DOHERTY POWER AMPLIFIER HAVING REDUCED SIZE

• US 20160248384A1
• Filed: 02/13/2016
• Published: 08/25/2016
• Est. Priority Date: 02/15/2015
• Status: Active Grant

• Current Assignee: Skyworks Solutions Incorporated
• Original Assignee: Skyworks Solutions Incorporated
• Inventors: LEHTOLA, Philip John
• Granted Patent: US 9,923,523 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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 (HV) supply signal;

a Doherty power amplifier (PA) configured to receive the HV supply signal and amplify a radio-frequency (RF) signal; and

an output path configured to receive and route the amplified RF signal to a filter, the output path substantially free of an impedance transformation circuit.

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

3. The power amplification system of claim 2 wherein the HV supply signal is selected such that impedances of the Doherty PA and the filter match sufficiently to allow the output path to be substantially free of the impedance transformation circuit.

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

5. The power amplification system of claim 2 wherein the Doherty PA includes a heterojunction bipolar transistor (HBT).

6. The power amplification system of claim 5 wherein the HBT is a gallium arsenide (GaAs) device.

7. The power amplification system of claim 5 wherein the HV supply signal is provided to a collector of the HBT as Vcc.

8. The power amplification system of claim 2 wherein the filter is a transmit (Tx) filter configured to operate in a corresponding Tx frequency band.

9. The power amplification system of claim 8 wherein the Tx filter is part of a duplexer configured to operate in the Tx frequency band and a corresponding receive (Rx) frequency band.

10. The power amplification system of claim 2 further comprising one or more additional Doherty PAs, each configured to receive the HV supply signal and amplify an RF signal.

11. The power amplification system of claim 10 further comprising an output path configured to receive and route the amplified RF signal for each of the one or more additional Doherty PAs to a corresponding filter, the additional output path substantially free of an impedance transformation circuit.

12. The power amplification system of claim 11 wherein each filter has associated with it a corresponding Doherty PA.

13. The power amplification system of claim 12 wherein the power amplification system is substantially free of a band selection switch between the Doherty PAs and the filters.

14. The power amplification system of claim 13 wherein the power amplification system has a lower loss than another power amplifier system having similar band handling capability but in which the PAs are operated in low voltage.

15. A radio-frequency (RF) module comprising:

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

a power amplification system implemented on the packaging substrate, the power amplification system including a supply system configured to provide a high-voltage (HV) supply signal, the power amplification system further including a Doherty power amplifier (PA) configured to receive the HV supply signal and amplify an RF signal, the power amplification system further including an output path configured to receive and route the amplified RF signal to a filter, the output path substantially free of an impedance transformation circuit.

16. The RF module of claim 15 wherein the RF module is a front-end module (FEM).

17. The RF module of claim 15 wherein the power amplification system is substantially free of a band selection switch between the Doherty PA and the filter.

18. The RF module of claim 17 wherein the power amplification system has a lower loss than another power amplifier system having similar band handling capability but in which a Doherty PA is operated in low voltage.

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

20. A wireless device comprising:

a transceiver configured to generate a radio-frequency (RF) signal;

a front-end module (FEM) in communication with the transceiver, the FEM including a packaging substrate configured to receive a plurality of components, the FEM further including a power amplification system implemented on the packaging substrate, the power amplification system including a supply system configured to provide a high-voltage (HV) supply signal, the power amplification system further including a Doherty power amplifier (PA) configured to receive the HV supply signal and amplify a radio-frequency (RF) signal, the power amplification system further including an output path configured to receive and route the amplified RF signal to a filter, the output path substantially free of an impedance transformation circuit; and

an antenna in communication with the FEM, the antenna configured to transmit the amplified RF signal.