# US 10,873,308 B2 · Power amplifier self-heating compensation circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,873,308 B2 - Document ID: US10873308B2 - Status: Granted - Kind: B2 - Application number: 16/676,219 - Filed: 2019-11-06 - Published: 2020-03-05 - Granted: 2020-12-22 - Earliest claimed: 2017-02-28 - Assignees: pSemi Corporation - Applicants: pSemi Corporation - Inventors: Tero Tapio Ranta; Keith Bargroff; Christopher C. Murphy; Robert Mark Englekirk - Web page: https://patentgrep.com/patent/US10873308B2 ## CPC - H03G 3/3042: {in modulators, frequency-changers, transmitters or power amplifiers} - H03F 1/30: Modifications of amplifiers to reduce influence of variations of temperature or supply voltage {or other physical parameters (in differential amplifiers H03F3/45479)} - H03F 1/303: {using a switching device (H03F1/305, H03F3/005, H03F3/38 take precedence)} - H03F 1/304: {and using digital means} - H03F 1/56: Modifications of input or output impedances, not otherwise provided for - H03F 3/19: with semiconductor devices only - H03F 3/21: with semiconductor devices only {(H03F3/245 takes precedence)} - H03F 3/245: {with semiconductor devices only} - H03G 3/3036: {in high-frequency amplifiers or in frequency-changers (H03G3/3052, H03G3/32, H03G3/34 take precedence)} - H03F 2200/222: A circuit being added at the input of an amplifier to adapt the input impedance of the amplifier - H03F 2200/318: A matching circuit being used as coupling element between two amplifying stages - H03F 2200/387: A circuit being added at the output of an amplifier to adapt the output impedance of the amplifier - H03F 2200/447: the amplifier being protected to temperature influence - H03F 2200/451: the amplifier being a radio frequency amplifier - H03F 2200/468: the temperature being sensed - H03G 2201/106: being attenuating element - H03G: CONTROL OF AMPLIFICATION - H03F: AMPLIFIERS ## 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. ## Claims ### Claim 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. ### Claim 2 (depends on 1) 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. ### Claim 3 (depends on 1) 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. ### Claim 4 (depends on 1) 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. ### Claim 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. ### Claim 6 (depends on 5) 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. ### Claim 7 (depends on 5) 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. ### Claim 8 (depends on 5) 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. ### Claim 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. ### Claim 10 (depends on 9) The method of claim 9, further including sampling and holding T(d) near the commencement of operation of the target circuit. ### Claim 11 (depends on 9) 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. ### Claim 12 (depends on 9) 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. ### Claim 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. ### Claim 14 (depends on 13) 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. ### Claim 15 (depends on 13) The method of claim 13, wherein one of the circuit parameters is at least one of a Gain or output power of the amplifier during operation of the amplifier. ### Claim 16 (depends on 13) The method of claim 13, 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 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.