Patent US5455968A successfully refreshed from Google Patents.
← Back to Patent Explorer
US5455968A Expired / Lapsed US ⏱️ 0.0 years remaining

Variable power amplifier

Assignee: Motorola Solutions Inc
•
Filing: 1993-10-04
•
Granted: 1995-10-03
•
Expires: 2013-10-04
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract A variable power amplifier (100) includes a final stage amplification device (74) which is biased by a bias network (50) which provides for improved stability over a wide operating range and into high output mismatch conditions of greater than 5:1 VSWR.

Inventors

  • 👤 Chot Pham

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 15:17
CPC Classifications
H; H03; H03F; H03F1/00; H03F1/08; H03F1/083; H03F1/34

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 101 words
A variable power amplifier for providing a variable level output signal, comprising: a first amplifier stage: a variable bias circuit coupled to the first amplifier stage for controlling the gain of the first amplifier stage: a final amplifier stage operatively coupled to the first amplifier stage, the final amplifier stage providing the variable level output signal; and a bias network coupled to the variable bias circuit for providing a bias voltage to the final amplifier stage for causing an idle current of the final amplifier stage to be inversely related to the variable level output signal of the variable power amplifier.
Claim 2
Dependent Claim 101 words
A variable power amplifier for providing a variable level output signal, comprising: a first amplifier stage: a variable bias circuit coupled to the first amplifier stage for controlling the gain of the first amplifier stage: a final amplifier stage operatively coupled to the first amplifier stage, the final amplifier stage providing the variable level output signal; and a bias network coupled to the variable bias circuit for providing a bias voltage to the final amplifier stage for causing an idle current of the final amplifier stage to be inversely related to the variable level output signal of the variable power amplifier.
Claim 3
Dependent Claim 39 words
A variable level power amplifier as defined in claim 1, wherein the final amplifier stage comprises a MOSFET having drain source and gate terminals and the bias network supplies the bias voltage to the gate terminal of the MOSFET.
Claim 4
Dependent Claim 39 words
A variable power amplifier as defined in claim 2, wherein the variable biasing circuit has an input terminal for receiving a control signal and provides an input voltage level to the bias network in response to the control signal.
Claim 5
Dependent Claim 19 words
A variable level power amplifier as defined in claim 2, wherein the MOSFET is an N-channel enhancement mode device.
Claim 6
Dependent Claim 51 words
A variable level power amplifier as defined in claim 3, wherein the control signal received by the variable biasing circuit is a variable voltage level and the input voltage level that the variable biasing circuit provides to the bias network is inversely related to the voltage level of the control signal.
Claim 7
Dependent Claim 140 words
A radio, comprising: a receiver; and a transmitter coupled to the receiver, the transmitter including: a variable power amplifier for providing a variable level output signal, comprising: a first amplifier stage: a variable bias circuit coupled to the first amplifier stage for controlling the gain of the first amplifier stage: a final amplifier stage comprising a MOSFET having drain, source and gate terminals, the final amplifier stage being operatively coupled to the first amplifier stage and providing the variable level output signal; and a bias network coupled to the variable bias circuit providing a bias voltage to the MOSFET's gate terminal, the bias network causing the bias voltage provided to the MOSFET's gate terminal and an idle drain current of the MOSFET to be inversely related to the variable level of the output signal provided by the variable power amplifier.
Claim 8
Dependent Claim 140 words
A radio, comprising: a receiver; and a transmitter coupled to the receiver, the transmitter including: a variable power amplifier for providing a variable level output signal, comprising: a first amplifier stage: a variable bias circuit coupled to the first amplifier stage for controlling the gain of the first amplifier stage: a final amplifier stage comprising a MOSFET having drain, source and gate terminals, the final amplifier stage being operatively coupled to the first amplifier stage and providing the variable level output signal; and a bias network coupled to the variable bias circuit providing a bias voltage to the MOSFET's gate terminal, the bias network causing the bias voltage provided to the MOSFET's gate terminal and an idle drain current of the MOSFET to be inversely related to the variable level of the output signal provided by the variable power amplifier.
Claim 9
Dependent Claim 38 words
A radio as defined in claim 6, further wherein the variable biasing circuit has an input terminal for receiving a control signal and provides an input voltage level to the bias network in response to the control signal.
Claim 10
Dependent Claim 16 words
A radio as defined in claim 7, wherein the MOSFET is an N-channel enhancement mode device.
Claim 11
Dependent Claim 48 words
A radio as defined in claim 7, wherein the control signal received by the variable biasing circuit is a variable voltage level and the input voltage level that the variable biasing circuit provides to the bias network is inversely related to the voltage level of the control signal.

References Cited (Backward Citations)

US4462004A Cited
US4553105A Cited
US5029298A Cited
US5023569A Cited
US5278517A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1998-10-02 1999-04-03 1999-10-03 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2002-10-02 2003-04-03 2003-10-03 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2006-10-02 2007-04-03 2007-10-03 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag