered by first and second bandpass filters and the receiver quadrature channel output is filtered by third and fourth bandpass filters. The first and third filters have the same bandwidth, centered about the frequency of one subcarrier and is wide enough to pass data around the first harmonic of the subcarrier. The second and fourth bandpass filters have the same bandwidth centered about the frequency of the other subcarrier and is wide enough to pass data around the first harmonic of this subcarrier. The outputs of the first and third filters are mixed in one mixer and the outputs of the second and fourth filters are mixed in another mixer. The outputs of the two mixers are weighted to produce a weighted sum signal which is supplied to the loop filter.
Inventors
- 👤 J Fletcher
- 👤 S Butman
- 👤 U Timor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:11
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/02; H04L5/12
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
202 words
In a receiver of a multichannel telemetry system of the type in which data in separate channels phase modulate separate subcarriers and signals of the phase modulated subcarriers are transmitted by a transmitter to the receiver for data detection on a suppressed carrier, a phase lock loop arrangement compris1ng: an input terminal at which the signal received from said transmitter is applied; a variable oscillator for providing an output signal at a frequency which is a function of an input signal supplied thereto; first mixing means for mixing the signal at said input terminal with the oscillator''s output signal; phase shifting means for shifting the phase of the oscillator output signal by 90*; second mixing means for mixing the signal at said input terminal with the output signal of said phase shifting means; a loop filter for controlling the input signal to said oscillator; and control means for controlling the input signal to said loop filter as a function of the outputs of said first and second mixing means, said control means including at least two bandpass filters centered at the frequency of one of said subcarriers and at least two bandpass filters centered at the frequency of another of said subcarriers.
Claim 2
Dependent Claim
202 words
In a receiver of a multichannel telemetry system of the type in which data in separate channels phase modulate separate subcarriers and signals of the phase modulated subcarriers are transmitted by a transmitter to the receiver for data detection on a suppressed carrier, a phase lock loop arrangement compris1ng: an input terminal at which the signal received from said transmitter is applied; a variable oscillator for providing an output signal at a frequency which is a function of an input signal supplied thereto; first mixing means for mixing the signal at said input terminal with the oscillator''s output signal; phase shifting means for shifting the phase of the oscillator output signal by 90*; second mixing means for mixing the signal at said input terminal with the output signal of said phase shifting means; a loop filter for controlling the input signal to said oscillator; and control means for controlling the input signal to said loop filter as a function of the outputs of said first and second mixing means, said control means including at least two bandpass filters centered at the frequency of one of said subcarriers and at least two bandpass filters centered at the frequency of another of said subcarriers.
Claim 3
Dependent Claim
75 words
The arrangement as recited in claim 1 wherein the number of channels is N, and said control means includes 2N bandpass filters, each two filters being centered at the frequency of a subcarrier of a different of said N channels, said control means further including means responsive to the outputs of said 2N filters for generating N control signals and means utilizing said N control signals for providing said input signal to said loop filter.
Claim 4
Dependent Claim
74 words
The arrangement as recited in claim 1 wherein said control means include first and second bandpass filters for filtering the output of said first mixing means and third and fourth bandpass filters for filtering the output of said second mixing means, said first and third bandpass filters being centered at the freqUency of one of said subcarriers and said second and fourth bandpass filters being centered at the frequency of another of said subcarriers.
Claim 5
Dependent Claim
36 words
The arrangement as recited in claim 3 wherein said control means include output means utilizing the outputs of said first, second, third and fourth bandpass filters for providing a control input signal to said loop filter.
Claim 6
Dependent Claim
65 words
The arrangement as recited in claim 3 wherein said control means include third mixing means for mixing the outputs of said first and third bandpass filters, and fourth mixing means for mixing the outputs of said second and fourth bandpass filters, and output means responsive to the outputs of said third and fourth mixing means for providing the control input signal to said loop filter.
Claim 7
Dependent Claim
47 words
The arrangement as recited in claim 5 wherein said output means include means for weighting the outputs of said third and fourth mixing means and for summing the weighted outputs of said third and fourth mixing means to provide the control input signal to said loop filter.
Claim 8
Dependent Claim
176 words
In a receiver of a two-channel phase shift keying phase modulation telemetry system in which data is transmitted to a receiver as a signal including phase modulated first and second subcarriers of different frequencies, a phase lock loop comprising: a loop filter; a voltage controlled oscillator for providing an output signal as a function of the voltage signal from said loop filter; a 90* phase shifter for shifting the oscillator output signal by 90*; first and second mixer for mixing the received signal with the oscillator output signal and with the output of the phase shifter, respectively; first and second bandpass filters for filtering the output of said first mixer; third and fourth bandpass filters for filtering the output of said second mixer, each of said first and third bandpass filters having substantially the same bandwidth and each of said second and fourth bandpass filters having substantially the same bandwidth; and control means for controlling the input to said loop filter as a function of the outputs of said first, second, third and fourth bandpass filters.
Claim 9
Dependent Claim
176 words
In a receiver of a two-channel phase shift keying phase modulation telemetry system in which data is transmitted to a receiver as a signal including phase modulated first and second subcarriers of different frequencies, a phase lock loop comprising: a loop filter; a voltage controlled oscillator for providing an output signal as a function of the voltage signal from said loop filter; a 90* phase shifter for shifting the oscillator output signal by 90*; first and second mixer for mixing the received signal with the oscillator output signal and with the output of the phase shifter, respectively; first and second bandpass filters for filtering the output of said first mixer; third and fourth bandpass filters for filtering the output of said second mixer, each of said first and third bandpass filters having substantially the same bandwidth and each of said second and fourth bandpass filters having substantially the same bandwidth; and control means for controlling the input to said loop filter as a function of the outputs of said first, second, third and fourth bandpass filters.
Claim 10
Dependent Claim
51 words
The arrangement as recited in claim 7 wherein the bandwidth of said first and third bandpass filters definable as Wa is centered about the frequency of said first subcarrier and the bandwidth of said second and fourth bandpass filters definable as Wb is centered about the frequency of said second subcarrier.
Claim 11
Dependent Claim
45 words
The arrangement as recited in claim 8 wherein Wa passes the data which phase modulated said first subcarrier around the first harmonic of the first subcarrier, and Wb passes the data which phase modulated said second subcarrier around the first harmonic of the second subcarrier.
Claim 12
Dependent Claim
51 words
The arrangement as recited in claim 9 wherein said control means include first means for combining the outputs of said first and third bandpass filters and the outputs of said second and fourth bandpass filters and second means for weighting the combination to provide the input signal to said loop filter.
Claim 13
Dependent Claim
41 words
The arrangement as recited in claim 10 wherein said first means comprise a third mixer for mixing the outputs of said first and third bandpass filters and a fourth mixer for mixing the outputs of said second and fourth bandpass filters.
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) | 1976-07-09 | 1977-01-08 | 1977-07-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-09 | 1981-01-08 | 1981-07-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-09 | 1985-01-08 | 1985-07-10 | $7700.00 | Window Closed / Lapsed |