US5148128A
Expired / Lapsed
US
⏱️ 0.0 years remaining
RF digital phase shift modulators
Assignee: Raytheon Co
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Filing: 1991-10-25
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Granted: 1992-09-15
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Expires: 2011-10-25
Abstract
Abstract A BPSK (Binary-Phase-Shift-Keying) modulator having reduced amplitude and phase errors includes two non-ideal N°-bit phase shifters disposed between two 3 dB quadrature couplers to perform out-of-phase combining. When the two phase bits are alternately switched between a reference state and a signal state being N° out of phase with respect to the reference by the cancellation, a 180° binary phase shift keying modulator having reduced amplitude and phase errors relative to the individual phase shifters is provided.
Inventors
- 👤 Shamsur R. Mazumder
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 10:15
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/18; H04L27/20; H04L27/2032; H04L27/2053; H04L27/2057
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
126 words
An RF digital phase shift modulator comprising: first quadrature hybrid means, having amplitude and phase characteristics for providing first and second signal paths having a differential phase shift of substantially 90°; first phase shifting means, disposed in said first signal path for providing a selectable different phase shift characteristic to said first signal path; second phase shifting means, disposed in said second signal path for providing a selectable differential phase shift characteristic to said second signal path; and second quadrature hybrid means, having amplitude and phase characteristics substantially the same as said amplitude and phase characteristics of said first quadrature hybrid coupled to said first and second signal paths for combining said first and second signal paths with a differential phase shift of substantially 90° therebetween.
Claim 2
Dependent Claim
126 words
An RF digital phase shift modulator comprising: first quadrature hybrid means, having amplitude and phase characteristics for providing first and second signal paths having a differential phase shift of substantially 90°; first phase shifting means, disposed in said first signal path for providing a selectable different phase shift characteristic to said first signal path; second phase shifting means, disposed in said second signal path for providing a selectable differential phase shift characteristic to said second signal path; and second quadrature hybrid means, having amplitude and phase characteristics substantially the same as said amplitude and phase characteristics of said first quadrature hybrid coupled to said first and second signal paths for combining said first and second signal paths with a differential phase shift of substantially 90° therebetween.
Claim 3
Dependent Claim
63 words
The digital modulator as recited in claim 1 wherein said first and second phase shifting means, have substantially the same amplitude and phase characteristics to provide in response to a first pair of control signals a differential phase shift of 0° and N°, respectively, and in response to a second pair of control signals a differential phase shift of N° and 0°, respectively.
Claim 4
Dependent Claim
24 words
The digital modulator as recited in claim 2 wherein said first quadrature hybrid means and second quadrature hybrid means are quadrature hybrid directional couplers.
Claim 5
Dependent Claim
19 words
The digital modulator as recited in claim 3 wherein said first and second differential phase shifts (N°) are 180°.
Claim 6
Dependent Claim
19 words
The digital modulator as recited in claim 4 wherein said directional couplers have coupling values of approximately 3 decibels.
Claim 7
Dependent Claim
114 words
An RF phase shift keyed digital modulator comprising: a first quadrature coupler having amplitude and phase characteristics providing, first and second signal paths having a differential phase shift of substantially 90°; a first phase shifter disposed in said first signal path for providing a selectable differential phase shift; a second phase shifter disposed in said second signal path for providing a selectable differential phase shift; and a second quadrature coupler having amplitude and phase characteristics substantially the same as said amplitude and phase characteristics of said first quadrature coupler, coupled to said first and second signal paths for combining said first and second signal paths with a differential phase shift of substantially 90° therebetween.
Claim 8
Dependent Claim
114 words
An RF phase shift keyed digital modulator comprising: a first quadrature coupler having amplitude and phase characteristics providing, first and second signal paths having a differential phase shift of substantially 90°; a first phase shifter disposed in said first signal path for providing a selectable differential phase shift; a second phase shifter disposed in said second signal path for providing a selectable differential phase shift; and a second quadrature coupler having amplitude and phase characteristics substantially the same as said amplitude and phase characteristics of said first quadrature coupler, coupled to said first and second signal paths for combining said first and second signal paths with a differential phase shift of substantially 90° therebetween.
Claim 9
Dependent Claim
62 words
The digital modulator as recited in claim 6 wherein said first and second phase shifters have substantially the same amplitude and phase characteristics to provide in response to a first par of control signal as differential phase shift of 0° and N°, respectively, and in response to a second pair of control signals a differential phase shift of N° and 0°, respectively.
Claim 10
Dependent Claim
19 words
The digital modulator as recited in claim 7 wherein said first and second differential phase shifts N are 180°.
Claim 11
Dependent Claim
18 words
The digital modulator as recited in claim 8 wherein said first and second quadrature couplers are Lange couplers.
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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) | 1995-09-15 | 1996-03-16 | 1996-09-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-09-15 | 2000-03-16 | 2000-09-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-09-15 | 2004-03-16 | 2004-09-15 | $7700.00 | Window Closed / Lapsed |