Power amplifier self-heating compensation circuit

Patent metadata

Field	Value
Publication number	US-10873308-B2
Application number	US-201916676219-A
Country	US
Kind code	B2
Filing date	Nov 6, 2019
Priority date	Feb 28, 2017
Publication date	Dec 22, 2020
Grant date	Dec 22, 2020

Abstract

Temperature compensation circuits and methods for adjusting one or more circuit parameters of a power amplifier (PA) to maintain approximately constant Gain versus time during pulsed operation sufficient to substantially offset self-heating of the PA. Some embodiments compensate for PA Gain “droop” due to self-heating using a Sample and Hold (S&H) circuit. The S&H circuit samples and holds an initial temperature of the PA at commencement of a pulse. Thereafter, the S&H circuit generates a continuous measurement that corresponds to the temperature of the PA during the remainder of the pulse. A Gain Control signal is generated that is a function of the difference between the initial temperature and the operating temperature of the PA as the PA self-heats for the duration of the pulse. The Gain Control signal is applied to one or more adjustable or tunable circuits within a PA to offset the Gain droop of the PA.

First claim

What is claimed is:

1. A compensation circuit configured to monitor a target circuit having one or more performance parameters affected by heating during operation of the target circuit, wherein the compensation circuit is configured to be coupled to and adjust one or more circuit parameters of the target circuit sufficient to substantially offset the effect of heating during operation of the target circuit on the one or more performance parameters, the compensation circuit including:
(a) at least one proximate sensor located relative to the target circuit so as to measure a temperature T(p) of the target circuit;
(b) at least one distant sensor located relative to the target circuit so as to measure a temperature T(d);
(c) a comparison circuit, coupled to at least one proximate sensor and at least one distant sensor, for determining a signal ΔT=T(p)−T(d); and
(d) a mapping circuit, coupled to the comparison circuit, for receiving values of the signal ΔT and mapping the values of the signal ΔT to corresponding control signal values, the control signal values being configured to be coupled to and adjust the one or more circuit parameters of the target circuit.

2. The invention of claim 1 , further including a sample and hold circuit, coupled to at least one distant sensor, for sampling and holding T(d) near the commencement of operation of the target circuit.

3. The invention of claim 1 , wherein the target circuit includes an amplifier and one of the performance parameters is at least one of a Gain or output power of the amplifier during operation of the amplifier.

4. The invention of claim 1 , wherein the target circuit includes an amplifier having at least one amplifier stage configured to receive an input radio frequency signal and output an amplified radio frequency signal, and wherein the control signal values are configured to be coupled to and adjust at least one of: a bias circuit for one or more amplifier stages; one or more impedance matching networks affecting the input radio frequency signal and/or the amplified radio frequency signal; one or more auxiliary amplifier stages for amplifying the input radio frequency signal and/or the amplified radio frequency signal; one or more attenuation circuits affecting the amplitude of the input radio frequency signal and/or the amplified radio frequency signal; one or more voltage and/or current supply circuits within or to the amplifier.

5. An integrated circuit including (1) an amplifier having a Gain that droops during operation and (2) a compensation circuit, the compensation circuit including:
(a) at least one proximate sensor located with respect to the amplifier so as to measure a temperature T(p) of the amplifier;
(b) at least one distant sensor located relative to the amplifier so as to measure a temperature T(d);
(c) a comparison circuit, coupled to at least one proximate sensor and at least one distant sensor, for determining a signal ΔT=T(p)−T(d); and
(d) a mapping circuit, coupled to the comparison circuit and to the amplifier, for receiving values of the signal ΔT and mapping the values of the signal ΔT to corresponding control signal values, the control signal values being coupled to one or more circuits on the integrated circuit to adjust one or more circuit parameters of the one or more circuits to significantly offset the effect of heating during operation of the amplifier on the Gain of the amplifier.

