Patent US4561111A successfully refreshed from Google Patents.
US4561111A
Expired / Lapsed
US
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Method of predistorting a single sideband system
Assignee: Boeing North American Inc
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Filing: 1984-08-06
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Granted: 1985-12-24
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Expires: 2004-08-06
Abstract
Abstract A method of predistortion alignment of a single sideband transmission system in which the receiver becomes a part of the signal path which is predistorted, to providing improved overall intermodulation distortion. A convenient method of performing the alignment under field conditions is disclosed.
Inventors
- 👤 William A. Conner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 20:40
CPC Classifications
H; H04; H04B; H04B1/00; H04B1/68; H03; H03C; H03C1/00; H03C1/02; H03C1/06; H04B1/62
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
132 words
A method of aligning a single sideband transmission system having a receiver and having a transmitter responsive to a predistortion circuit, comprising: applying as an input to said predistortion circuit selected multiple test tones having the capability of producing intermodulation distortion, applying a radio frequency output of said transmitter to the input of said receiver at power levels at least as high as those experienced in a practical radio transmission environment, filtering selected ones of said test tones present in an intermediate frequency output of said receiver to remove the intermodulation distortion producing capability thereof, monitoring the intermodulation distortion present in the filtered intermediate frequency output of said receiver, and adjusting said predistortion circuit to minimize the monitored intermodulation distortion, whereby the system, including both the transmitter and receiver is appropriately predistorted.
Claim 2
Independent Claim
132 words
A method of aligning a single sideband transmission system having a receiver and having a transmitter responsive to a predistortion circuit, comprising: applying as an input to said predistortion circuit selected multiple test tones having the capability of producing intermodulation distortion, applying a radio frequency output of said transmitter to the input of said receiver at power levels at least as high as those experienced in a practical radio transmission environment, filtering selected ones of said test tones present in an intermediate frequency output of said receiver to remove the intermodulation distortion producing capability thereof, monitoring the intermodulation distortion present in the filtered intermediate frequency output of said receiver, and adjusting said predistortion circuit to minimize the monitored intermodulation distortion, whereby the system, including both the transmitter and receiver is appropriately predistorted.
Claim 3
Dependent Claim
61 words
The method of claim 1, wherein said step of applying an output of the transmitter to the input of the receiver includes transmitting from a first station and receiving at a distant second station, and said monitoring includes transmitting a signal including information of said filtered intermediate frequency output from said second station and receiving said signal at said first station.
References Cited (Backward Citations)
US2924703A
Cited
US3195047A
Cited
US3271679A
Cited
US3434056A
Cited
US3467866A
Cited
DE2638591A1
Cited
US4088948A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-12-23 | 1989-06-24 | 1989-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-12-23 | 1993-06-24 | 1993-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-12-23 | 1997-06-24 | 1997-12-24 | $7700.00 | Window Closed / Lapsed |