Beamforming RF circuit and applications thereof

• US 8,120,532 B2
• Filed: 03/26/2010
• Issued: 02/21/2012
• Est. Priority Date: 03/10/2006
• Status: Expired due to Fees

• Current Assignee: Avago Technologies International Sales Pte Limited (Broadcom, Inc.)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Rofougaran, Ahmadreza (Reza)
• Primary Examiner(s): Tarcza, Thomas
• Assistant Examiner(s): Mull, Fred H
• Application Number:
  US12/732,312
• Publication Number:
  US 20100171661A1
• Time in Patent Office: 697 Days
• Field of Search: 342369-372
• US Class Current: 342/369
• CPC Class Codes: H01Q 3/26 varying the relative phase or relative amplitude of energisation between two or more active radiating elements; varying the distribution of energy across a radiating aperture H01Q3/12, H01Q3/22, H01Q3/24 take precedence

Abstract

A beamforming radio frequency (RF) circuit includes a plurality of antennas, a plurality of amplifiers and an adjust module. The plurality of antennas is operably coupled to interrelate a plurality of beamformed signal components with a beamformed signal. The plurality of amplifiers is operably coupled to interrelate the plurality of beamformed signal components with a plurality of adjusted signal components. The adjust module is operably coupled to interrelate coordinates of a signal with the plurality of adjusted signal components.

Claims

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

an adjust module configured to adjust coordinates of an outbound RF signal to produce a plurality of RF signal components based on a beamforming factor, wherein the adjust module comprises, for each of the plurality of RF signal components;

a first gain stage to amplify an I component of the outbound RF signal in accordance with a first gain value to produce a gained I component;

a second gain stage to amplify a Q component of the outbound RF signal in accordance with a second gain value to produce a gained Q component; and

an adder operably coupled to add the gained I component and the gained Q component to produce a corresponding one of the plurality of RF signal components, wherein the first and second gain values are based on the beamforming factor; and

a plurality of power amplifiers configured to amplify the plurality of RF signal components output by the adjust module to produce a plurality of amplified RF signal components, wherein one or more of the plurality of power amplifiers have different gain settings based on the beamforming factor, and wherein the plurality of power amplifiers provide the plurality of amplified RF signal components to a plurality of antennas that transmit the plurality of amplified RF signal components.

2. The RFIC of claim 1, further comprising:

baseband processing module configured to convert outbound data into an outbound baseband signal; and

an up-conversion module configured to convert the outbound baseband signal into an outbound RF signal.

3. The RFIC of claim 1, wherein the adjust module further comprises:

a receiver configured to receive feedback from a targeted recipient of the beamformed RF signal; and

processing module configured to generate the beamforming factor based on the feedback, wherein the adjust module adjusts the coordinates of the outbound RF signal in accordance with the beamforming factor.

4. The RFIC of claim 3, wherein the processing module further functions to:

sequentially adjust the coordinates of the outbound RF signal to produce a plurality of sequentially adjusted coordinates of the plurality of RF signal components;

for each of the plurality of sequentially adjusted coordinates of the plurality of RF signal components;

enabling transmission of the beamformed RF signal;

determining whether feedback is received for the beamformed RF signal;

when the feedback is received, saving the feedback with respect to a corresponding one of the plurality of sequentially adjusted coordinates of the plurality of RF signal components to produce saved feedback; and

determining the beamforming factor from the saved feedback.

5. The RFIC of claim 4, wherein the processing module further functions to:

enable transmission of the beamformed RF signal for a given adjustment of the coordinates of the plurality of RF signal components;

determine whether feedback is received for the beamformed RF signal;

when the feedback is received, determine whether the given adjustment of the coordinates of the plurality of RF signal components provides a desired level of transmission of the beamformed RF signal based on the feedback; and

when the given adjustment of the coordinates of the plurality of RF signal components does not provide the desired level of transmission of the beamformed RF signal, further adjusting the coordinates of the plurality of RF signal components until the desired level of transmission of the beamformed RF signal is obtained.

6. The RFIC of claim 1, wherein the adjust module further functions to adjust transmit power of at least one of the plurality of power amplifiers based on the beamforming factor.

