Power amplifiers with discrete power control

• US 7,952,433 B2
• Filed: 11/17/2009
• Issued: 05/31/2011
• Est. Priority Date: 11/25/2008
• Status: Expired due to Fees

• Current Assignee: Samsung Electronics Limited (Samsung Electronics Co. Ltd.), Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Samsung Electronics Co. Ltd., Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Lee, Chang-Ho, An, Kyu Hwan, Lee, Dong Ho, Laskar, Joy
• Primary Examiner(s): Nguyen; Khanh V
• Application Number:
  US12/620,476
• Publication Number:
  US 20100127780A1
• Time in Patent Office: 560 Days
• Field of Search: 330/51, 330/124.R, 330/295, 330/302
• US Class Current: 330/295
• CPC Class Codes: H03F 1/0266 by using a signal derived from the input signal
• CPC Class Codes: H03F 1/0277 Selecting one or more amplifiers from a plurality of amplifiers
• CPC Class Codes: H03F 1/223 with MOSFET's
• CPC Class Codes: H03F 2200/105 A non-specified detector of the power of a signal being used in an amplifying circuit
• CPC Class Codes: H03F 2200/222 A circuit being added at the input of an amplifier to adapt the input impedance of the amplifier
• CPC Class Codes: H03F 2200/318 A matching circuit being used as coupling element between two amplifying stages
• CPC Class Codes: H03F 2200/387 A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier
• CPC Class Codes: H03F 2200/541 Transformer coupled at the output of an amplifier
• CPC Class Codes: H03F 2200/543 A transmission line being used as coupling element between two amplifying stages
• CPC Class Codes: H03F 2203/21103 An impedance adaptation circuit being added at the input of a power amplifier stage
• CPC Class Codes: H03F 2203/21118 An input signal dependant signal being measured by power measuring at the input of a power amplifier
• CPC Class Codes: H03F 2203/21139 An impedance adaptation circuit being added at the output of a power amplifier stage
• CPC Class Codes: H03F 2203/7206 the gated amplifier being switched on or off by a switch in the bias circuit of the amplifier controlling a bias voltage in the amplifier
• CPC Class Codes: H03F 2203/7236 the gated amplifier being switched on or off by putting into parallel or not, by choosing between amplifiers by (a ) switch(es)
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03F 3/72 Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal

Abstract

Systems and methods are provided for power amplifiers with discrete power control. The systems and methods may include a plurality of unit power amplifiers; a plurality of primary windings, wherein each primary winding is connected to at least one respective output port of a respective one the plurality of unit power amplifiers; a secondary winding inductively coupled to the plurality of primary windings, where the secondary winding provides an overall output; a bias controller, where the bias controller provides a respective bias voltage based at least in part on a level of output power to one or more of the plurality of unit power amplifiers; and a switch controller, where the switch controller operates to activate or deactivate at least one of the plurality of unit power amplifiers via a respective control signal.

Claims

1. A power amplifier system, comprising:

a plurality of unit power amplifiers, wherein each unit power amplifier includes at least one respective output port, at least one respective bias control port, and at least one respective switch control port;

a plurality of primary windings, wherein each primary winding is connected to the at least one respective output port of a respective one of the plurality of unit power amplifiers;

a secondary winding inductively coupled to the plurality of primary windings, wherein the secondary winding provides an overall output;

a bias controller, wherein the bias controller provides, based at least in part on a level of output power, a respective bias voltage to one or more of the plurality of unit power amplifiers via the at least one respective bias control port; and

a switch controller, wherein the switch controller operates to activate or deactivate at least one of the plurality of unit power amplifiers via a respective control signal to the respective switch control port.

2. The power amplifier system of claim 1, wherein the plurality of unit power amplifiers operate in accordance with the respective bias voltage from the bias controller.

3. The power amplifier system of claim 1, wherein the operation of the respective unit power amplifier in accordance with the respective bias voltage is characterized by an efficiency of the respective unit power amplifier.

4. The power amplifier system of claim 1, wherein the secondary winding provides an overall output having an associated output power level, wherein one or both of the respective bias voltage or the respective control signal are responsive at least in part to the output power level.

5. The power amplifier system of claim 4, wherein the output power level is within one of a plurality of output power ranges, including at least a first power output range and a second power output range lower than the first power output range, the first power output range defining a first operational mode, and the second power output range defining a second operational mode,

wherein for the first operational mode, the switch controller activates a first number of the plurality of unit power amplifiers, and

wherein for the second operational mode, the switch controller activates a second number of the plurality of power amplifiers, the second number less than the first number.

