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US3798573A
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Phase modulator using a frequency mixing process
Assignee: AT&T Inc
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Filing: 1973-03-16
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Granted: 1974-03-19
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Expires: 1993-03-16
Abstract
Abstract This application discloses a phase modulator comprising a plurality of phase shifters whose output are coupled to a frequency mixer. Carrier signals at different frequencies are applied to the phase shifters along with modulating signals derived from a common source. The resulting phase modulation impressed upon the output signal extracted from the mixer is related to the phases of the input signals to the mixer in the same way as the frequency of the output signal is related to the frequencies of the several input signals. This technique is used to synthesize specific phase functions. In particular, an arcsine function is generated using two varactor diode phase shifters.
Inventors
- 👤 H Seidel
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 09:21
CPC Classifications
H; H03; H03C; H03C7/00; H03C7/02; H03C7/025; H03C7/027; H03C3/00; H03C3/10; H03C3/12; H03C3/22
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
70 words
A phase modulator comprising: a plurality of phase shifters, each of which is asapted to operate at a different carrier signal frequency; means for applying a component of a common modulating signal to each of said phase shifters for varying the phase of the respective carrier signals; means for coupling the outputs from said phase shifters to a frequency mixer; and means for extracting an output signal from said mixer.
Claim 2
Dependent Claim
70 words
A phase modulator comprising: a plurality of phase shifters, each of which is asapted to operate at a different carrier signal frequency; means for applying a component of a common modulating signal to each of said phase shifters for varying the phase of the respective carrier signals; means for coupling the outputs from said phase shifters to a frequency mixer; and means for extracting an output signal from said mixer.
Claim 3
Dependent Claim
114 words
The phase modulator according to claim 1 wherein: the frequency omega 0 of said output signal is omega 0 + or - n omega 1 + or - m omega 2 . . . + or - p omega z; and wherein the phase of said output signal is theta + or -n theta 1 + or - theta 2 . . . p theta z; where omega 1, omega 2 . . . omega z are the frequencies of said carrier signals; theta 1, 2 . . . theta z are the phases of the output signals from said phase shifters and n, m, p . . . z are integers including zero.
Claim 4
Dependent Claim
60 words
The phase modulator according to claim 1 wherein each of said phase shifters comprises a multiport circulator and a varactor diode; and wherein a first port of said circulator constitutes the input port of said phase shifter; the varactor diode is connected to a second circulator port; and a third circulator port constitutes the output port of said phase shifter.
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) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |