Calibrating a power amplifier such as in a remote unit in a wireless distribution system (WDS)

• US 10,298,185 B2
• Filed: 04/27/2018
• Issued: 05/21/2019
• Est. Priority Date: 05/31/2017
• Status: Active Grant

• Current Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Original Assignee: Corning Optical Communications LLC (Corning Incorporated)
• Inventors: Gutman, Amit, Kaduri, Shlomi, Ziv, Roi Yosy
• Primary Examiner(s): Trinh, Tan H
• Application Number:
  US15/964,755
• Publication Number:
  US 20180351512A1
• Time in Patent Office: 389 Days
• Field of Search: 4552321, 4552401, 455341, 455355, 4551272, 455103, 455 73, 4551142, 455 78, 4552501, 375219, 330136, 330277, 330296
• CPC Class Codes: H03F 1/0261 with control of the polarisation voltage or current, e.g. gliding Class A
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/245 with semiconductor devices only
• CPC Class Codes: H03F 3/68 Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics power amplifiers using a combination of several semiconductor amplifiers H03F3/211; combinations of amplifiers using coupling networks with distributed constants H03F3/602
• CPC Class Codes: H04B 17/13 of power amplifiers, e.g. gain or non-linearity
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition

Abstract

Embodiments of the disclosure relate to calibrating a power amplifier. The power amplifier calibration circuit is configured to provide a plurality of bias signal combinations each including a respective first bias signal and a respective second bias signal to the power amplifier. Power amplifier performance parameters for each of the bias signal combinations can be measured and provided to a control circuit in the power amplifier calibration circuit. The control circuit is configured to rank the measured power amplifier performance parameters based on predefined ranking criteria and determines a selected bias signal combination that can optimize the power amplifier performance parameters of the power amplifier. As such, it is possible to calibrate the power amplifier to operate at a balanced performance level, thus helping to improve radio frequency (RF) coverage and performance of the remote unit in a wireless distribution system (WDS).

Claims

1. A method for calibrating an amplifier, comprising:

providing a plurality of bias signal combinations to an amplifier configured to amplify an input signal to generate an output signal, wherein each of the plurality of bias signal combinations comprises a respective first bias signal and a respective second bias signal to be provided to the amplifier for controlling a first amplifier performance parameter and a second amplifier performance parameter in the output signal, respectively;

receiving a plurality of performance indication signals comprising a plurality of measurements corresponding to the plurality of bias signal combinations, respectively, wherein each of the plurality of measurements comprises the first amplifier performance parameter and the second amplifier performance parameter;

ranking the plurality of measurements;

determining a selected bias signal combination among the plurality of bias signal combinations corresponding to a selected ranked measurement among the plurality of measurements; and

controlling the amplifier to operate based on the selected bias signal combination.

2. The method of claim 1, further comprising:

representing the respective first bias signal by a first digital word; and

representing the respective second bias signal by a second digital word.

3. The method of claim 1, further comprising:

receiving a modulated broadband input signal, wherein the modulated broadband input signal comprises a first signal in a first signal frequency and a second signal in a second signal frequency; and

generating a modulated broadband output signal, wherein the modulated broadband output signal comprises the first signal and the second signal.

4. The method of claim 1, further comprising:

receiving the input signal from a signal generator communicatively coupled to the amplifier; and

providing the output signal to a spectrum analyzer communicatively coupled to the amplifier and a control circuit.

5. The method of claim 4, further comprising:

generating the plurality of measurements corresponding to the plurality of bias signal combinations, respectively;

generating the plurality of performance indication signals comprising the plurality of measurements in association with the plurality of bias signal combinations, respectively; and

providing the plurality of performance indication signals to the control circuit.

6. The method of claim 1, further comprising controlling a third-order intermodulation (IMD3) and an adjacent channel power ratio (ACPR) in the output signal based on the respective first bias signal and the respective second bias signal.

7. A method for calibrating an amplifier, comprising:

receiving a modulated broadband input signal, wherein the modulated broadband input signal comprises a first signal in a first signal frequency and a second signal in a second signal frequency;

providing a plurality of bias signal combinations to an amplifier configured to amplify an input signal to generate an output signal, wherein each of the plurality of bias signal combinations comprises a respective first bias signal and a respective second bias signal to be provided to the amplifier for controlling a first amplifier performance parameter and a second amplifier performance parameter in the output signal, respectively;

receiving a plurality of performance indication signals comprising a plurality of measurements corresponding to the plurality of bias signal combinations, respectively, wherein each of the plurality of measurements comprises the first amplifier performance parameter and the second amplifier performance parameter;

ranking the plurality of measurements; and

determining a selected bias signal combination among the plurality of bias signal combinations corresponding to a selected ranked measurement among the plurality of measurements.

8. The method of claim 7, further comprising generating a modulated broadband output signal, wherein the modulated broadband output signal comprises the first signal and the second signal.

9. The method of claim 8, further comprising:

representing the respective first bias signal by a first digital word; and

representing the respective second bias signal by a second digital word.

10. The method of claim 7, further comprising receiving the input signal from a signal generator communicatively coupled to the amplifier.

11. The method of claim 10, further comprising providing the output signal to a spectrum analyzer communicatively coupled to the amplifier and a control circuit.

12. The method of claim 11, further comprising:

generating the plurality of measurements corresponding to the plurality of bias signal combinations, respectively;

generating the plurality of performance indication signals comprising the plurality of measurements in association with the plurality of bias signal combinations, respectively; and

providing the plurality of performance indication signals to the control circuit.

13. The method of claim 7, further comprising controlling a third-order intermodulation (IMD3) and an adjacent channel power ratio (ACPR) in the output signal based on the respective first bias signal and the respective second bias signal.

14. A method for calibrating an amplifier, comprising:

providing a plurality of bias signal combinations to an amplifier configured to amplify an input signal to generate an output signal, wherein each of the plurality of bias signal combinations comprises a respective first bias signal and a respective second bias signal to be provided to the amplifier for controlling a first amplifier performance parameter and a second amplifier performance parameter in the output signal, respectively;

receiving a plurality of performance indication signals comprising a plurality of measurements corresponding to the plurality of bias signal combinations, respectively, wherein each of the plurality of measurements comprises the first amplifier performance parameter and the second amplifier performance parameter;

ranking the plurality of measurements;

determining a selected bias signal combination among the plurality of bias signal combinations corresponding to a selected ranked measurement among the plurality of measurements; and

controlling a third-order intermodulation (IMD3) and an adjacent channel power ratio (ACPR) in the output signal based on the respective first bias signal and the respective second bias signal.

15. The method of claim 14, further comprising receiving the plurality of measurements each comprising a respective IMD3 and a respective ACPR of the output signal.

16. The method of claim 14, further comprising for each measurement among the plurality of measurements:

calculating a respective IMD3 margin between a predefined IMD3 threshold and the respective IMD3;

calculating a respective ACPR margin between a predefined ACPR threshold and the respective ACPR;

scaling the respective IMD3 margin based on a predefined IMD3 scale factor to generate a respective scaled IMD3 margin;

scaling the respective ACPR margin based on a predefined ACPR scale factor to generate a respective scaled ACPR margin;

determining a respective minimal margin corresponding to a smaller scaled margin between the respective scaled IMD3 margin and the respective scaled ACPR margin; and

storing the selected bias signal combination in association with the respective minimal margin.