Reconfigurable load modulation amplifier

Patent metadata

Field	Value
Publication number	US-9484865-B2
Application number	US-201414501453-A
Country	US
Kind code	B2
Filing date	Sep 30, 2014
Priority date	Sep 30, 2013
Publication date	Nov 1, 2016
Grant date	Nov 1, 2016

Abstract

A reconfigurable load modulation amplifier having a carrier amplifier and a peak amplifier that are coupled in parallel is disclosed. The peak amplifier provides additional power amplification when the carrier amplifier is driven into saturation. A quadrature coupler coupled between the carrier amplifier and the peak amplifier is configured to combine power from both the carrier amplifier and the peak amplifier for output through an output load terminal. The reconfigurable load modulation amplifier further includes control circuitry coupled to an isolation port of the quadrature coupler and configured to provide adjustable impedance at the isolation port of the quadrature coupler. As such, impedance at the isolation port of the quadrature coupler is tunable such that at least a carrier or peak amplifier is presented with a quadrature coupler load impedance that ranges from around about half an output load termination impedance to around about twice the output load termination impedance.

First claim

What is claimed is:

1. A reconfigurable load modulation amplifier comprising:
a carrier amplifier;
a peak amplifier coupled in parallel with the carrier amplifier;
a quadrature coupler configured to combine power from both the carrier amplifier and the peak amplifier for output through an output load terminal; and
control circuitry coupled to an isolation port of the quadrature coupler and configured to generate a control signal that tunes adjustable impedance at the isolation port of the quadrature coupler such that the carrier amplifier is presented with a quadrature coupler load impedance that is below a terminal load impedance at the output load terminal in response to decreasing output power at the output load terminal.

2. The reconfigurable load modulation amplifier of claim 1 wherein the carrier amplifier is coupled to the output load terminal through 0° phase shift ports of the quadrature coupler.

3. The reconfigurable load modulation amplifier of claim 1 wherein the carrier amplifier is coupled to the output load terminal through 90° phase shift ports of the quadrature coupler.

4. The reconfigurable load modulation amplifier of claim 1 wherein the control circuitry comprises a switch network that is configured to receive the control signal for adjusting the adjustable impedance presented to the isolation port of the quadrature coupler.

5. The reconfigurable load modulation amplifier of claim 4 wherein the switch network comprises a micro-electro-mechanical systems (MEMs) switch network.

6. The reconfigurable load modulation amplifier of claim 4 wherein the switch network is a silicon-on-insulator (SOI) switch network.

7. The reconfigurable load modulation amplifier of claim 1 wherein impedance at the isolation port of the quadrature coupler is tunable to impedance values above a terminal load impedance at the output load terminal.

8. The reconfigurable load modulation amplifier of claim 1 wherein impedance at the isolation port of the quadrature coupler is tunable to impedance values below the terminal load impedance at the output load terminal.

9. The reconfigurable load modulation amplifier of claim 1 wherein impedance at the isolation port of the quadrature coupler is continuously tunable such that the carrier amplifier is presented with the quadrature coupler load impedance that ranges from around about half an output load termination impedance to around about twice the output load termination impedance.

10. The reconfigurable load modulation amplifier of claim 1 wherein impedance at the isolation port of the quadrature coupler is continuously tunable such that the peak amplifier is presented with a quadrature coupler load impedance that ranges from around about half an output load termination impedance to around about twice the output load termination impedance.

11. The reconfigurable load modulation amplifier of claim 1 wherein the quadrature coupler load impedance is around about half the terminal load impedance at the output load terminal.

12. The reconfigurable load modulation amplifier of claim 1 wherein impedance at the isolation port of the quadrature coupler is tunable such that the carrier amplifier is presented with a quadrature coupler load impedance that is above a terminal load impedance at the output load terminal.

13. The reconfigurable load modulation amplifier of claim 12 wherein the quadrature coupler load impedance is around about twice a terminal load impedance at the output load terminal.

14. The reconfigurable load modulation amplifier of claim 1 wherein a total load impedance presented to the carrier amplifier is relatively substantially higher than a nominal saturated load impedance of the carrier amplifier.

15. The reconfigurable load modulation amplifier of claim 1 wherein a total load impedance presented to the carrier amplifier is relatively substantially lower than a nominal saturated load impedance of the carrier amplifier.

16. The reconfigurable load modulation amplifier of claim 1 wherein a total load impedance presented to the carrier amplifier is relatively substantially higher than a nominal saturated load impedance of the reconfigurable load modulation amplifier at around full power.

17. The reconfigurable load modulation amplifier of claim 1 wherein a total load impedance presented to the carrier amplifier is relatively substantially lower than a nominal saturated load impedance of the reconfigurable load modulation amplifier at around full power.

18. The reconfigurable load modulation amplifier of claim 1 further including voltage standing wave ratio (VSWR) detection circuitry configured to detect a VSWR mismatch condition associated with the output load terminal.

19. The reconfigurable load modulation amplifier of claim 18 wherein the VSWR detection circuitry is configured to determine if an antenna impedance is below or higher than a nominal output load termination impedance.

20. The reconfigurable load modulation amplifier of claim 18 wherein the VSWR detection circuitry is configured to detect that an antenna impedance is less than a nominal output load termination impedance, and then set an isolation impedance of the quadrature coupler to a termination impedance range that is greater than the nominal output load termination impedance to improve isolation between the carrier amplifier and peak amplifier for improving load insensitive load modulation operation.

21. The reconfigurable load modulation amplifier of claim 18 wherein the VSWR detection circuitry is configured to detect that an antenna impedance is greater than a nominal output load termination impedance, and then set an isolation impedance of the quadrature coupler to a termination impedance range that is less than the nominal output load termination impedance to improve isolation between the carrier amplifier and the peak amplifier for improving load insensitive load modulation operation.

22. The reconfigurable load modulation amplifier of claim 18 wherein the VSWR detection circuitry is configured to detect that an antenna impedance is less than a nominal output load termination impedance, and then set an isolation impedance of the quadrature coupler to a termination impedance range that is less than the nominal output load termination impedance to improve isolation between the carrier amplifier and the peak amplifier for improving load insensitive inverted phase load modulation operation.

23. The reconfigurable load modulation amplifier of claim 18 wherein the VSWR detection circuitry is configured to detect that an antenna impedance is greater than a nominal output load termination impedance, and then set an isolation impedance of the quadrature coupler to a termination impedance range that is greater than the nominal output load termination impedance to improve isolation between the carrier amplifier and the peak amplifier for improving load insensitive inverted phase load modulation operation.

24. The reconfigurable load modulation amplifier of claim 18 wherein the VSWR detection circuitry is configured to detect phase and amplitude of a signal associated with power output through the output load terminal.

25. The reconfigurable load modulation amplifier of claim 1 wherein the carrier amplifier is configured to operate from a drain voltage modulation.

26. The reconfigurable load modulation amplifier of claim 1 wherein the peak amplifier is configured to operate fro

Assignees

• Rf Micro Devices Inc
• Qorvo Us Inc

Inventors

• Kobayashi Kevin Wesley
• Jeon Hamhee

Classifications

• H03F1/3247

  using feedback acting on predistortion circuits (H03F1/3264 takes precedence) · CPC title

• H03F1/0233

  by using a signal derived from the output signal, e.g. bootstrapping the voltage supply · CPC title

• H03F3/19

  with semiconductor devices only · CPC title

• H03F1/56

  Modifications of input or output impedances, not otherwise provided for · CPC title

• H03F3/193

  with field-effect devices (H03F3/195 takes precedence) · CPC title