US4990867A
Expired / Lapsed
US
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Modulator
Assignee: Toshiba Corp
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Filing: 1990-05-10
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Granted: 1991-02-05
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Expires: 2010-05-10
Abstract
Abstract In a modulator for converting two digital signals of I channel and Q channel in base band into analog signals and for converting a component of the signals whose phase is the same as a carrier and another component of the signals whose phase is orthogonal to the carrier so as to produce an orthogonally modulated wave, the two digital signals are connected to one signal train by time-sharing and multiplexing them and the converted analog signals are separated to two analog signals for the I channel and the Q channel and thereby a digital modulator can be structured by using only one digital/analog converter resulting in reducing the adjustment points and the production cost.
Inventors
- 👤 Koji Ogura
- 👤 Mutsumu Serizawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:10
CPC Classifications
H; H04; H04L; H04L27/00; H04L27/18; H04L27/20; H04L27/2032; H04L27/2053; H04L27/206; H04L27/2067; H04L27/2071
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
122 words
In a modulator for converting two digital signals for an I channel and a Q channel in the base band into analog signals and for modulating a component of the signals whose phase is the same as a carrier and another component of the signals whose phase is orthogonal to the carrier, comprising: signal connection means for connecting the two signals of said I channel and said Q channel to one signal train by time-sharing and multiplexing them; a digital/analog converter for converting a signal connected by said signal connection means into a analog signal; and signal separation means for separating an output analog signal converted by said digital/analog converter to two analog signals of said I channel and said Q channel.
Claim 2
Dependent Claim
122 words
In a modulator for converting two digital signals for an I channel and a Q channel in the base band into analog signals and for modulating a component of the signals whose phase is the same as a carrier and another component of the signals whose phase is orthogonal to the carrier, comprising: signal connection means for connecting the two signals of said I channel and said Q channel to one signal train by time-sharing and multiplexing them; a digital/analog converter for converting a signal connected by said signal connection means into a analog signal; and signal separation means for separating an output analog signal converted by said digital/analog converter to two analog signals of said I channel and said Q channel.
Claim 3
Dependent Claim
34 words
The modulator according to claim 1 wherein a sampling points in the base band of said digital signals are offset between a time axis of said I channel and that of said Q channel.
Claim 4
Dependent Claim
38 words
The modulator according to claim 1 wherein said signal connection means causes said adjacent signal trains to be grounded for a particular time period when connecting the two signals to one signal train by time-sharing and multiplexing them.
Claim 5
Dependent Claim
33 words
The modulator according to claim 1 wherein a digital signal processing section is provided at least for mapping and filtering signals, said signal connection means being accommodated in said digital signal process section.
Claim 6
Dependent Claim
49 words
The modulator according to claim 1 wherein a digital signal processing section is provided at least for mapping and filtering signals, said digital signal processing section and at least one of said signal connection means, said digital/analog converter, and said signal separation means being accommodated in the same LSI.
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) | 1994-02-04 | 1994-08-06 | 1995-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-02-04 | 1998-08-06 | 1999-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-02-04 | 2002-08-06 | 2003-02-05 | $7700.00 | Window Closed / Lapsed |