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Patent US3999047A successfully refreshed from Google Patents.
US3946337A
Expired / Lapsed
US
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Phase modulator for phase shift key communications systems
Assignee: Bendix Corp
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Filing: 1975-04-25
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Granted: 1976-03-23
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Expires: 1995-04-25
Abstract
Abstract A carrier wave is directed through a voltage controlled phase shifter to a load. A sample of the signal at the output of the voltage controlled phase shifter is selectably applied, in accordance with modulation information, through one of a plurality of transmission line phase shifters to a phase detector which also receives a sample of the carrier wave. The resulting phase detector output signal is applied through a low pass filter to control the voltage controlled phase shifter.
Inventors
- 👤 William D. Philips
- 👤 William H. Franklin, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:47
CPC Classifications
H; H03; H03C; H03C3/00; H03C3/10; H03C3/12; H03C3/22
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
155 words
A phase modulator comprising means for generating a raw carrier frequency; means responsive to a control signal for shifting the phase of said raw carrier frequency to produce a phase shifted carrier frequency; at least first and second means, a signal applied to said first means being shifted a predetermined number of electrical degrees with respect to a signal applied to said second means; switch means for applying a sample of said phase shifted carrier frequency to one of said first and second means and subsequently to the other of said first and second means in accordance with information to be conveyed by said phase shifted carrier frequency; phase detector means for generating an output signal related to the phase difference between said raw carrier frequency and the signal from said first and second means; and, low pass filter means responsive to said output signal for generating the control signal for said means for shifting.
Claim 2
Dependent Claim
155 words
A phase modulator comprising means for generating a raw carrier frequency; means responsive to a control signal for shifting the phase of said raw carrier frequency to produce a phase shifted carrier frequency; at least first and second means, a signal applied to said first means being shifted a predetermined number of electrical degrees with respect to a signal applied to said second means; switch means for applying a sample of said phase shifted carrier frequency to one of said first and second means and subsequently to the other of said first and second means in accordance with information to be conveyed by said phase shifted carrier frequency; phase detector means for generating an output signal related to the phase difference between said raw carrier frequency and the signal from said first and second means; and, low pass filter means responsive to said output signal for generating the control signal for said means for shifting.
Claim 3
Dependent Claim
30 words
The phase modulator of claim 1 wherein said means for shifting comprises a voltage conrolled phase shifter continuously producing said carrier frequency phase shifted in accordance with said control signal.
Claim 4
Dependent Claim
61 words
The phase modulator of claim 2 wherein said first means comprises a first transmission line means and said second means comprises a second transmission line means, each of said first and second transmission line means having respectively a quarter wavelength transmission line section having first ends connected together and second ends connectable through said switch means to a signal return terminal.
Claim 5
Dependent Claim
24 words
The phase modulator of claim 3 wherein said low pass filter means comprises an operational amplifier connected as an active amplifier low pass filter.
Claim 6
Dependent Claim
38 words
The phase modulator of claim 2 wherein at least one of said first and second means comprises a length of transmission line having a predetermined phase shift therethrough to a signal having the frequency of said carrier frequency.
References Cited (Backward Citations)
US2923891A
Cited
US3454904A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-03-23 | 1979-09-22 | 1980-03-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-03-23 | 1983-09-22 | 1984-03-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-03-23 | 1987-09-22 | 1988-03-23 | $7700.00 | Window Closed / Lapsed |