Patent US4935705A successfully refreshed from Google Patents.
US4935705A
Expired / Lapsed
US
⏱️ 0.0 years remaining
High efficiency variable power amplifier
Assignee: Motorola Solutions Inc
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Filing: 1988-12-29
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Granted: 1990-06-19
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Expires: 2008-12-29
Abstract
Abstract A high efficiency variable power amplifier suitable for use in a battery powered device is provided wherein a variable power amplifier has at least a first (2) and a second (12) amplification stage. Base bias potential (8) for the second amplification stage (12) is derived from the bias potential provided to the first amplification stage. In this way, as the bias potential to the first amplification stage is modified to vary the output power, the base bias potential for the second amplification stage is correspondingly modified to maintain the amplifier's efficiency.
Inventors
- 👤 Cris S. Estanislao
- 👤 Ole Hammer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 15:38
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/02; H03F1/0205; H03F1/0261
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
92 words
A radio frequency power amplifier comprising: first amplification means having an input port, an output port, and a port for receiving a variable amplifier bias potential; second amplification means having an output port, a port for receiving a fixed amplifier bias, and an input port coupled to said output port of said first amplification means; and bias means for receiving said variable amplifier bias potential to provide a variable input bias potential to said input port of said second amplification means to bias said second amplification means in a Class C mode.
Claim 2
Dependent Claim
92 words
A radio frequency power amplifier comprising: first amplification means having an input port, an output port, and a port for receiving a variable amplifier bias potential; second amplification means having an output port, a port for receiving a fixed amplifier bias, and an input port coupled to said output port of said first amplification means; and bias means for receiving said variable amplifier bias potential to provide a variable input bias potential to said input port of said second amplification means to bias said second amplification means in a Class C mode.
Claim 3
Dependent Claim
13 words
The amplifier of claim 1 wherein said bias means comprises a voltage divider.
Claim 4
Dependent Claim
14 words
The amplifier of claim 1 wherein said bias means comprises a resistive voltage divider.
Claim 5
Dependent Claim
17 words
The amplifier of claim 1 wherein said bias means comprises a diode clamp and a voltage divider.
Claim 6
Dependent Claim
16 words
The amplifier of claim 1 wherein said first amplification means provides for a variable output signal.
Claim 7
Dependent Claim
16 words
The amplifier of claim 1 wherein said second amplification means provides for a variable output signal.
Claim 8
Dependent Claim
106 words
A radio frequency power amplifier comprising: first amplification means for providing a variable output signal having an input port, an output port, and a port for receiving a variable amplifier bias potential; second amplification means for providing a variable output signal having an output port, a port for receiving a fixed amplifier bias, and an input port coupled to said output port of said first amplification means; and voltage divider bias means for receiving said variable amplifier bias potential to provide a variable input bias potential to said input port of said second amplification means to bias said second amplification means in a Class C mode.
Claim 9
Dependent Claim
106 words
A radio frequency power amplifier comprising: first amplification means for providing a variable output signal having an input port, an output port, and a port for receiving a variable amplifier bias potential; second amplification means for providing a variable output signal having an output port, a port for receiving a fixed amplifier bias, and an input port coupled to said output port of said first amplification means; and voltage divider bias means for receiving said variable amplifier bias potential to provide a variable input bias potential to said input port of said second amplification means to bias said second amplification means in a Class C mode.
Claim 10
Independent Claim
73 words
A method of biasing a radio frequency power amplifier comprising the steps of: a. providing a variable amplifier bias potential to a first amplifier and a fixed amplifier bias potential to a second amplifier; b. decreasing said variable amplifier bias potential to provide a variable input bias potential; and c. biasing an input of the second amplifier with said variable input bias potential to bias said second amplifier in a Class C mode.
Claim 11
Independent Claim
73 words
A method of biasing a radio frequency power amplifier comprising the steps of: a. providing a variable amplifier bias potential to a first amplifier and a fixed amplifier bias potential to a second amplifier; b. decreasing said variable amplifier bias potential to provide a variable input bias potential; and c. biasing an input of the second amplifier with said variable input bias potential to bias said second amplifier in a Class C mode.
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) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |