Radio transmitters with temperature compensated power control profiles and methods of operating same

• US 20040235438A1
• Filed: 05/19/2003
• Published: 11/25/2004
• Est. Priority Date: 05/19/2003
• Status: Active Grant

• Current Assignee: Sony Ericsson Mobile Communications AB (Sony Group Corp.)
• Original Assignee: Sony Ericsson Mobile Communications AB (Sony Group Corp.)
• Inventors: Karlsson, Soren, Quilisch, Hakan
• Granted Patent: US 7,068,985 B2
• Time in Patent Office: Days
• US Class Current: 455/127.2
• CPC Class Codes: H03G 3/3047 for intermittent signals, e.g. burst signals
• CPC Class Codes: H03G 3/3084 in receivers or transmitters for electromagnetic waves other than radiowaves, e.g. lightwaves H03G3/32, H03G3/34 take precedence
• CPC Class Codes: H04B 1/036 Cooling arrangements
• CPC Class Codes: H04B 2001/0416 having gain or transmission power control
• CPC Class Codes: H04W 52/362 Aspects of the step size
• CPC Class Codes: H04W 52/52 using AGC [Automatic Gain Control] circuits or amplifiers

Abstract

A radio transmitter includes a power control table, a power amplifier, and a power controller. The power control table includes a plurality of control values. The power amplifier amplifies an RF signal for transmission with an adjustable gain. The power controller adjusts the gain of the power amplifier based on the power control table and a temperature signal that is indicative of a temperature of at least a portion of the radio transmitter.

Claims

1. A radio transmitter comprising:

a power control table that includes a plurality of control values;

a power amplifier that is configured to amplify with an adjustable gain an RF signal for transmission;

a power controller that is configured to adjust the gain of the power amplifier based on the control values of the power control table and a temperature signal that is indicative of a temperature of at least a portion of the radio transmitter.

2. The radio transmitter of claim 1, wherein:

the power amplifier comprises a voltage-controlled power amplifier that has a gain that is adjustable based on a control voltage profile; and

the power controller is further configured to generate the control voltage profile based on the temperature signal.

3. The radio transmitter of claim 2 wherein the power controller is further configured to adjust a timing profile for the control voltage profile based on the temperature signal.

4. The radio transmitter of claim 1 wherein the power control table includes a plurality of control values that define a profile of ramping up and ramping down the gain of the power amplifier according to a time division multiple access communication protocol.

5. The radio transmitter of claim 1, wherein:

the power control table comprises a first power control table and a second power control table; and

the power controller is further configured to select between the first and second power control tables to adjust the gain of the power amplifier based upon the temperature signal.

6. The radio transmitter of claim 1, wherein:

the power control table comprises a baseline power control table that defines a plurality of voltage values and corresponding timing values; and

comprises a high temperature offset control table that defines a plurality of voltage values and corresponding timing values; and

the power controller is further configured to adjust the gain of the power amplifier based on the baseline power control table when the temperature signal satisfies a predetermined baseline temperature value, and is configured to combine the values of the baseline power control table and the values of the high temperature offset control table to adjust the gain of the power amplifier when the temperature signal satisfies a predetermined high temperature value.

7. The radio transmitter of claim 6, wherein:

the power control table further comprises a low temperature offset control table that defines-a plurality of voltage values and corresponding timing values; and

the power controller is further configured to combine the values of the baseline power control table and the values of the low temperature offset control table to adjust the gain of the power amplifier when the temperature signal satisfies a predetermined low temperature value.

8. The radio transmitter of claim 6, wherein:

the power controller is further configured to add the values of the high temperature offset control table to the values of the baseline power control table to adjust the gain of the power amplifier when the temperature signal satisfies the predetermined high temperature value, and is configured to remove the values of the low temperature offset power control table from the values of the baseline power control table to adjust the gain of the power amplifier when the temperature signal satisfies the predetermined low temperature value.

9. The radio transmitter of claim 1 wherein the power control table comprises one or more shift registers.

10. The radio transmitter of claim 1 further comprising a thermistor that generates the temperature signal based on a temperature of at least a portion of the radio transmitter.

20. The radio transmitter of claim 1, wherein the temperature dependent control values are generated by an algorithm that relates predetermined control values and the temperature signal to the temperature dependent control values.

11. A method of controlling a power amplifier in a radio transmitter, the method comprising:

providing a power control table that includes a plurality of control values;

amplifying an RF signal for transmission with an adjustable amplification gain;

adjusting the amplification gain based on the plurality of control values in the power control table and based on a temperature signal that is indicative of a temperature of at least the power amplifier.

12. The method of claim 11 wherein adjusting the amplification gain comprises generating a voltage signal based on the power control table and the temperature signal.

13. The method of claim 12 wherein adjusting the amplification gain comprises adjusting a timing of the voltage signal based on the power control table and the sensed temperature.

14. The method of claim 11 wherein providing a power control table comprises providing a plurality of control values that define a profile of ramp up and ramping down the amplification gain according to a time division multiple access communication protocol.

15. The method of claim 11, wherein:

providing a power control table comprises providing a first power control table and a second power control table; and

adjusting the amplification gain comprises selecting between the first power control table and the second power control table based on the temperature signal.

16. The method of claim 11, wherein:

providing a power control table comprises providing a baseline power control table that defines a plurality of voltage values and corresponding timing values, and providing a high temperature offset control table that defines a plurality of voltage values and corresponding timing values; and

adjusting the amplification gain comprises adjusting the amplification gain based on the baseline power control table when the temperature signal satisfies a predetermined baseline temperature value, and comprises adjusting the amplification gain based on a combination of the values of the baseline power control table and the values of the high temperature offset control table when the temperature signal satisfies a predetermined high temperature value.

17. The method of claim 16, wherein:

providing a power control table further comprises providing a low temperature offset control table that defines a plurality of voltage values and corresponding timing values; and

adjusting the amplification gain comprises adjusting the amplification gain based on a combination of the values of the baseline power control table and the values of the low temperature offset control table when the temperature signal satisfies a predetermined low temperature value.

18. The method of claim 16, wherein adjusting the amplification gain comprises:

adding the values of the high temperature offset control table to the values of the baseline power control table to adjust the amplification gain when the temperature signal temperature signal satisfies the predetermined high temperature value; and

removing the values of the low temperature offset control table from the values of the baseline power control table to adjust the amplification gain when the temperature signal satisfies the predetermined low temperature value.

19. A radio transmitter comprising:

a power amplifier that is configured to amplify with an adjustable gain an RF signal for transmission;

a power controller that is configured to adjust the gain of the power amplifier based on temperature dependent control values and a temperature signal that is indicative of a temperature of at least a portion of the radio transmitter.