Multi-band power amplification system having enhanced efficiency through elimination of band selection switch

• US 10,177,711 B2
• Filed: 09/29/2015
• Issued: 01/08/2019
• Est. Priority Date: 02/15/2015
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Skyworks Solutions Incorporated
• Inventors: Lehtola, Philip John
• Primary Examiner(s): Sorowar, Golam
• Application Number:
  US14/869,955
• Publication Number:
  US 20160241207A1
• Time in Patent Office: 1,197 Days
• CPC Class Codes: H03F 1/0205 in transistor amplifiers
• CPC Class Codes: H03F 1/0227 using supply converters
• CPC Class Codes: H03F 1/0288 using a main and one or several auxiliary peaking amplifiers whereby the load is connected to the main amplifier using an impedance inverter, e.g. Doherty amplifiers
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 2200/102 A non-specified detector of a signal envelope being used in an amplifying circuit
• CPC Class Codes: H03F 2200/105 A non-specified detector of the power of a signal being used in an amplifying circuit
• CPC Class Codes: H03F 2200/111 the amplifier being a dual or triple band amplifier, e.g. 900 and 1800 MHz, e.g. switched or not switched, simultaneously or not
• CPC Class Codes: H03F 2200/171 A filter circuit coupled to the output of an amplifier
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2203/21109 An input signal being distributed by switching to a plurality of paralleled power amplifiers
• CPC Class Codes: H03F 2203/21157 A filter circuit being added at the output of a power amplifier stage
• CPC Class Codes: H03F 2203/7209 the gated amplifier being switched from a first band to a second band
• CPC Class Codes: H03F 3/191 Tuned amplifiers H03F3/193, H03F3/195 take precedence
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03F 3/245 with semiconductor devices only
• CPC Class Codes: H03F 3/72 Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal
• CPC Class Codes: H04B 2001/0408 with power amplifiers

Abstract

Multi-band power amplification system having enhanced efficiency through elimination of band selection switch. In some embodiments, a power amplification system can include a plurality of power amplifiers (PAs), with each PA being configured to receive and amplify a radio-frequency (RF) signal in a frequency band. The power amplification system can further include an output filter coupled to each of the PAs by a separate output path such that the power amplification system is substantially free of a band selection switch between the plurality of PAs and their corresponding output filters. Each PA can be further configured to drive approximately a characteristic load impedance of the corresponding output filter by, for example, the PA being operated with a high-voltage (HV) supply.

Claims

1. A power amplification system comprising:

a plurality of power amplifiers, each configured to amplify a signal in a respective frequency band; and

an output filter coupled to each power amplifier by a separate output path, the output filter having a load impedance and the corresponding power amplifier configured to be operated at a high voltage in an average power tracking mode to provide an impedance that is approximately the same as the load impedance of the output filter, such that the power amplification system is substantially free of a band selection switch between the plurality of power amplifiers and their corresponding output filters to result in a reduction in loss by at least 0.3 dB between each power amplifier and the corresponding output filter, each output path free of an impedance transformation circuit to result in a reduction in loss by at least 0.5 dB between the corresponding power amplifier and the output filter.

2. The power amplification system of claim 1 wherein the impedance of each power amplifier has a value greater than approximately 40 Ohms.

3. The power amplification system of claim 2 wherein the impedance of each power amplifier results in a reduced current drain in the power amplifier.

4. The power amplification system of claim 1 further comprising a supply system configured to provide the high voltage to each power amplifier.

5. The power amplification system of claim 4 wherein the supply system includes a boost DC/DC converter configured to generate the high voltage based on a battery voltage Vbatt.

6. The power amplification system of claim 5 wherein each power amplifier includes a heterojunction bipolar transistor implemented as a gallium arsenide device.

7. The power amplification system of claim 1 wherein each output filter is a transmit filter configured to operate in a corresponding transmit frequency band.

8. The power amplification system of claim 1 wherein the plurality of power amplifiers are implemented on a single semiconductor die.

9. The power amplification system of claim 1 wherein the average power tracking mode of each power amplifier results in the power amplification system having a lower loss than another power amplification system having a similar band handling capability but in which power amplifiers are operated in low voltage.

10. The power amplification system of claim 9 wherein the other power amplification system is an envelope tracking power amplification system.

11. A radio-frequency module comprising:

a packaging substrate configured to receive a plurality of components; and

a power amplification system implemented on the packaging substrate and including a plurality of power amplifiers, each configured to amplify a signal in a frequency band, the power amplification system further including an output filter coupled to each power amplifier by a separate output path, the output filter having a load impedance and the corresponding power amplifier configured to be operated at a high voltage in an average power tracking mode to provide an impedance that is approximately the same as the load impedance of the output filter, such that the power amplification system is substantially free of a band selection switch between the plurality of power amplifiers and their corresponding output filters to result in a reduction in loss by at least 0.3 dB between each power amplifier and the corresponding output filter, each output path free of an impedance transformation circuit to result in a reduction in loss by at least 0.5 dB between the corresponding power amplifier and the output filter.

12. The radio-frequency module of claim 11 wherein each output path is substantially free of an impedance transformation circuit between the corresponding power amplifier and output filter.

13. A wireless device comprising:

a transceiver;

a front-end module in communication with the transceiver and including a packaging substrate configured to receive a plurality of components, the front-end module further including a power amplification system implemented on the packaging substrate, the power amplification system including a plurality of power amplifiers, each configured to amplify a signal in a frequency band, the power amplification system further including an output filter coupled to each power amplifier by a separate output path, the output filter having a load impedance and the corresponding power amplifier configured to be operated at a high voltage in an average power tracking mode to provide an impedance that is approximately the same as the load impedance of the output filter, such that the power amplification system is substantially free of a band selection switch between the plurality of power amplifiers and their corresponding output filters to result in a reduction in loss by at least 0.3 dB between each power amplifier and the corresponding output filter, each output path free of an impedance transformation circuit to result in a reduction in loss by at least 0.5 dB between the corresponding power amplifier and the output filter; and

an antenna in communication with the front-end module and configured to transmit the amplified signal.