RF amplification device with power protection during high supply voltage conditions

Patent metadata

Field	Value
Publication number	US-9793860-B2
Application number	US-201414478822-A
Country	US
Kind code	B2
Filing date	Sep 5, 2014
Priority date	Sep 6, 2013
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

Radio frequency (RF) amplification devices are disclosed along with methods of providing power to an RF signal. In one embodiment, an RF amplification device includes an RF amplification circuit and a voltage regulation circuit. The RF amplification circuit includes a plurality of RF amplifier stages coupled in cascade. The voltage regulation circuit is coupled to provide a regulated voltage to a driver RF amplifier stage. The voltage regulation circuit is configured to generate the regulated voltage so that the maximum output power of the RF amplification circuit is provided approximately at a first power level while the supply voltage is above a threshold voltage level. The first power level should be within the physical capabilities of the RF amplification circuit, and thus, the RF amplification circuit is prevented from being damaged once the supply voltage is above the threshold voltage level.

First claim

What is claimed is:

1. A radio frequency (RF) amplification device comprising:
an RF amplification circuit comprising a plurality of RF amplifier stages coupled in cascade such that each of the plurality of RF amplifier stages is operable to provide amplification to an RF signal, the plurality of RF amplifier stages comprising at least a driver RF amplifier stage and a final RF amplifier stage;
a voltage regulation circuit coupled to provide a regulated voltage to the driver RF amplifier stage such that a maximum output power of the RF amplification circuit is set based on the regulated voltage, wherein the voltage regulation circuit is configured to generate the regulated voltage from a supply voltage so that the regulated voltage is driven approximately to a first voltage level while the supply voltage is below a threshold voltage level and so that the regulated voltage is driven below the first voltage level such that the maximum output power of the RF amplification circuit is provided approximately at a first power level while the supply voltage is above the threshold voltage level.

2. The RF amplification device of claim 1 wherein the voltage regulation circuit is configured to generate the regulated voltage by being configured to:
generate a control reference endogenously from the supply voltage;
set the control reference such that the control reference indicates that a target regulated voltage is set approximately at the first voltage level in response to the supply voltage being below the threshold voltage level;
set the control reference such that the control reference indicates that the target regulated voltage is below the first voltage level and maintains the maximum output power of the RF amplification circuit approximately at the first power level in response to the supply voltage being above the threshold voltage level;
drive the regulated voltage to the target regulated voltage indicated by the control reference.

3. The RF amplification device of claim 2 wherein the target regulated voltage indicated by the control reference is set as a function of the supply voltage in response to the supply voltage being above the threshold voltage level.

4. The RF amplification device of claim 3 wherein the function of the supply voltage decreases the target regulated voltage as the supply voltage increases.

5. The RF amplification device of claim 1 wherein the driver RF amplifier stage is an initial RF amplifier stage of the plurality of RF amplifier stages.

6. The RF amplification device of claim 5 wherein:
the initial RF amplifier stage has a first supply terminus coupled to receive the regulated voltage;
the final RF amplifier stage has a second supply terminus coupled to receive the supply voltage.

7. The RF amplification device of claim 5 wherein:
the initial RF amplifier stage has a first supply terminus coupled to receive the regulated voltage; and
the final RF amplifier stage has a second supply terminus coupled to receive the regulated voltage.

8. The RF amplification device of claim 5 wherein the plurality of RF amplifier stages further comprise an intermediate RF amplifier stage coupled in cascade between the initial RF amplifier stage and the final RF amplifier stage.

9. The RF amplification device of claim 8 wherein:
the initial RF amplifier stage has a first supply terminus coupled to receive the regulated voltage;
the intermediate RF amplifier stage has a second supply terminus coupled to receive the supply voltage; and
the final RF amplifier stage has a third supply terminus coupled to receive the supply voltage.

10. The RF amplification device of claim 8 wherein:
the initial RF amplifier stage has a first supply terminus coupled to receive the regulated voltage;
the intermediate RF amplifier stage has a second supply terminus coupled to receive the regulated voltage; and
the final RF amplifier stage has a third supply terminus coupled to receive the supply voltage.

11. The RF amplification device of claim 8 wherein:
the initial RF amplifier stage has a first supply terminus coupled to receive the regulated voltage;
the intermediate RF amplifier stage has a second supply terminus coupled to receive the regulated voltage; and
the final RF amplifier stage has a third supply terminus coupled to receive the regulated voltage.

12. The RF amplification device of claim 1 wherein the voltage regulation circuit is coupled to provide the regulated voltage to the driver RF amplifier stage such that the maximum output power of the RF amplification circuit is set based on the regulated voltage and wherein the voltage regulation circuit is configured to generate the regulated voltage from the supply voltage while the supply voltage is above the threshold voltage level by being configured to decrease the regulated voltage as the supply voltage increases so that the maximum output power is decreased in order to maintain the maximum output power of the RF amplification circuit approximately at the first power level.

13. The RF amplification device of claim 1 wherein the voltage regulation circuit is configured to generate the regulated voltage from the supply voltage so that the regulated voltage is driven below the first voltage level so that the regulated voltage is driven below the first voltage level such that the maximum output power of the RF amplification circuit is provided approximately at the first power level while the supply voltage is above the threshold voltage level by being configured to drive the regulated voltage so that the regulated voltage is inversely proportional to the supply voltage while the supply voltage is above the threshold voltage level.

14. The RF amplification device of claim 1 wherein the voltage regulation circuit further comprises:
a voltage regulator configured to generate the regulated voltage from the supply voltage;
an error correction circuit configured to:
generate a control reference endogenously from the supply voltage;
set the control reference such that the control reference indicates that a target regulated voltage is set approximately at the first voltage level in response to the supply voltage being below the threshold voltage level;
set the control reference such that the control reference indicates that the target regulated voltage is below the first voltage level and maintains the maximum output power of the RF amplification circuit approximately at the first power level in response to the supply voltage being above the threshold voltage level;
operate the voltage regulator such that the voltage regulator drives the regulated voltage to the target regulated voltage indicated by the control reference.

15. The RF amplification device of claim 14 wherein the voltage regulation circuit is configured to generate the control reference as a reference voltage.

16. The RF amplification device of claim 14 wherein the error correction circuit comprises:
a control reference circuit configured to:
generate the control reference endogenously from the supply voltage;
set the control reference such that the control reference indicates that a target regulated voltage is set approximately at the first voltage level in response to the supply voltage being below the threshold voltage level; and
set the control reference such that the control reference indicates that the target regulated voltage is below the first voltage level and that maintains the maximum output power of the RF amplification circuit approximately at the first power level in response to the supply voltage being above the threshold voltage level;

Assignees

• Rf Micro Devices Inc
• Qorvo Us Inc

Inventors

• Ngo David Q
• Thomas Michael B
• Nadimpalli Praveen Varma

Classifications

• H03F3/19

  with semiconductor devices only · CPC title

• H03F2200/408

  the output amplifying stage of an amplifier comprising three power stages · CPC title

• H03F2203/21193

  the supply voltage of a power amplifier being continuously controlled, e.g. by an active potentiometer · CPC title

• H03F3/21

  with semiconductor devices only {(H03F3/245 takes precedence)} · CPC title

• H03F2200/451

  the amplifier being a radio frequency amplifier · CPC title