# US 12,771,400 B2 · Oscillator leakage calibration > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,771,400 B2 - Document ID: US12771400B2 - Status: Granted - Kind: B2 - Application number: 18/470,245 - Filed: 2023-09-19 - Published: 2025-03-20 - Granted: 2026-10-20 - Earliest claimed: 2023-09-19 - Assignees: QUALCOMM Incorporated - Applicants: Qualcomm Incorporated - Inventors: Waqas Ahmad; Chinmaya Mishra - Web page: https://patentgrep.com/patent/US12771400B2 ## CPC - H04B 1/525: with means for reducing leakage of transmitter signal into the receiver - H04B 1/0475: {with means for limiting noise, interference or distortion (H04B1/0483 takes precedence)} - H04B 17/11: for calibration - H04B: TRANSMISSION ## Abstract An apparatus is disclosed for oscillator leakage calibration. The apparatus includes a mixer circuit and calibration circuitry. The mixer circuit has a first stage including at least one transistor coupled between a mixer input and a mixer output and a second stage including one or more transistors coupled between the at least one transistor and the mixer output. The mixer circuit also has tuning circuitry coupled to the at least one transistor. The calibration circuitry includes at least one resistor coupled between a power distribution node and at least one mixer node, with the at least one mixer node coupled between the at least one transistor and the one or more transistors, and at least one switch coupled between the power distribution node and the at least one mixer node. The calibration circuitry also includes controller circuitry coupled between the mixer node and the tuning circuitry. ## Claims ### Claim 1 An apparatus comprising: a mixer circuit comprising: a first stage comprising at least one transistor coupled between a mixer input and a mixer output; a second stage comprising one or more transistors coupled between the at least one transistor of the first stage and the mixer output, the one or more transistors coupled between a local oscillator signal input and the mixer output; and tuning circuitry coupled to the at least one transistor of the first stage; and calibration circuitry comprising: at least one resistor coupled between a power distribution node and at least one mixer node, the at least one mixer node coupled between the at least one transistor of the first stage and the one or more transistors of the second stage; at least one switch coupled between the power distribution node and the at least one mixer node; and controller circuitry coupled between the at least one mixer node and the tuning circuitry, wherein the controller circuitry comprises a comparator having a first input and a second input, wherein the first input of the comparator is coupled to the at least one mixer node and the second input of the comparator is coupled to a node configured to provide a reference voltage. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein: the at least one switch is coupled in series with the at least one resistor between the power distribution node and the at least one mixer node; and the at least one switch is coupled between the at least one resistor and the at least one mixer node. ### Claim 3 (depends on 2) The apparatus of claim 2, wherein: the controller circuitry is coupled between the tuning circuitry and another node that is coupled between the at least one switch and the at least one resistor. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein: the comparator has an output coupled to the tuning circuitry; and the controller circuitry is configured to: provide a control signal to the tuning circuitry; and adjust the control signal based on the reference voltage at the second input of the comparator and a voltage present at the first input of the comparator. ### Claim 5 (depends on 4) The apparatus of claim 4, wherein: the controller circuitry is configured to adjust the control signal until the voltage present at the first input of the comparator is substantially equal to the reference voltage at the second input of the comparator; and the voltage present at the first input of the comparator represents a current flowing through the at least one transistor of the first stage of the mixer circuit. ### Claim 6 (depends on 4) The apparatus of claim 4, wherein: the tuning circuitry comprises at least one bias voltage generator; the at least one bias voltage generator is configured to apply at least one bias voltage to at least one gate of the at least one transistor of the first stage of the mixer circuit; and the controller circuitry is configured to adjust the control signal to change the at least one bias voltage applied by the at least one bias voltage generator to the at least one gate of the at least one transistor of the first stage of the mixer circuit. ### Claim 7 (depends on 6) The apparatus of claim 6, wherein: the at least one transistor of the first stage of the mixer circuit comprises a plus transistor and a minus transistor of the first stage of the mixer circuit; the at least one bias voltage comprises a plus bias voltage and a minus bias voltage; the controller circuitry is configured to adjust the control signal to change the plus bias voltage based on a plus current flowing through the plus transistor; and the controller circuitry is configured to adjust the control signal to change the minus bias voltage based on a minus current flowing through the minus transistor. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein: the at least one resistor comprises a plus resistor and a minus resistor. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein: the at least one transistor of the first stage of the mixer circuit comprises a plus transistor and a minus transistor; and the controller circuitry is configured to: measure a plus voltage corresponding to the plus resistor and the plus transistor and a minus voltage corresponding to the minus resistor and the minus transistor; provide a control signal to the tuning circuitry; and adjust the control signal based on the plus voltage and the minus voltage. ### Claim 10 (depends on 9) The apparatus of claim 9, wherein: the plus voltage represents a plus current flowing through the plus transistor of the first stage of the mixer circuit, and the minus voltage represents a minus current flowing through the minus transistor of the first stage of the mixer circuit; and the controller circuitry is configured to adjust the control signal to reduce a difference between the plus voltage and the minus voltage. ### Claim 11 (depends on 8) The apparatus of claim 8, wherein: the controller circuitry comprises at least one analog-to-digital converter having at least one input, the at least one input of the analog-to-digital converter coupled to the plus resistor and the minus resistor. ### Claim 12 (depends on 1) The apparatus of claim 1, wherein: the tuning circuitry comprises at least one bias voltage generator; the at least one transistor of the first stage comprises a gate terminal; and the at least one bias voltage generator of the tuning circuitry is coupled to the gate terminal of the at least one transistor of the first stage. ### Claim 13 (depends on 12) The apparatus of claim 12, wherein: the gate terminal of the at least one transistor of the first stage comprises a front-gate terminal. ### Claim 14 (depends on 12) The apparatus of claim 12, wherein: the gate terminal of the at least one transistor of the first stage comprises a back-gate terminal. ### Claim 15 (depends on 1) The apparatus of claim 1, wherein: the tuning circuitry comprises at least one bias voltage generator, the at least one bias voltage generator comprising: one or more current sources coupled between first and second power distribution nodes; and one or more resistors coupled in series with the one or more current sources between the first and second power distribution nodes. ### Claim 16 (depends on 15) The apparatus of claim 15, wherein the one or more current sources comprise at least one adjustable current source. ### Claim 17 (depends on 15) The apparatus of claim 15, wherein the one or more resistors comprise at least one adjustable resistor. ### Claim 18 (depends on 1) The apparatus of claim 1, wherein: the at least one transistor of the first stage comprises a plus first transistor and a minus first transistor; the one or more transistors of the second stage comprise a plus second transistor and a minus second transistor; the at least one mixer node comprises a plus mixer node and a minus mixer node, the plus mixer node coupled between the plus first transistor and the plus second transistor, the minus mixer node coupled between the minus first transistor and the minus second transistor; and the at least one switch comprises a plus switch and a minus switch, the plus switch coupled in series with the at least one resistor between the power distribution node and the plus mixer node, the minus switch coupled in series with the at least one resistor between the power distribution node and the minus mixer node. ### Claim 19 (depends on 1) The apparatus of claim 1, further comprising: a wireless interface device comprising the mixer circuit and the calibration circuitry; a display screen; and at least one processor operatively coupled to the display screen and at least a portion of the wireless interface device, the at least one processor configured to present one or more graphical images on the display screen based on one or more wireless signals communicated using the mixer circuit of the wireless interface device. ### Claim 20 An apparatus comprising: a mixer circuit comprising: a first stage comprising at least one transistor coupled between a mixer input and a mixer output; a second stage comprising one or more transistors coupled between the at least one transistor of the first stage and the mixer output; and tuning circuitry coupled to the at least one transistor of the first stage; and calibration circuitry comprising: at least one resistor coupled between a power distribution node and at least one mixer node, the at least one mixer node coupled between the at least one transistor of the first stage and the one or more transistors of the second stage; at least one switch coupled in series with the at least one resistor between the power distribution node and the at least one mixer node; and controller circuitry coupled between the at least one mixer node and the tuning circuitry, wherein the tuning circuitry comprises at least one bias voltage generator, the at least one transistor of the first stage comprises a gate terminal, and the at least one bias voltage generator of the tuning circuitry is coupled to the gate terminal of the at least one transistor of the first stage. ### Claim 21 An apparatus comprising: a mixer circuit comprising: a first stage comprising at least one transistor coupled between a mixer input and a mixer output; a second stage comprising one or more transistors coupled between the at least one transistor of the first stage and the mixer output, the one or more transistors coupled between a local oscillator signal input and the mixer output; and tuning circuitry coupled to the at least one transistor of the first stage; and calibration circuitry comprising: at least one resistor coupled between a power distribution node and at least one mixer node, the at least one mixer node coupled between the at least one transistor of the first stage and the one or more transistors of the second stage; at least one switch coupled between the power distribution node and the at least one mixer node; and controller circuitry coupled between the at least one mixer node and the tuning circuitry, wherein the at least one transistor of the first stage comprises a plus first transistor and a minus first transistor; wherein the one or more transistors of the second stage comprise a plus second transistor and a minus second transistor; wherein the at least one mixer node comprises a plus mixer node and a minus mixer node, the plus mixer node coupled between the plus first transistor and the plus second transistor, the minus mixer node coupled between the minus first transistor and the minus second transistor; and wherein the at least one switch comprises a plus switch and a minus switch, the plus switch coupled in series with the at least one resistor between the power distribution node and the plus mixer node, the minus switch coupled in series with the at least one resistor between the power distribution node and the minus mixer node.