US6112062A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Predistortion for high power amplifiers
Assignee: Frontgrade Technologies Inc
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Filing: 1997-09-26
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Granted: 2000-08-29
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Expires: 2017-09-26
Abstract
Abstract A predistorter for linear amplification of a complex modulated signal has an input stage, an envelope detector having at least one fast diode and a capacitor at an output for measuring an amplitude of an RF signal, first and second differentiators for taking first and second derivatives with respect to time; and a predistorter controller for adjusting an attenuator and phase shifter based upon the derivatives.
Inventors
- 👤 Ravinder Hans
- 👤 Bernard J. Arntz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 11:09
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/32; H03F1/3241
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
124 words
A predistorter for linear amplification of a complex modulated signal comprising; an input stage; an envelope detector for measuring amplitude of an RF signal; a double differentiator, said double differentiator taking first and second derivatives of said amplitude with respect to time; a summing circuit, said summing circuit adding said derivatives in predetermined ratios; and a controller, said controller receiving said derivatives in predetermined ratios and having a look-up table of stored values of attenuation and phase correction, wherein said predistorter controller further comprises an analog to digital converter, a gain table, a phase table, and at least one digital to analog converter, and said analog to digital converter converts a signal detected from said first and second differentiators in less than 25 nanoseconds.
Claim 2
Dependent Claim
124 words
A predistorter for linear amplification of a complex modulated signal comprising; an input stage; an envelope detector for measuring amplitude of an RF signal; a double differentiator, said double differentiator taking first and second derivatives of said amplitude with respect to time; a summing circuit, said summing circuit adding said derivatives in predetermined ratios; and a controller, said controller receiving said derivatives in predetermined ratios and having a look-up table of stored values of attenuation and phase correction, wherein said predistorter controller further comprises an analog to digital converter, a gain table, a phase table, and at least one digital to analog converter, and said analog to digital converter converts a signal detected from said first and second differentiators in less than 25 nanoseconds.
Claim 3
Dependent Claim
27 words
A predistorter as recited in claim 1, wherein said at least one digital to analog converter has an output which is fed into a dynamically variable attenuator.
Claim 4
Dependent Claim
28 words
A predistorter as recited in claim 1, wherein said at least one digital to analog converter has an output which is fed into a dynamically variable phase shifter.
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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) | 2003-08-29 | 2004-02-28 | 2004-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-08-29 | 2008-02-28 | 2008-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-08-29 | 2012-02-28 | 2012-08-29 | $7700.00 | Window Closed / Lapsed |