DYNAMIC RANGE IMPROVEMENTS OF LOAD MODULATED AMPLIFIERS

• US 20110148518A1
• Filed: 11/01/2006
• Published: 06/23/2011
• Est. Priority Date: 11/01/2006
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Rexberg, Leonard, Lejon, Thomas
• Granted Patent: US 8,022,759 B2
• Time in Patent Office: Days
• US Class Current: 330/124.R
• CPC Class Codes: H03F 1/0205 in transistor amplifiers
• CPC Class Codes: H03F 1/0266 by using a signal derived from the input signal
• CPC Class Codes: H03F 1/0294 using vector summing of two or more constant amplitude phase-modulated signals
• CPC Class Codes: H03F 1/3294 Acting on the real and imaginary components of the input signal
• CPC Class Codes: H03F 2200/102 A non-specified detector of a signal envelope being used in an amplifying circuit
• CPC Class Codes: H03F 2200/252 Multiple switches coupled in the input circuit of an amplifier are controlled by a circuit, e.g. feedback circuitry being controlling the switch
• CPC Class Codes: H03F 2200/336 A I/Q, i.e. phase quadrature, modulator or demodulator being used in an amplifying circuit
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/24 of transmitter output stages
• CPC Class Codes: H03G 3/3042 in modulators, frequency-changers, transmitters or power amplifiers transmission power control in bidirectional transmission systems H04W52/04

Abstract

The present invention relates to methods and devices to control and operate the functionality of a power amplifier system (100) capable of operating in at least three differential amplification modes. The drive signal'"'"'s amplitude envelope controls an integrated switch network (104; 105, 106) that routes both the signal envelope and signal phase to different modulation blocks (111, 112: 109, 110: 115). Depending on the envelope strength, the operational mode of the amplifier system is possible to alter to best serve the signal statistics to provide the highest overall power efficiency.

Claims

1. A method for power amplifying an input drive signal to a power amplification system comprising at least three different power amplification modes, wherein each amplification mode is dedicated to operate within a pre-determined amplification interval, said method comprising the step of determining the momentary envelope value (E) of the input drive signal (S_in) (step 1), and the step of:

switching amplification mode to one of the at least three amplification modes depending on the determined momentary envelope value (E).

2. The method according to claim 1, wherein the switching step comprises the steps of:

operating the power amplification system in a first amplification mode if the momentary envelope value (E) is determined to be within a first amplification interval (steps 2 and 3);

operating the power amplification system in a second amplification mode if the momentary envelope value (E) is determined to be within a second amplification interval (steps 4 and 5);

operating the power amplification system in a third amplification mode if the momentary envelope value (E) is determined to be within a third amplification interval (steps 4 and 6).

3. The method according to claim 2, wherein when the system is operated in the first amplification mode, an outphasing technique is used for power amplifying the input drive signal.

4. The method according to claim 3, wherein when the system is operated in the second amplification mode, a Dynamic Load modulation technique is used for power amplifying the input drive signal.

5. The method according to claim 3, wherein when the system is operated in the second amplification mode, an Envelope Elimination and Restoration (EER) technique is used for power amplifying the input drive signal.

6. The method according to claim 4, wherein when the system is operated in the third amplification mode, an Envelope Elimination and Restoration (EER) technique is used for power amplifying the input drive signal.

7. The method according to claim 5, wherein when the system is operated in the third amplification mode, a Dynamic Load technique is used for power amplifying the input drive signal.

8. The method according to any of the preceding claims, wherein the power amplification system comprises a pair of amplifiers.

9. The method according to claim 8, wherein the amplifiers may be any of amplifier class B, C, D, E, E/F, F.

17. The system according to any of the preceding claims, wherein the power amplification system comprises a pair of amplifiers.

18. The system according to claim 17, wherein the amplifiers may be any of amplifier class B, C, D, E. E/F, F

27. The switching amplification mode device according to any of the preceding claims, wherein the power amplification system comprises a pair of amplifiers.

28. The switching amplification mode device according to claim 27, wherein the amplifiers may be any of amplifier class B, C, D, E, E/F, F.

10. A power amplifying system (100) for power amplifying an input drive signal (S_in) to the system, which system is arranged to operate in at least three different power amplification modes, wherein each amplification mode is dedicated to operate within a pre-determined amplification interval, and which system comprises:

determining device (102, 103) for determining the momentary envelope value (E) of the input drive signal; and

switching amplification mode device (104;

105,106) for switching to one of the at least three amplification modes depending on the determined momentary envelope value (E) received from the determining device (102, 103).

11. The system according to claim 10, wherein the switching amplification mode device comprises:

switching device (104) switching the power amplification system to a first amplification mode if the momentary envelope value (E) is determined to be within a first amplification interval, or switching the power amplification system to a second amplification mode if the momentary envelope value (E) is determined to be within a second amplification interval, or switching the power amplification system to a third amplification mode if the momentary envelope value (E) is determined to be within a third amplification interval.

12. The system according to claim 11, wherein if the system is operated in the first amplification mode, an outphasing technique is used for power amplifying the input drive signal.

13. The system according to claim 12, wherein if the system is operated in the second amplification mode, a Dynamic Load modulation technique is used for power amplifying the input drive signal.

14. The system according to claim 13, wherein if the system is operated in the third amplification mode, an Envelope Elimination and Restoration (EER) technique is used for power amplifying the input drive signal.

15. The system according to claim 12, wherein if the system is operated in the second amplification mode, an Envelope Elimination and Restoration (EER) technique is used for power amplifying the input drive signal.

16. The system according to claim 15, wherein if the system is operated in the third amplification mode, a Dynamic Load technique is used for power amplifying the input drive signal.

19. A radio base station in a mobile radio telecommunication network, wherein said base station comprises an amplifier system according to any of claims 10-18.

20. A switching amplification mode device (104;

105,106) in a power amplifying system (100) for power amplifying an input drive signal (S_in) to the system, which system is arranged to operate in at least three different power amplification modes, wherein each amplification mode is dedicated to operate within a pre-determined amplification interval, said system (100) comprising determining device (102, 103) for determining the momentary envelope value (E) of the input drive signal, wherein the switching amplification mode device (104;

105,106) is arranged to switch the system to operate in one of the at least three amplification modes depending on the momentary envelope value (E) received from the determining device (102, 103).

21. The switching amplification mode device according to claim 20, wherein the switching device (104) is arranged to switching the power amplification system to a first amplification mode if the momentary envelope value (E) is determined to be within a first amplification interval, or switching the power amplification system to a second amplification mode if the momentary envelope value (E) is determined to be within a second amplification interval, or switching the power amplification system to a third amplification mode if the momentary envelope value (E) is determined to be within a third amplification interval.

22. The switching amplification mode device according to claim 21, wherein if the system is operated in the first amplification mode, an outphasing technique is used for power amplifying the input drive signal.

23. The switching amplification mode device according to claim 22, wherein if the system is operated in the second amplification mode, a Dynamic Load modulation technique is used for power amplifying the input drive signal.

24. The switching amplification mode device according to claim 23, wherein if the system is operated in the third amplification mode, an Envelope Elimination and Restoration (EER) technique is used for power amplifying the input drive signal.

25. The switching amplification mode device according to claim 22, wherein if the system is operated in the second amplification mode, an Envelope Elimination and Restoration (EER) technique is used for power amplifying the input drive signal.

26. The switching amplification mode device according to claim 25, wherein if the system is operated in the third amplification mode, a Dynamic Load technique is used for power amplifying the input drive signal.