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US6181208B1 Expired / Lapsed US ⏱️ 0.0 years remaining

Switchable path power amplifier with schotky diode combining network

Assignee: Maxim Integrated Products Inc
•
Filing: 1998-03-26
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Granted: 2001-01-30
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Expires: 2018-03-26
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Abstract

Abstract The present invention teaches a power amplifier having two output power devices and a mechanism for switching the output path between these two power devices. The first output power device is designed for power efficient signal amplification at the power amplifier's highest output power level. The second output power device is designed for power efficient signal amplification at the output power level that the power amplifier is most likely to operate. By switching between the two power devices according to the output power level, a high level of power efficiency can be achieved across a broad range of operating states of the power amplifier.

Inventors

  • 👤 Joel R. King
  • 👤 Gordon A. Olsen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-07 18:18
CPC Classifications
H; H03; H03G; H03G1/00; H03G1/0005; H03G1/0088; H03F; H03F3/00; H03F3/72

Claims Analysis

Total Claims: 44
Claim 1
Independent Claim 568 words
A switchable path power amplifier suitable for amplifying an input signal received at a power amplifier input in order to generate an output signal at a power amplifier output the switchable path power amplifier comprising: a first power device including a first power device input coupled to the power amplifier input and a first power device output, the first power device suitable for amplifying the input signal the first power device intended for use during a first operating state of the switchable path power amplifier; a second power device including a second power device input coupled to the power amplifier input and a second power device output, the second power device suitable for amplifying the input signal, the second power device intended for use during a second operating state of the switchable path power amplifier; a combining network device including a first combining network device input coupled to the first power device output, a second combining network device input coupled to the second power device output, and a combining network device output coupled to the power amplifier output, the combining network device being operable to select between the first power device and the second power device such that only one of the first power device and the second power device drives the power amplifier output; and a state determination circuitry operable to determine the operating state of the switchable path power amplifier, wherein the state determination circuitry is arranged to control which power device drives the power amplifier output based upon the state of the switchable path power amplifier, and wherein the state determination circuitry enables the first power device and disables the second power device when the switchable path power amplifier is operating in the first state, and wherein the state determination circuitry enables the second power device and disables the first power device when the switchable path power amplifier is operating in the second state, and wherein the combining network device selects the enabled power device as the power device that drives the power amplifier output, and wherein the combining network device includes: an inductor L 1 having first and second terminals, the first inductor L 1 terminal electrically coupled to the first power device output; a capacitor C 1 having first and second terminals; an inductor L 2 having first and second terminals, the first inductor L 2 terminal being coupled to a common ground reference, and the second inductor L 2 terminal, the second inductor L 1 terminal, and the first capacitor C 1 terminal being coupled together; a transmission line having first and second terminals, the first transmission line terminal, the second capacitor Cl terminal, and the power amplifier output being coupled together; a capacitor C 2 having first and second terminals, the second capacitor terminal C 2 being coupled to the common ground reference; a capacitor C 3 having first and second terminals, the first capacitor C 3 terminal, the first capacitor C 2 terminal, and the second transmission line terminal being coupled together; an inductor L 3 having first and second terminals, the first inductor L 3 terminal being coupled to the common ground reference; and an inductor L 4 having first and second terminals, the first inductor L 4 terminal being coupled to the second power device output, the second inductor L 4 terminal, the second inductor L 3 terminal, and the second capacitor C 2 terminal being coupled together.
Claim 2
Dependent Claim 568 words
A switchable path power amplifier suitable for amplifying an input signal received at a power amplifier input in order to generate an output signal at a power amplifier output the switchable path power amplifier comprising: a first power device including a first power device input coupled to the power amplifier input and a first power device output, the first power device suitable for amplifying the input signal the first power device intended for use during a first operating state of the switchable path power amplifier; a second power device including a second power device input coupled to the power amplifier input and a second power device output, the second power device suitable for amplifying the input signal, the second power device intended for use during a second operating state of the switchable path power amplifier; a combining network device including a first combining network device input coupled to the first power device output, a second combining network device input coupled to the second power device output, and a combining network device output coupled to the power amplifier output, the combining network device being operable to select between the first power device and the second power device such that only one of the first power device and the second power device drives the power amplifier output; and a state determination circuitry operable to determine the operating state of the switchable path power amplifier, wherein the state determination circuitry is arranged to control which power device drives the power