# US 10,763,913 B1 · Linear-in-dB log-amp with calibration for power detection > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,763,913 B1 - Document ID: US10763913B1 - Status: Granted - Kind: B1 - Application number: 16/372,698 - Filed: 2019-04-02 - Granted: 2020-09-01 - Earliest claimed: 2019-04-02 - Assignees: Integrated Device Technology, Inc. - Applicants: Integrated Device Technology, Inc. - Inventors: Himanshu Khatri; Samet Zihir; Tumay Kanar - Web page: https://patentgrep.com/patent/US10763913B1 ## CPC - H03F 3/245: {with semiconductor devices only} - H04B 1/44: Transmit/receive switching - H03F 3/04: with semiconductor devices only - H03F 3/19: with semiconductor devices only - H03G 3/3036: {in high-frequency amplifiers or in frequency-changers (H03G3/3052, H03G3/32, H03G3/34 take precedence)} - H04B 1/04: Circuits - H04B 1/18: Input circuits, e.g. for coupling to an antenna or a transmission line (coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H) - H03F 2200/105: A non-specified detector of the power of a signal being used in an amplifying circuit - H03F 2200/294: the amplifier being a low noise amplifier [LNA] - H03F 2200/451: the amplifier being a radio frequency amplifier - H03F: AMPLIFIERS - H04B: TRANSMISSION - H03G: CONTROL OF AMPLIFICATION ## Abstract An apparatus includes a log amplifier and a calibration circuit. The log amplifier may be configured to generate an output signal in response to an offset between a first voltage and a second voltage. The calibration circuit may be configured to disconnect an input power and perform a cancellation of the offset when the input power is not present. The first voltage may be generated by the apparatus in response to a power detection. The second voltage may be received from a reference circuit. The cancellation of the offset may extend a working range of the apparatus. The output may provide a linear-in-dB power detection. ## Claims ### Claim 1 An apparatus comprising: a log amplifier circuit configured to generate an output signal in response to an offset between a first voltage and a second voltage; and a calibration circuit configured to (i) disconnect an input power and (ii) perform a cancellation of said offset when said input power is not present, wherein (a) said first voltage is generated by said apparatus in response to a power detection, (b) said second voltage is received from a reference circuit, (c) said cancellation of said offset extends a working range of said apparatus, (d) said output signal provides a linear-in-dB power detection, (e) said calibration circuit comprises a comparison circuit configured to determine a difference between said first voltage and said second voltage when said input power is not present, (f) said difference is used to control one or more programmable current sources, and (g) said cancellation is performed by adjusting said programmable current sources in response to said difference. ### Claim 2 (depends on 1) The apparatus according to claim 1, wherein said log amplifier circuit is configured to enable a log correction in an analog domain. ### Claim 3 (depends on 1) The apparatus according to claim 1, wherein said working range is extended by setting said first voltage slightly lower than said second voltage. ### Claim 4 (depends on 1) The apparatus according to claim 1, wherein said calibration circuit is configured to disconnect said input power and perform said cancellation in an open loop configuration. ### Claim 5 (depends on 4) The apparatus according to claim 4, wherein said calibration circuit enables said open loop configuration by closing a first switch to disconnect said input power and opening a second switch to disable an amplifier. ### Claim 6 (depends on 1) The apparatus according to claim 1, wherein said cancellation is performed by an open-loop mechanism. ### Claim 7 (depends on 1) The apparatus according to claim 1, wherein said cancellation is performed by a closed-loop mechanism. ### Claim 8 (depends on 1) The apparatus according to claim 1, wherein said cancellation reduces said offset or eliminates said offset. ### Claim 9 (depends on 1) The apparatus according to claim 1, wherein (i) said apparatus is configured to generate said linear-in-dB power detection in a closed loop configuration and (ii) perform a calibration of said offset in an open loop configuration. ### Claim 10 (depends on 1) The apparatus according to claim 1, wherein (i) said linear-in-dB power detection is provided to a controller circuit and (ii) said controller circuit is configured to adjust a power level of a transceiver circuit in response to said linear-in-dB power detection. ### Claim 11 (depends on 1) The apparatus according to claim 1, wherein (i) said difference is used to control a first current source for said first voltage and a second current source for said second voltage, (ii) said first current source and said second current source are implemented using FET transistors in a P-channel configuration and (iii) said cancellation is performed by adjusting a strength of said first current source and said second current source in response to said difference. ### Claim 12 (depends on 1) The apparatus according to claim 1, wherein (i) said difference is used to control a first current of a first input device and a second current of a second input device, (ii) said first input device and said second input device are implemented using transistors in a NPN configuration and (iii) said cancellation is performed by adjusting a strength of said first current and said second current in response to said difference. ### Claim 13 (depends on 1) The apparatus according to claim 1, wherein (i) said difference is used to control a first bias voltage of a first current source and a second bias voltage of a second current source and (ii) said cancellation is performed by adjusting said first bias voltage and said second bias voltage in response to said difference. ### Claim 14 (depends on 1) The apparatus according to claim 1, wherein said working range of said apparatus is extended by approximately 5 dB to 10 dB. ### Claim 15 (depends on 1) The apparatus according to claim 1, wherein said calibration circuit disconnects said input power in response to an input from a controller. ### Claim 16 (depends on 15) The apparatus according to claim 15, wherein said controller provides said input at a startup time of a phased array antenna panel. ### Claim 17 (depends on 1) The apparatus according to claim 1, configured to implement a linear-in-dB log-amp with calibration for power detection.