Doherty power amplifier having reduced size

• US 9,923,523 B2
• Filed: 02/13/2016
• Issued: 03/20/2018
• 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): Choe, Henry
• Application Number:
  US15/043,555
• Publication Number:
  US 20160248384A1
• Time in Patent Office: 766 Days
• Field of Search: 330295, 330124 R, 330297
• CPC Class Codes: H03F 1/0211 with control of the supply voltage or current
• 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 1/22 by use of cascode coupling, i.e. earthed cathode or emitter stage followed by earthed grid or base stage respectively
• CPC Class Codes: H03F 1/565 using inductive elements
• 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 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2203/21142 Output signals of a plurality of power amplifiers are parallel combined to a common output
• 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 3/245 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

Abstract

Doherty power amplifier having reduced size. In some embodiments, a power amplification system can include a supply system configured to provide a high-voltage supply signal, and a Doherty power amplifier configured to receive the high-voltage supply signal and amplify a radio-frequency (RF) signal. The power amplification system can further include an output path configured to receive and route the amplified RF signal to a filter. The output path can be substantially free of an impedance transformation circuit.

Claims

1. A power amplification system comprising:

a supply system configured to provide a high-voltage supply signal;

a Doherty power amplifier including an input splitter configured to receive and split a signal into a carrier amplifier and a peaking amplifier, and a combiner configured to combine amplified signals from the carrier and peaking amplifiers to provide an output signal, the Doherty power amplifier configured to receive the high-voltage supply signal for operation of the carrier and peaking amplifiers; and

an output path configured to couple the combiner to a filter, the Doherty power amplifier having an impedance substantially the same as an impedance of the filter when operated with the high-voltage supply signal.

2. The power amplification system of claim 1 wherein the supply system includes a boost DC/DC converter configured to generate the high-voltage supply signal based on a battery voltage.

3. The power amplification system of claim 1 wherein the impedance of the Doherty power amplifier has a value of approximately 50 Ohms.

4. The power amplification system of claim 1 wherein each of the carrier amplifier and the peaking amplifier includes a heterojunction bipolar transistor.

5. The power amplification system of claim 4 wherein the heterojunction bipolar transistor is implemented as a gallium arsenide device.

6. The power amplification system of claim 4 wherein the high-voltage supply signal is provided to a collector of the heterojunction bipolar transistor.

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

8. The power amplification system of claim 7 wherein the transmit filter is part of a duplexer configured to operate in the transmit frequency band and a corresponding receive frequency band.

9. The power amplification system of claim 1 further comprising one or more additional Doherty power amplifiers, each configured to operate with the high-voltage supply signal.

10. The power amplification system of claim 9 further comprising an output path configured to couple each of the one or more additional Doherty power amplifiers to a filter, each additional Doherty power amplifier having an impedance substantially the same as an impedance of the respective filter when operated with the high-voltage supply signal.

11. The power amplification system of claim 10 wherein the power amplification system is substantially free of a band selection switch between the Doherty power amplifiers and the respective filters.

12. The power amplification system of claim 11 wherein the power amplification system has a lower loss than another power amplifier system having similar band handling capability but in which the Doherty power amplifiers are operated in low voltage.

13. 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 supply system configured to provide a high-voltage supply signal, the power amplification system further including a Doherty power amplifier having an input splitter configured to receive and split a signal into a carrier amplifier and a peaking amplifier, and a combiner configured to combine amplified signals from the carrier and peaking amplifiers to provide an output signal, the Doherty power amplifier configured to receive the high-voltage supply signal for operation of the carrier and peaking amplifiers, the power amplification system further including an output path configured to couple the combiner to a filter, the Doherty power amplifier having an impedance substantially the same as an impedance of the filter when operated with the high-voltage supply signal.

14. The radio-frequency module of claim 13 wherein the radio-frequency module is a front-end module.

15. The radio-frequency module of claim 13 wherein the power amplification system is substantially free of a band selection switch between the Doherty power amplifier and the filter.

16. The radio-frequency module of claim 15 wherein the power amplification system has a lower loss than another power amplifier system having similar band handling capability but in which a Doherty power amplifier is operated in low voltage.

17. The radio-frequency module of claim 15 wherein the radio-frequency module has an area that is significantly less than another radio-frequency module having an amplification system with an impedance transformation circuit and a band selection switch.

18. A wireless device comprising:

a transceiver configured to generate a signal;

a front-end module in communication with the transceiver, and having a power amplification system including a supply system configured to provide a high-voltage supply signal, the power amplification system further including a Doherty power amplifier having an input splitter configured to receive and split the signal into a carrier amplifier and a peaking amplifier, and a combiner configured to combine amplified signals from the carrier and peaking amplifiers to provide an output signal, the Doherty power amplifier configured to receive the high-voltage supply signal for operation of the carrier and peaking amplifiers, the power amplification system further including an output path configured to couple the combiner to a filter, the Doherty power amplifier having an impedance substantially the same as an impedance of the filter when operated with the high-voltage supply signal; and

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