RFIC with dynamically controlled power amplifier

• US 7,787,839 B2
• Filed: 04/16/2007
• Issued: 08/31/2010
• Est. Priority Date: 12/06/2006
• Status: Expired due to Fees

• Current Assignee: Avago Technologies General IP PTE Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Liao, Hsin-Hsing
• Primary Examiner(s): Urban; Edward
• Assistant Examiner(s): Hannon; Christian A
• Application Number:
  US11/787,293
• Publication Number:
  US 20080139128A1
• Time in Patent Office: 1,233 Days
• Field of Search: 4551151-1154, 455/117, 455/127.1, 455/126, 455/129
• US Class Current: 455/127.1
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04

Abstract

A radio frequency (RF) front-end includes a power amplifier module and a power amplifier control module. The power amplifier module is coupled to amplify an outbound RF signal in accordance with a control signal to produce an amplified outbound RF signal. The power amplifier control module is coupled to generate the control signal based on at least one of forward power of the amplified outbound RF signal and reflected power of the amplified outbound RF signal.

Claims

1. A radio frequency (RF) front-end comprises:

a power amplifier module coupled to amplify an outbound RF signal in accordance with a control signal to produce an amplified outbound RF signal; and

power amplifier control module coupled to generate the control signal based on at least one of forward power of the amplified outbound RF signal and reflected power of the amplified outbound RF signal, the power amplifier control module including;

a first rectifying circuit coupled to rectify the amplified outbound RF signal to produce a rectified forward outbound RF signal, wherein the rectified forward outbound RF signal is representative of the forward power;

a second rectifying circuit coupled to rectify the amplified outbound RF signal to produce a rectified reflected outbound RF signal, wherein the rectified reflected outbound RF signal is representative of the reflected power;

a first comparison module coupled to compare the rectified reflected outbound RF signal with a reflected power threshold and to output an over power indication when the rectified reflected outbound RF signal compares unfavorably with the reflected power threshold;

a first control circuit to generate the control signal as a bias adjust signal based on an interpretation of the rectified forward outbound RF signal; and

a second control circuit to generate the control signal as a power down signal for the power amplifier module based on the over power indication.

2. The RF front-end of claim 1, wherein the power amplifier control module includes a directional coupler coupled to provide the amplified outbound RF signal to an antenna structure and also coupled to the first and second rectifying circuits.

3. The RF front-end of claim 2, wherein the first control circuit further functions to:

determine a difference between the forward power and the reflected power based on the rectified forward outbound RF signal and rectified reflected outbound RF signal; and

generate the control signal as an impedance adjust signal to adjust output impedance of the power amplifier module.

4. The RF front-end of claim 3, wherein the first control circuit further includes:

a first mathematical module to generate a mathematical representation of the rectified forward outbound RF signal; and

a second comparison module coupled to compare the mathematical representation of the rectified forward outbound RF signal with operational parameters of the power amplifier module;

wherein, the bias adjust signal is based on the comparison of the mathematical representation of the rectified forward outbound RF signal with operational parameters of the power amplifier module.

5. The RF front-end of claim 4, wherein the first control circuit further includes:

a second mathematical module to generate a mathematical representation of the rectified reflected outbound RF signal; and

a third comparison module coupled to compare the mathematical representation of the rectified forward outbound RF signal with the mathematical representation of the rectified reflected outbound RF signal

wherein, the impedance adjust signal is based on the comparison of the mathematical representation of the rectified forward outbound RF signal with the mathematical representation of the rectified reflected outbound RF signal.

6. A radio frequency integrated circuit (RFIC) comprises:

a baseband processing module coupled to;

convert outbound data into an outbound symbol stream in accordance with a wireless communication protocol; and

convert an inbound symbol stream into inbound data in accordance with the wireless communication protocol;

a receiver section coupled to convert an inbound radio frequency (RF) signal into the inbound symbol stream in accordance with a receiver local oscillation;

an up-conversion module coupled to convert the outbound symbol stream into an outbound RF signal in accordance with a transmitter local oscillation;

a power amplifier module coupled to amplify an outbound RF signal in accordance with a control signal to produce an amplified outbound RF signal; and

power amplifier control module coupled to generate the control signal based on at least one of forward power of the amplified outbound RF signal and reflected power of the amplified outbound RF signal, the power amplifier control module including;

a first rectifying circuit coupled to rectify the amplified outbound RF signal to produce a rectified forward outbound RF signal, wherein the rectified forward outbound RF signal is representative of the forward power;

a second rectifying circuit coupled to rectify the amplified outbound RF signal to produce a rectified reflected outbound RF signal, wherein the rectified reflected outbound RF signal is representative of the reflected power;

a first comparison module coupled to compare the rectified reflected outbound RF signal with a reflected power threshold and to output an over power indication when the rectified reflected outbound RF signal compares unfavorably with the reflected power threshold;

a first control circuit to generate the control signal as a bias adjust signal based on an interpretation of the rectified forward outbound RF signal; and

a second control circuit to generate the control signal as a power down signal for the power amplifier module based on the over power indication.

7. The RFIC of claim 6, wherein the power amplifier control module includes a directional coupler coupled to provide the amplified outbound RF signal to an antenna structure and also coupled to the first and second rectifying circuits.

8. The RFIC of claim 7, wherein the first control circuit further functions to:

determine a difference between the forward power and the reflected power based on the rectified forward outbound RF signal and rectified reflected outbound RF signal; and

generate the control signal as an impedance adjust signal to adjust output impedance of the power amplifier module.

9. The RFIC of claim 8, wherein the first control circuit further includes:

a first mathematical module to generate a mathematical representation of the rectified forward outbound RF signal; and

a second comparison module coupled to compare the mathematical representation of the rectified forward outbound RF signal with operational parameters of the power amplifier module

wherein the bias adjust signal is based on the comparison of the mathematical representation of the rectified forward outbound RF signal with operational parameters of the power amplifier module.

10. The RFIC of claim 9, wherein the first control circuit further includes:

a second mathematical module to generate a mathematical representation of the rectified reflected outbound RF signal; and

a third comparison module coupled to compare the mathematical representation of the rectified forward outbound RF signal with the mathematical representation of the rectified reflected outbound RF signal;

wherein, the impedance adjust signal is based on the comparison of the mathematical representation of the rectified forward outbound RF signal with the mathematical representation of the rectified reflected outbound RF signal.