amplifier output based upon the state of the switchable path power amplifier, and wherein the state determination circuitry enables the first power device and disables the second power device when the switchable path power amplifier is operating in the first state, and wherein the state determination circuitry enables the second power device and disables the first power device when the switchable path power amplifier is operating in the second state, and wherein the combining network device selects the enabled power device as the power device that drives the power amplifier output, and wherein the combining network device includes: an inductor L 1 having first and second terminals, the first inductor L 1 terminal electrically coupled to the first power device output; a capacitor C 1 having first and second terminals; an inductor L 2 having first and second terminals, the first inductor L 2 terminal being coupled to a common ground reference, and the second inductor L 2 terminal, the second inductor L 1 terminal, and the first capacitor C 1 terminal being coupled together; a transmission line having first and second terminals, the first transmission line terminal, the second capacitor Cl terminal, and the power amplifier output being coupled together; a capacitor C 2 having first and second terminals, the second capacitor terminal C 2 being coupled to the common ground reference; a capacitor C 3 having first and second terminals, the first capacitor C 3 terminal, the first capacitor C 2 terminal, and the second transmission line terminal being coupled together; an inductor L 3 having first and second terminals, the first inductor L 3 terminal being coupled to the common ground reference; and an inductor L 4 having first and second terminals, the first inductor L 4 terminal being coupled to the second power device output, the second inductor L 4 terminal, the second inductor L 3 terminal, and the second capacitor C 2 terminal being coupled together.
Claim 3
Dependent Claim 33 words
A switchable path power amplifier as recited in claim 1 wherein the switchable path power amplifier further comprises state determination circuitry operable to determine the operating state of the switchable path power amplifier.
Claim 4
Dependent Claim 37 words
A switchable path power amplifier as recited in claim 2 wherein the state determination circuitry is arranged to control which power device drives the power amplifier output based upon the state of the switchable path power amplifier.
Claim 5
Dependent Claim 38 words
A switchable path power amplifier as recited in claim 3 wherein the state determination circuitry enables the first power device and disables the second power device when the switchable path power amplifier is operating in the first state.
Claim 6
Dependent Claim 38 words
A switchable path power amplifier as recited in claim 4 wherein the state determination circuitry enables the second power device and disables the first power device when the switchable path power amplifier is operating in the second state.
Claim 7
Dependent Claim 30 words
A switchable path power amplifier as recited in claim 5 wherein the combining network device selects the enabled power device as the power device that drives the power amplifier output.
Claim 8
Dependent Claim 58 words
A switchable path power amplifier as recited in claim 2 wherein the first operating state of the switchable path power amplifier corresponds to the switchable path power amplifier operating at a high power level, and the second operating state of the switchable path power amplifier corresponds to the switchable path power amplifier operating at a low power level.
Claim 9
Dependent Claim 19 words
A switchable path power amplifier as recited in claim 7 wherein the state determination circuitry includes a digital processor.
Claim 10
Dependent Claim 24 words
A switchable path power amplifier as recited in claim 8 wherein the switchable path power amplifier is for use within a cellular transmission system.
Claim 11
Dependent Claim 42 words
A switchable path power amplifier as recited in claim 9 wherein the cellular transmission system adheres to a code division multiple access (CDMA) system and the state of the switchable path power amplifier is defined in part by the CDMA system state.
Claim 12
Dependent Claim 22 words
A switchable path power amplifier as recited in claim 7 wherein the state determination circuitry includes circuitry for sensing an output power.
Claim 13
Dependent Claim 44 words
A switchable path power amplifier as recited in claim 7 wherein the first power device is designed specifically for power efficient operation at the high power level, and the second power device is designed specifically, for power efficient operation at the low power level.
Claim 14
Dependent Claim 48 words
A switchable path power amplifier as recited in claim 12 wherein the first power device includes a first transistor having an output that is the first power device output, and the second power device includes a second transistor having an output that is the second power device output.
Claim 15
Dependent Claim 20 words
A switchable path power amplifier as recited in claim 13 wherein the first and second transistors are field effect transistors.
Claim 16
Dependent Claim 19 words
A switchable path power amplifier as recited in claim 13 wherein the first and second transistors are npn transistors.
Claim 17
Dependent Claim 24 words
A switchable path power amplifier as recited in claim 1 wherein the first and second power devices are formed within a single integrated circuit.
Claim 18
Dependent Claim 27 words
A switchable path power amplifier as recited in claim 16 wherein the combining network device and the single integrated circuit are combined within one integrated circuit package.
Claim 19
Dependent Claim 37 words
A switchable path power amplifier as recited in claim 1 wherein the switchable path power amplifier has a plurality of power devices intended for use during a plurality of operating states of the switchable path power amplifier.
Claim 20
Dependent Claim 68 words
A switchable path power amplifier as recited in claim 1 wherein the inductor L 1 is about 1 nano-Henry, the inductor L 2 is about 22 nano-Henry, the inductor L 3 is about 22 nano-Henry, the inductor L 4 is about 1 nano-Henry, the capacitor C 1 is about 1.6 pico-Farad, the capacitor C 2 is about 4.2 pico-Farad, and the capacitor C 3 is about 11 pico-Farad.
Claim 21
Dependent Claim 65 words