6. The invention of claim 5 , further including a sample and hold circuit, coupled to at least one distant sensor, for sampling and holding T(d) near the commencement of operation of the amplifier.

7. The invention of claim 5 , wherein the control signal values are coupled to and adjust at least one of a Gain or output power of the amplifier during operation of the amplifier.

8. The invention of claim 5 , wherein the amplifier includes at least one amplifier stage configured to receive an input radio frequency signal and output an amplified radio frequency signal, and wherein the control signal values are coupled to and adjust at least one of: a bias circuit for one or more amplifier stages; one or more impedance matching networks affecting the input radio frequency signal and/or the amplified radio frequency signal; one or more auxiliary amplifier stages for amplifying the input radio frequency signal and/or the amplified radio frequency signal; one or more attenuation circuits affecting the amplitude of the input radio frequency signal and/or the amplified radio frequency signal; one or more voltage and/or current supply circuits within or to the amplifier.

9. A method for compensating a target circuit having one or more performance parameters affected by heating during operation of the target circuit, including:
(a) measuring, at a location proximate to the target circuit, a temperature T(p) of the target circuit during operation of the target circuit;
(b) measuring, at a location distant from the target circuit, a temperature T(d) during operation of the target circuit;
(c) determining a signal ΔT=T(p)−T(d);
(d) mapping, in a mapping circuit, values of the signal ΔT to corresponding control signal values; and
(f) applying the control signal values to adjust the one or more circuit parameters of the target circuit.

10. The method of claim 9 , further including sampling and holding T(d) near the commencement of operation of the target circuit.

11. The method of claim 9 , wherein the target circuit includes an amplifier and one of the performance parameters is at least one of a Gain or output power of the amplifier during operation of the amplifier.

12. The method of claim 9 , wherein the target circuit includes an amplifier having at least one amplifier stage configured to receive an input radio frequency signal and output an amplified radio frequency signal, and wherein the control signal values adjust at least one of: a bias circuit for one or more amplifier stages; one or more impedance matching networks affecting the input radio frequency signal and/or the amplified radio frequency signal; one or more auxiliary amplifier stages for amplifying the input radio frequency signal and/or the amplified radio frequency signal; one or more attenuation circuits affecting the amplitude of the input radio frequency signal and/or the amplified radio frequency signal; one or more voltage and/or current supply circuits within or to the amplifier.

13. A method for compensating an integrated circuit including (1) an amplifier having a Gain that droops during operation and (2) a compensation circuit, the method including:
(a) providing at least one proximate sensor located with respect to the amplifier so as to measure a temperature T(p) of the amplifier;
(b) providing at least one distant sensor located relative to the amplifier so as to measure a temperature T(d);
(c) providing a comparison circuit, coupled to at least one proximate sensor and at least one distant sensor, for determining a signal ΔT=T(p)−T(d);
(d) mapping, in a mapping circuit coupled to the comparison circuit, values of the signal ΔT to corresponding control signal values; and
(e) coupling the control signal values to one or more circuits on the integrated circuit to adjust one or more circuit parameters of the one or more circuits to significantly offset droop in the Gain of the amplifier.

14. The method of claim 13 , further including providing a sample and hold circuit, coupled to at least one distant sensor, for sampling and holding T(d) near the commencement of operation of the amplifier.

15. The method of claim 13 , wherein one of the circuit parameters is at least one of a Gain

Assignees

• Psemi Corp

Inventors

• Ranta Tero Tapio
• Bargroff Keith
• Murphy Christopher C
• Englekirk Robert Mark

Classifications

• H03F3/19

  with semiconductor devices only · CPC title

• H03F2200/451

  the amplifier being a radio frequency amplifier · CPC title

• H03F1/303

  using a switching device (H03F1/305, H03F3/005, H03F3/38 take precedence) · CPC title

• H03F2200/468

  the temperature being sensed · CPC title

• H03F2200/222

  A circuit being added at the input of an amplifier to adapt the input impedance of the amplifier · CPC title