High efficiency radio frequency power amplifier circuitry with reduced distortion

• US 9,705,463 B2
• Filed: 11/26/2014
• Issued: 07/11/2017
• Est. Priority Date: 11/26/2013
• Status: Active Grant

• Current Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Original Assignee: Qorvo US, Inc. (Qorvo, Inc.)
• Inventors: Maxim, George, Leipold, Dirk Robert Walter, Scott, Baker
• Primary Examiner(s): NGUYEN, HIEU P
• Application Number:
  US14/554,774
• Publication Number:
  US 20150145604A1
• Time in Patent Office: 958 Days
• Field of Search: 330305, 330310-311, 330302, 330285, 330296-297
• CPC Class Codes: H03F 1/0211 with control of the supply voltage or current
• CPC Class Codes: H03F 1/0272 by using a signal derived from the output signal
• CPC Class Codes: H03F 1/223 with MOSFET's
• CPC Class Codes: H03F 1/32 Modifications of amplifiers to reduce non-linear distortion by negative feedback H03F1/34
• CPC Class Codes: H03F 1/523 for amplifiers using field-effect devices H03F1/526 takes precedence
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 2200/324 An amplitude modulator or demodulator being used in the amplifier circuit
• CPC Class Codes: H03F 2200/387 A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2200/471 the voltage being sensed
• CPC Class Codes: H03F 2201/3236 A generated signal, e.g. a pulse or an inverted synchronous signal, being added to avoid certain conditions, e.g. clipping
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/193 with field-effect devices H03F3/195 takes precedence
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03F 3/45179 using MOSFET transistors as the active amplifying circuit H03F3/45278 takes precedence
• CPC Class Codes: H03F 3/45394 Pl types H03F3/45421, H03F3/45448 take precedence
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602
• CPC Class Codes: H03G 3/3036 in high-frequency amplifiers or in frequency-changers H03G3/3052, H03G3/32, H03G3/34 take precedence
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04
• CPC Class Codes: H04B 1/0475 with means for limiting noise, interference or distortion H04B1/0483 takes precedence
• CPC Class Codes: H04B 2001/0408 : with power amplifiers
• CPC Class Codes: H04B 2001/0416 : having gain or transmission power control
• CPC Class Codes: H04B 2001/0425 : with linearisation using predistortion

Abstract

Radio frequency power amplifier circuitry includes an amplifier element, power supply modulation circuitry, and bias modulation circuitry. The amplifier element is configured to amplify an RF input signal using a modulated power supply signal and a modulated bias signal to produce an RF output signal. The power supply modulation circuitry is coupled to the amplifier element and configured to provide the modulated power supply signal. The bias modulation circuitry is coupled to the amplifier element and the power supply modulation circuitry and configured to receive the modulated power supply signal and provide the modulated bias signal. Notably, the modulated bias signal is a function of the modulated power supply signal such that the modulated bias signal is configured to maintain a small signal gain of the amplifier element and the phase of the RF input signal at a constant value as the modulated power supply signal changes.

Claims

1. Radio frequency (RF) power amplifier (PA) circuitry comprising:

an amplifier element configured to amplify an RF input signal using a modulated power supply signal to produce an RF output signal;

capacitance compensation circuitry coupled to the amplifier element;

capacitance compensation control circuitry having a control output coupled to a control input of the capacitance compensation circuitry; and

power supply modulation circuitry coupled to the amplifier element and the capacitance compensation control circuitry and configured to provide the modulated power supply signal to the amplifier element and the capacitance compensation control circuitry, wherein;

the capacitance compensation control circuitry is configured to receive the modulated power supply signal and provide a control signal to the capacitance compensation circuitry that in response to the control signal presents a compensation capacitance to the amplifier element, and

the compensation capacitance is a function of the modulated power supply signal such that the compensation capacitance is configured to compensate for changes in an internal capacitance of the amplifier element in order to maintain a phase of the RF output signal at a constant value as the modulated power supply signal changes.

2. The RF PA circuitry of claim 1 wherein the compensation capacitance is also a function of the RF input signal received by the amplifier element.

3. The RF PA circuitry of claim 1 wherein the compensation capacitance is linearly related to the modulated power supply signal.

4. The RF PA circuitry of claim 1 wherein the compensation capacitance is non-linearly related to the modulated power supply signal.

5. The RF PA circuitry of claim 1 wherein:

the power supply modulation circuitry is configured to receive the RF input signal; and

the modulated power supply signal is a function of the RF input signal.

6. The RF PA circuitry of claim 5 wherein the modulated power supply signal is an envelope power supply signal.

7. The RF PA circuitry of claim 1 wherein the amplifier element is a bipolar junction transistor (BJT).

8. The RF PA circuitry of claim 7 wherein the compensation capacitance is configured to compensate for changes in one or more of a base-emitter capacitance and a base-collector capacitance of the amplifier element as the modulated power supply signal changes.

9. The RF PA circuitry of claim 1 wherein the amplifier element comprises two transistors coupled in cascode.

10. The RF PA circuitry of claim 9 wherein the two transistors are metal-oxide-semiconductor field-effect transistors (MOSFETs).

11. The RF PA circuitry of claim 10 wherein the compensation capacitance is configured to compensate for changes in one or more of a gate-drain capacitance and a gate-source capacitance of the amplifier element as the modulated power supply signal changes.

12. The RF PA circuitry of claim 1 further comprising an additional amplifier element coupled in series with the amplifier element.

13. The RF PA circuitry of claim 12 wherein the amplifier element is a driver stage amplifier element and the additional amplifier element is an output stage amplifier element.

14. The RF PA circuitry of claim 12 wherein the amplifier element is an output stage amplifier element and the additional amplifier element is a driver stage amplifier element.

15. The RF PA circuitry of claim 1 wherein the capacitance compensation circuitry is coupled to the amplifier element and configured to present a compensation capacitance to the amplifier element, and further wherein the compensation capacitance is a function of the modulated power supply signal such that the compensation capacitance is configured to compensate for changes in an internal capacitance of the amplifier element in order to maintain a phase of the RF output signal at a constant value as the modulated power supply signal changes.

16. The RF PA circuitry of claim 1 wherein:

an operating range of the modulated power supply signal is between 0.1 V and a maximum available supply voltage; and

a phase variation of the RF output signal is less than 5°

over the operating range of the modulated power supply signal.