A switchable path power amplifier as recited in claim 1 wherein the combining network device further includes a diode serving as the electrical coupling between the first inductor L 1 terminal and the first power device output, the anode of the schottky diode coupled to the first inductor L 1 terminal and the cathode of the schottky diode coupled to the first power device output.
Claim 22
Dependent Claim 17 words
A switchable path power amplifier as recited in claim 15 wherein the diode is a schottky diode.
Claim 23
Dependent Claim 22 words
A switchable path power amplifier as recited in claim 21 wherein the schottky diode has about 1200 micro meters of junction area.
Claim 24
Dependent Claim 20 words
A switchable path power amplifier as recited in claim 1 wherein the first power device is a linear power device.
Claim 25
Dependent Claim 20 words
A switchable path power amplifier as recited in claim 1 wherein the first power device is a nonlinear power device.
Claim 26
Dependent Claim 442 words
A switchable path power amplifier suitable for use in an RF communications system having a first output power level that corresponds to the highest output power required of the RF communications system and a second output power level that corresponds to the output power at which the RF communications system typically operates, the switchable path power amplifier comprising: a first power device substantially optimized for power efficient signal amplification at the first output power level; a second power device substantially optimized for power efficient signal amplification at the second output power level; a state determination circuitry arranged to determine the power level at which the switchable path power amplifier is operating, the state determination circuitry further operable to a) enable the first power device and disable the second power device when the switchable path power amplifier is operating at the first output power level and b) enable the second power device and disable the first power device when the switchable path power amplifier is operating at the second output power level; and a combining network arranged to decouple a disabled power device from an output load coupled to the switchable path power amplifier such that any effect of the disabled power device upon an amplified electrical signal generated by an enabled power device is negligible, wherein the combining network includes: an inductor L 1 having first and second terminals, the first inductor L 1 terminal electrically coupled to the first power device; a capacitor C 1 having first and second terminals; an inductor L 2 having first and second terminals, the first inductor L 2 terminal being coupled to a common ground reference, and the second inductor L 2 terminal, the second inductor L 1 terminal, and the first capacitor C 1 terminal being coupled together; a transmission line having first and second terminals, the first transmission line terminal, the second capacitor C 1 terminal, and the power amplifier output being coupled together; a capacitor C 2 having first and second terminals, the second capacitor terminal C 2 being coupled to the common ground reference; a capacitor C 3 having first and second terminals, the first capacitor C 3 terminal, the first capacitor C 2 terminal, and the second transmission line terminal being coupled together; an inductor L 3 having first and second terminals, the first inductor L 3 terminal being coupled to the common ground reference; and an inductor L 4 having first and second terminals, the first inductor L 4 terminal being coupled to the second power device, the second inductor L 4 terminal, the second inductor L 3 terminal, and the second capacitor C 2 terminal being coupled together.
Claim 27
Dependent Claim 442 words
A switchable path power amplifier suitable for use in an RF communications system having a first output power level that corresponds to the highest output power required of the RF communications system and a second output power level that corresponds to the output power at which the RF communications system typically operates, the switchable path power amplifier comprising: a first power device substantially optimized for power efficient signal amplification at the first output power level; a second power device substantially optimized for power efficient signal amplification at the second output power level; a state determination circuitry arranged to determine the power level at which the switchable path power amplifier is operating, the state determination circuitry further operable to a) enable the first power device and disable the second power device when the switchable path power amplifier is operating at the first output power level and b) enable the second power device and disable the first power device when the switchable path power amplifier is operating at the second output power level; and a combining network arranged to decouple a disabled power device from an output load coupled to the switchable path power amplifier such that any effect of the disabled power device upon an amplified electrical signal generated by an enabled power device is negligible, wherein the combining network includes: an inductor L 1 having first and second terminals, the first inductor L 1 terminal electrically coupled to the first power device; a capacitor C 1 having first and second terminals; an inductor L 2 having first and second terminals, the first inductor L 2 terminal being coupled to a common ground reference, and the second inductor L 2 terminal, the second inductor L 1 terminal, and the first capacitor C 1 terminal being coupled together; a transmission line having first and second terminals, the first transmission line terminal, the second capacitor C 1 terminal, and the power amplifier output being coupled together; a capacitor C 2 having first and second terminals, the second capacitor terminal C 2 being coupled to the common ground reference; a capacitor C 3 having first and second terminals, the first capacitor C 3 terminal, the first capacitor C 2 terminal, and the second transmission line terminal being coupled together; an inductor L 3 having first and second terminals, the first inductor L 3 terminal being coupled to the common ground reference; and an inductor L 4 having first and second terminals, the first inductor L 4 terminal being coupled to the second power device, the second inductor L 4 terminal, the second inductor L 3 terminal, and the second capacitor C 2 terminal being coupled together.
