Rf Power Amplifiers

• US 20080278236A1
• Filed: 05/04/2007
• Published: 11/13/2008
• Est. Priority Date: 05/05/2006
• Status: Active Grant

• Current Assignee: Astrium Limited (Airbus SE)
• Original Assignee: Astrium Limited (Airbus SE)
• Inventors: Seymour, Christopher David
• Granted Patent: US 8,208,874 B2
• Time in Patent Office: Days
• US Class Current: 330/279
• CPC Class Codes: H03F 1/0211 with control of the supply voltage or current
• CPC Class Codes: H03F 1/0222 by using a signal derived from the input signal
• CPC Class Codes: H03F 1/0244 Stepped control
• CPC Class Codes: H03F 1/0266 by using a signal derived from the input signal
• CPC Class Codes: H03F 1/32 Modifications of amplifiers to reduce non-linear distortion by negative feedback H03F1/34
• 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 2200/468 the temperature being sensed
• CPC Class Codes: H03F 2201/3203 the amplifier comprising means for back off control in order to reduce distortion
• CPC Class Codes: H03F 3/24 of transmitter output stages

Abstract

A Solid State Power Amplifier (SSPA) for powering a single element of a multi-element antenna, the SSPA comprising:

an RF amplifier, having a signal amplifying path that includes preamplifier, driver amplifier and a power output stage;

an Electronic Power Conditioner (EPC) for providing a variable value of DC voltage for powering the power output stage of the RF amplifier;

a control ASIC for receiving an input power signal of the RF amplifier for providing a voltage control signal to the EPC to determine the value of the DC voltage, the control ASIC addressing an EEPROM holding a collection of control words that define output values of a control output signal for varying values of said input power, such that the value of the DC voltage to the power output stage is varied so as to control the gain compression of the RF amplifier for varying values of input power in order to maintain constant amplifier linearity.

Claims

1. An amplifier system for powering an element of an antenna, the amplifier system comprising:

an RF amplifier means, having a signal amplifying path that includes at least a power output stage;

a power supply means for providing a variable value of DC voltage for powering at least said power output stage of said RF amplifier means;

a control means for receiving as a control input an input power signal of said RF amplifier means, for providing, in response to the control input, a voltage control signal to said power supply means to determine the value of said DC voltage;

and said control means being arranged such that the value of said DC voltage to said power output stage is varied so as to control the gain compression of said RF amplifier means for varying values of said input power in order to regulate at least one of amplifier linearity, amplifier efficiency, and thermal dissipation of said RF amplifier means.

2. An amplifier system according to claim 1, wherein amplifier linearity is maintained constant, or within predetermined limits, over a desired range.

3. An amplifier system according to claim 1, wherein said control means has as a further control input a temperature signal of the RF amplifier means, and the control means being arranged to provide said voltage control signal to the power supply means in dependence both on said temperature signal and said input power signal.

4. An amplifier system according to claim 1, wherein said RF amplifier means include preamplifier means having means to vary at least one of amplifier gain, amplifier gain slope, and transmission phase, and said control means provides at least one control output signal for control of at least one of amplifier gain, amplifier gain slope, and transmission phase.

5. An amplifier system according to claim 1, wherein said RF amplifier means includes a driver stage, said power supply means being arranged to provide said variable value of DC voltage to said driver stage.

6. An amplifier system according to claim 1, wherein the control means is arranged to provide telecommanded signals to said power supply means to determine the value of said DC voltage.

7. An amplifier system according to claim 3, wherein the control means includes storage means that holds a collection of control words that define values of said voltage control signal for varying values of said input power.

8. An amplifier system according to claim 7, wherein said collection of control words define values of said voltage control signal for varying values of both said input power signal and said temperature signal;

and

said control means including circuit means for receiving said control inputs of input power signal and temperature signal and for addressing in response thereto said storage means to access one of said control words, and for providing said voltage control signal with a value determined by said one control word.

9. An amplifier system according to claim 4, wherein said collection of control words define values of said one control output signal for varying values of said input power signal and/or said temperature signal.

18. An amplifier system according to claim 4, wherein the control means includes storage means that holds a collection of control words that define values of said voltage control signal for varying values of said input power.

19. An amplifier system according to claim 18, wherein said collection of control words define values of said one control output signal for varying values of said input power signal and/or said temperature signal.

10. An amplifier system for powering an element of an antenna, the amplifier system comprising:

an RF amplifier means, having a signal amplifying path that includes at least a power output stage;

a power supply means for providing a variable value of DC voltage for powering at least said power output stage of said RF amplifier means;

a control means for receiving as a control input an input power signal from said RF amplifier means, for providing, in response to the control input, a voltage control signal to said power supply means to determine the value of said DC voltage;

and the control means including storage means that holds a collection of control words that define output values of said voltage control signal for varying values of said input power, whereby to vary the value of said DC voltage and thereby control a predetermined parameter of said RF amplifier means.

11. An amplifier system according to claim 10, wherein said control means has as a further control input a temperature signal of said RF amplifier means, wherein said collection of control words define values of said voltage control signal for varying values of both said input power signal and said temperature signal;

and

said control means including circuit means for receiving said control inputs of input power signal and temperature signal and for addressing in response thereto said storage means to access one of said control words, and for providing said voltage control signal with a value determined by said one control word.

12. An amplifier system according to claim 10, wherein said RF amplifier means include preamplifier means having means to vary at least one of amplifier gain, amplifier gain slope, and transmission phase, and said control means provides at least one control output signal for control of at least one of amplifier gain, amplifier gain slope, and transmission phase, and

wherein said collection of control words define values of said one control output signal for varying values of said input power signal and/or said temperature signal.

13. An amplifier system according to claim 10, wherein said power output stage includes at least one power transistor.

14. An amplifier system according to claim 13, wherein said one power transistor comprises an FET.

15. An amplifier system according to claim 10, comprising a solid state power amplifier, including said RF amplifier means and said control means mounted on one or more circuit boards, and said power supply means comprising an Electronic Power Conditioner.

16. An amplifier system according to claim 10, where the antenna is a single element of a multi-element antenna.

20. An amplifier system according to claim 15, where the antenna is a single element of a multi-element antenna.

17. In an amplifier system for powering an element of an antenna, the amplifier system comprising:

an RF amplifier means, having a signal amplifying path that includes at least a power output stage;

a power supply means for providing a DC voltage for powering at least said power output stage of said RF amplifier means;

a method of controlling said RF amplifier means comprising monitoring the input power to said RF amplifier means, and varying in response to said input power the value of said DC voltage, whereby to control the gain compression of said RF amplifier means for varying values of said input power in order to regulate at least one of amplifier linearity, amplifier efficiency, and thermal dissipation of the RF amplifier means.