7. A radio frequency (RF) transmitter comprises:

an adjust module configured to adjust coordinates of an outbound RF signal to produce a plurality of RF signal components based on a beamforming factor, wherein the adjust module comprises, for each of the plurality of RF signal components;

a first gain stage to amplify an I component of the outbound RF signal in accordance with a first gain value to produce a gained I component;

a second gain stage to amplify a Q component of the outbound RF signal in accordance with a second gain value to produce a gained Q component; and

an adder operably coupled to add the gained I component and the gained Q component to produce a corresponding one of the plurality of RF signal components, wherein the first and second gain values are based on the beamforming factor; and

a plurality of power amplifiers configured to amplify the plurality of RF signal components output by the adjust module to produce a plurality of amplified RF signal components, wherein one or more of the plurality of power amplifiers have different gain settings based on the beamforming factor; and

a plurality of antennas operably coupled to transmit the plurality of amplified RF signal components to produce a beamformed RF signal.

8. The RF transmitter of claim 7, wherein the adjust module further functions to adjust the gain setting of at least one of the plurality of power amplifiers based on the beamforming factor.

9. The RF transmitter of claim 7 further comprises:

the first gain stage amplifying the I component of the outbound RF signal in accordance with a first gain value; and

the second gain stage amplifying the Q component of the outbound RF signal in accordance with a second gain value, wherein the first and second gain values establish a desired coordinate for the corresponding one of the plurality of RF signal components.

10. The RF transmitter of claim 7 further functions to:

receive feedback from a targeted recipient of the beamformed RF signal; and

generate the beamforming factor based on the feedback.

11. The RF transmitter of claim 10 further functions to:

sequentially adjust coordinates of the outbound RF signal to produce a plurality of sequentially adjusted coordinates of the plurality of RF signal components;

for each of the plurality of sequentially adjusted coordinates of the plurality of RF signal components;

enabling transmission of the beamformed RF signal;

determining whether feedback is received for the beamformed RF signal;

when the feedback is received, saving the feedback with respect to a corresponding one of the plurality of sequentially adjusted coordinates of the plurality of RF signal components to produce saved feedback; and

determining the beamforming factor from the saved feedback.

12. The RF transmitter of claim 10 further functions to:

enabling transmission of the beamformed RF signal for a given adjustment of coordinates of the plurality of RF signal components;

determining whether feedback is received for the beamformed RF signal;

when the feedback is received, determining whether the given adjustment of the coordinates of the plurality of RF signal components provides a desired level of transmission of the beamformed RF signal based on the feedback; and

when the given adjustment of the coordinates of the plurality of RF signal components does not provide the desired level of transmission of the beamformed RF signal, further adjusting the coordinates of the plurality of RF signal components until the desired level of transmission of the beamformed RF signal is obtained.

13. The RF transmitter of claim 7, wherein the plurality of antennas comprises:

a first antenna having a first polarization; and

a second antenna having a second polarization.

14. A radio frequency (RF) front end comprises:

a transmitter section including;

an adjust module configured to adjust coordinates of an outbound RF signal to produce a plurality of RF signal components based on a beamforming factor;

a plurality of power amplifiers configured to amplify the plurality of RF signal components output by the adjust module to produce a plurality of amplified RF signal components, wherein one or more of the plurality of power amplifiers have different gain settings based on the beamforming factor; and

a plurality of antennas operably coupled to transmit the plurality of amplified RF signal components to produce a beamformed RF signal;

a receiver section that receives an RF feedback signal from a targeted recipient of the beamformed RF signal, wherein the beamforming factor is generated based on the RF feedback signal; and

wherein the adjust module is further configured to, when the RF feedback signal indicates that a desired level of transmission of the beamformed RF signal is not provided by the plurality of antennas, further adjusting the coordinates of the outbound RF signal components and one or more of the gain settings of the plurality of power amplifiers.

15. The radio frequency (RF) front end of claim 14, wherein the receiver section comprises:

a plurality of low noise amplifiers, wherein the plurality of antennas receive the RF feedback signal and provide therefrom a plurality of beamformed signal components to the plurality of low noise amplifiers;

the plurality of low noise amplifiers operably coupled to amplify the plurality of beamformed signal components to produce a plurality of adjusted signal components; and

the adjust module operably coupled to determine adjusted coordinates of the plurality of adjusted signal components and to recapture the signal based on the adjusted coordinates.

16. The radio frequency (RF) front end of claim 15 further comprises:

an antenna coupling module operably coupled to provide the plurality of amplified RF signal components from the plurality of power amplifiers to the plurality of antennas and to provide the plurality of beamformed signal components from the plurality of antennas to the plurality of low noise amplifiers.