Claim 28
Dependent Claim 48 words
A switchable path power amplifier as recited in claim 25 wherein the first power device includes a first transistor having a collector that is a first power device output, and the second power device includes a second transistor having a collector that is a second power device output.
Claim 29
Dependent Claim 19 words
A switchable path power amplifier as recited in claim 26 wherein the first and second transistors are npn transistors.
Claim 30
Dependent Claim 20 words
A switchable path power amplifier as recited in claim 26 wherein the first and second transistors are field effect transistors.
Claim 31
Dependent Claim 22 words
A switchable path power amplifier as recited in claim 25 wherein the state determination circuitry includes circuitry for sensing an output power.
Claim 32
Dependent Claim 19 words
A switchable path power amplifier as recited in claim 25 wherein the state determination circuitry includes a digital processor.
Claim 33
Dependent Claim 24 words
A switchable path power amplifier as recited in claim 30 wherein the switchable path power amplifier is for use within a cellular transmission system.
Claim 34
Dependent Claim 43 words
A switchable path power amplifier as recited in claim 31 wherein the cellular transmission system adheres to a code division multiple access (CDMA) system and the power level of the switchable path power amplifier is defined in part by the CDMA system state.
Claim 35
Dependent Claim 24 words
A switchable path power amplifier as recited in claim 25 wherein the first and second power devices are formed within a single integrated circuit.
Claim 36
Dependent Claim 27 words
A switchable path power amplifier as recited in claim 33 wherein the combining network device and the single integrated circuit are combined within one integrated circuit package.
Claim 37
Dependent Claim 38 words
A switchable path power amplifier as recited in claim 25 wherein the switchable path power amplifier has a plurality of power devices intended for use during a plurality of operating power levels of the switchable path power amplifier.
Claim 38
Dependent Claim 64 words
A switchable path power amplifier as recited in claim 25 , wherein the combining network device further includes a diode serving as the electrical coupling between the first inductor L 1 terminal and the first power device, the anode of the schottky diode coupled to the first inductor L 1 terminal and the cathode of the schottky diode coupled to the first power device.
Claim 39
Dependent Claim 17 words
A switchable path power amplifier as recited in claim 36 wherein the diode is a schottky diode.
Claim 40
Dependent Claim 20 words
A switchable path power amplifier as recited in claim 25 wherein the first power device is a linear power device.
Claim 41
Dependent Claim 20 words
A switchable path power amplifier as recited in claim 38 wherein the second power device is a linear power device.
Claim 42
Dependent Claim 20 words
A switchable path power amplifier as recited in claim 28 wherein the second power device is a nonlinear power device.
Claim 43
Dependent Claim 226 words
A switchable path power amplifier suitable for amplifying an input signal received at a power amplifier input in order to generate an output signal at a power amplifier output, the switchable path power amplifier comprising: a first power device including a first power device input coupled to the power amplifier input and a first power device output, the first power device suitable for amplifying the input signal, the first power device intended for use during a first operating state of the switchable path power amplifier; a second power device including a second power device input coupled to the power amplifier input and a second power device output, the second power device suitable for amplifying the input signal, the second power device intended for use during a second operating state of the switchable path power amplifier; and a combining network device including a first combining network device input coupled to the first power device output, a second combining network device input coupled to the second power device output, and a combining network device output coupled to the power amplifier output, the combining network device utilizing schotky diode circuitry to automatically select an active power device from between the first power device and the second power device such that only the active one of the first power device and the second power device drives the power amplifier output.
Claim 44
Dependent Claim 226 words
A switchable path power amplifier suitable for amplifying an input signal received at a power amplifier input in order to generate an output signal at a power amplifier output, the switchable path power amplifier comprising: a first power device including a first power device input coupled to the power amplifier input and a first power device output, the first power device suitable for amplifying the input signal, the first power device intended for use during a first operating state of the switchable path power amplifier; a second power device including a second power device input coupled to the power amplifier input and a second power device output, the second power device suitable for amplifying the input signal, the second power device intended for use during a second operating state of the switchable path power amplifier; and a combining network device including a first combining network device input coupled to the first power device output, a second combining network device input coupled to the second power device output, and a combining network device output coupled to the power amplifier output, the combining network device utilizing schotky diode circuitry to automatically select an active power device from between the first power device and the second power device such that only the active one of the first power device and the second power device drives the power amplifier output.

References Cited (Backward Citations)

US3449685A Cited
US5175871A Cited
US5287543A Cited
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US5530923A Cited
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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) 2004-01-30 2004-07-31 2005-01-30 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2008-01-30 2008-07-31 2009-01-30 $3760.00 Window Closed / Lapsed
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