# US 2008/0186092 A1 · Shared linearity maintenance in power amplifiers > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2008/0186092 A1 - Document ID: US20080186092A1 - Status: Published application - Kind: A1 - Application number: 11/876,484 - Filed: 2007-10-22 - Published: 2008-08-07 - Earliest claimed: 2006-10-26 - Assignees: Infineon Technologies AG - Inventors: Andrea Camuffo; Andreas Langer - Web page: https://patentgrep.com/patent/US20080186092A1 ## CPC - H03F 1/52: Circuit arrangements for protecting such amplifiers {(monitoring arrangements G01R31/28; increasing reliability in communication systems, e.g. using redundancy H04B1/74)} - H03F 1/34: Negative-feedback-circuit arrangements with or without positive feedback (H03F1/02 - H03F1/30, H03F1/38 - H03F1/50, H03F3/50 take precedence {; for rejection of common mode signals H03F3/45479}) - H03F 2200/462: the current being sensed - H03F 2200/471: the voltage being sensed - H03F: AMPLIFIERS ## Abstract In some embodiments, a circuit includes a power amplifier including an input terminal configured to receive an input signal and an output terminal to provide an RF voltage, the output terminal coupled to a load, a current sensor configured to sense the current drawn by the power amplifier and provide a first sensor output signal dependent upon current consumption when the current exceeds a predetermined current threshold, a voltage sensor configured to sense the output power of the power amplifier and provide a second sensor output signal when the RF voltage during up ramp falls below a predetermined threshold voltage, and a summing circuit configured to receive the first and second sensor output signals and provide a feedback signal including a combination of a power dependent contribution and either of a voltage dependent contribution or a current dependent contribution. ## Claims ### Claim 1 A circuit; comprising: a power amplifier including an input terminal configured to receive an input signal and an output terminal to provide an RF voltage, the output terminal coupled to a load; a current sensor configured to sense the current drawn by the power amplifier and provide a first sensor output signal dependent upon current consumption when the current exceeds a predetermined current threshold; a voltage sensor configured to sense the output power of the power amplifier and provide a second sensor output signal when the RF voltage during up ramp falls below a predetermined threshold voltage; and a summing circuit configured to receive the first and second sensor output signals and provide a feedback signal including a combination of a power dependent contribution and either of a voltage dependent contribution or a current dependent contribution. ### Claim 2 (depends on 1) The circuit of claim 1, wherein the power amplifier is coupled to an external power controller using a serial peripheral interface (SPI). ### Claim 3 (depends on 1) The circuit of claim 1, further comprising a serial peripheral interface adapted to receive a signal corresponding to a desired predetermined current threshold. ### Claim 4 (depends on 1) The circuit of claim 1, further comprising a serial peripheral interface adapted to receive a signal corresponding to a desired predetermined threshold voltage. ### Claim 5 A system, comprising: a power amplifier module including a current sensor to sense the current drawn by the amplifier and providing a first sensor output signal dependent upon current consumption when the current exceeds a predetermined current threshold, a voltage sensor to sense the power output of the amplifier and produce a second sensor output signal when the RF voltage during up ramp falls below a predetermined voltage threshold, and a summing circuit configured to receive the first and second sensor output signals and provide a hybrid feedback signal including a combination of a power dependent contribution and either of a voltage dependent contribution or a current dependent contribution; and an automatic power controller coupled to the power amplifier module and configured to receive the hybrid feedback signal having a combination of a power dependent contribution and either of a voltage dependent contribution or a current dependent contribution. ### Claim 6 (depends on 5) The system of claim 5, wherein the automatic power controller is coupled to the power amplifier module using a serial peripheral interface. ### Claim 7 (depends on 5) The system of claim 5, wherein the hybrid feedback signal is received by a front-end circuit including the automatic power controller. ### Claim 8 (depends on 6) The system of claim 6, wherein the predetermined current threshold is set via the serial peripheral interface. ### Claim 9 (depends on 6) The system of claim 6, wherein the predetermined threshold voltage is set via the serial peripheral interface. ### Claim 10 (depends on 5) The system of claim 5, further comprising an antenna coupled to the power amplifier. ### Claim 11 A method comprising: providing a first feedback signal for an amplifier connected to drive a load, the first feedback signal providing a signal having a magnitude dependent upon the load voltage when the load voltage falls below a predetermined voltage threshold; providing a second feedback signal for the amplifier, the second feedback signal having a magnitude dependent upon the current drawn to power the amplifier when the current drawn exceeds a predetermined current threshold; and adding either one of the first feedback signal and second feedback signal with a power dependent contribution signal and providing the combined signal as a hybrid feedback input to the amplifier. ### Claim 12 (depends on 11) The method of claim 11, wherein the predetermined current threshold and the predetermined voltage threshold is set via a serial peripheral interface. ### Claim 13 (depends on 12) The method of claim 12, wherein the predetermined current threshold and the predetermined voltage threshold is set using an automatic power controller. ### Claim 14 A method, comprising: sensing a dc current drawn by an amplifier configured to receive an input signal and deliver an output voltage to a load; sensing an output voltage delivered to the load by the amplifier; comparing the dc current drawn by the amplifier to a predetermined threshold current; comparing the output voltage to a predetermined minimum output voltage; providing a first feedback signal if the dc current exceeds the current threshold, the amplitude of the first feedback signal determined by the amount that the dc current exceeds the threshold current; providing a second feedback signal if the dc current is less than the current threshold and if the output voltage is less than a predetermined minimum output voltage, the magnitude of the second feedback signal determined by the amount that the predetermined minimum output voltage exceeds the output voltage; and adding either one of the first feedback signal and second feedback signal with a power dependent contribution signal; and generating a hybrid feedback input signal to the amplifier based on the power dependent contribution and either one of the first feedback signal and the second feedback signal. ### Claim 15 (depends on 14) The method of claim 14, wherein the predetermined current threshold and the predetermined voltage threshold is set via a serial peripheral interface. ### Claim 16 (depends on 15) The method of claim 15, wherein the predetermined current threshold and the predetermined voltage threshold is set using an automatic power controller.