6. The power amplifier system of claim 5,

wherein for the first operational mode, the respective bias voltage for the respective activated ones of the plurality of unit power amplifiers is a first constant voltage, and

wherein for the second operational mode, the respective bias voltage for the respective activated ones of the plurality of unit power amplifiers is a second constant voltage.

7. The power amplifier system of claim 5,

wherein for the first operational mode, the respective bias voltage for the respective activated ones of the plurality of unit power amplifiers varies within a first bias voltage range according to the output power level,

wherein for the second operational mode, the respective bias voltage for the respective activated ones of the plurality of unit power amplifiers varies within a second bias voltage range according to the output power level.

8. The power amplifier system of claim 5,

wherein the plurality of output power ranges further includes a third power output range less than the second power output range, the third power output range defining a third operational model,

wherein for the third operational mode, the switch controller activates a third number of the plurality of unit power amplifiers, the third number less than the second number.

9. The power amplifier system of claim 1, wherein each unit power amplifier comprises a respective gain stage and a respective switch stage, wherein the respective gain stage provides the at least respective bias control port, and wherein the respective switch stage provides the at least one respective switch control port.

10. The power amplifier system of claim 9, wherein if the switch controller deactivates a respective unit power amplifier of the plurality of unit power amplifiers, then a respective output of the respective gain stage is isolated from the at least one respective output port of the respective unit power amplifier.

11. The power amplifier system of claim 9, wherein the respective gain stage includes a respective first transistor having a first gate or base, a first source or emitter, and a first drain or collector, wherein the respective switch stage includes a respective second transistor having a second gate or base, a second source or emitter, and a second drain or collector, wherein the first gate or base is associated with the at least one respective bias control port, wherein the first source or emitter is connected to ground, wherein the first drain or collector is connected to the second source or emitter, wherein the second gate or base is associated with the at least one respective switch control port, and the second drain or collector is associated with the at least one respective output port.

12. The power amplifier system of claim 11, wherein the first gate or base is connected to the bias controller via a first bias resistor, wherein the second gate or base is connected to the switch controller via a second bias resistor.

13. The power amplifier system of claim 11, wherein the second drain or collector is connected to a DC voltage supply.

14. The power amplifier system of claim 1, wherein each of the primary windings includes a single turn, and wherein the single secondary winding includes more than one turn.

15. A power amplifier system, comprising:

a plurality of unit power amplifiers, wherein each unit power amplifier includes a respective input port, a respective output port, a respective bias control port, and a respective switch control port;

a transformer comprising a plurality of primary windings that is inductively coupled to a single secondary winding, wherein each primary winding is connected to a respective output port of the respective plurality of unit power amplifiers; and

one or more controllers for biasing and activating ones of the plurality of unit power amplifiers, wherein respective outputs from one or more activated ones of the plurality of unit power amplifiers are provided to the respective primary windings, which induce voltage on the secondary winding to provide an overall output.

16. The power amplifier system of claim 15, wherein the biasing and activating of the ones of the plurality of unit power amplifiers are responsive at least in part on an output power level associated with the overall output.

17. The power amplifier system of claim 16, wherein the output power level is within one of a plurality of output power ranges, including at least a first power output range and a second power output range lower than the first power output range, the first power output range defining a first operational mode, and the second power output range defining a second operational mode,

wherein for the first operational mode, a first number of the plurality of unit power amplifiers are activated by the one or more controllers, and

wherein for the second operational mode, a second number of the plurality of power amplifiers are activated by the one or more controllers, the second number less than the first number.

18. The power amplifier system of claim 17,

wherein for the first operational mode, the biasing for the respective activated ones of the plurality of unit power amplifiers is at a first constant voltage, and

wherein for the second operational mode, the biasing for the respective activated ones of the plurality of unit power amplifiers is at a second constant voltage.

19. The power amplifier system of claim 17,

wherein for the first operational mode, the biasing for the respective activated ones of the plurality of unit power amplifiers varies within a first bias voltage range according to the output power level,

wherein for the second operational mode, the respective bias voltage for the respective activated ones of the plurality of unit power amplifiers varies within a second bias voltage range according to the output power level.

20. The power amplifier system of claim 17, wherein each unit power amplifier comprises a respective gain stage and a respective switch stage, wherein the respective gain stage provides the respective bias control port, and wherein the respective switch stage provides the respective switch control port, wherein the respective gain stage includes a respective first transistor having a first gate or base, a first source or emitter, and a first drain or collector, wherein the respective switch stage includes a respective second transistor having a second gate or base, a second source or emitter, and a second drain or collector, wherein the first gate or base is associated with the at least one respective bias control port, wherein the first source or emitter is connected to ground, wherein the first drain or collector is connected to the second source or emitter, wherein the second gate or base is associated with the at least one respective switch control port, and the second drain or collector is associated with the at least one respective output port.