Apple Inc.

Omar E Elaasar

Aly Ismail

Gang Zhang

Shan He

Anandaroop Chakrabarti

An electronic device may include wireless circuitry having one or more differential circuits. A differential circuit can include first and second input transistors, first and second degeneration components, and first and second distortion cancellation transistors cross-coupled with the first and second input transistors. The first distortion cancellation transistor can be configured to sense a voltage at the first input transistor and to produce corresponding currents for cancelling a differential mode harmonic distortion current flowing through the second input transistor and for cancelling a common mode harmonic distortion current flowing through the first input transistor. The second distortion cancellation transistor can be configured to sense a voltage at the second input transistor and to produce corresponding currents for cancelling a differential mode harmonic distortion current flowing through the first input transistor and for cancelling a common mode harmonic distortion current flowing through the second input transistor.

Differential mode and common mode distortion cancellation circuitry

This disclosure is directed to a Voltage-Controlled Oscillator (VCO) with improved phase noise compared to other VCOs. The VCO may include a first cell and a second cell separated by common-mode (CM) isolation circuitry to reduce an amplitude of CM noise at an output signal. The CM isolation circuitry may inductively couple the first cell to the second cell for generating the output signal based on a resonant frequency range including resonant frequencies of the CM isolation circuitry, the first cell, and the second cell. As such, the first cell and the second cell may each include a portion of an entirety of the CM noise. In some cases, the portions of the CM noise on the first cell and/or the second cell may improve a signal to noise ratio of the output signal.

Inductor-capacitor voltage-controlled oscillator with common-mode noise separation

Mixer circuitry can include a first pair of transistors coupled to a first tail node and configured to receive a local oscillator signal, a second pair of transistors coupled to a second tail node and configured to receive the local oscillator signal, a first digital-to-analog converter, a second DAC coupled between the first DAC and of the first pair of transistors, and a third DAC coupled between the first DAC and the second pair of transistors. During a first phase, control circuitry can sweep the first DAC to trim a first and/or other odd order local oscillator feedthrough. During a second phase, the control circuitry can sweep the second DAC to trim a second and/or other even order local oscillator feedthrough. During a third phase, the control circuitry can sweep the second and third DACs to reject signals associated with a second harmonic conversion gain of the mixer circuitry.

Methods and circuitry for reducing mixer harmonics conversion gain and local oscillator fundamental and harmonics feedthrough

This disclosure is directed to a Voltage-Controlled Oscillator (VCO) with reduced phase noise compared to other VCOs. The VCO may include a first cell and a second cell separated by common-mode (CM) isolation circuitry. The first cell and the second cell may each include a portion of the CM noise of the VCO. Moreover, gate terminals of switches of the first cell and the second cell may be cross-coupled to drain terminals of the switches of the second cell and the first cell respectively. An interdependency of voltages of the first cell and the second cell may reduce an amplitude of the respective portions of the CM noise on the first cell and the second cell.

Inductor-capacitor voltage-controlled oscillator with common-mode noise suppression

An electronic device may include wireless circuitry having a mixer configured to receive an oscillating signal from oscillator circuitry. The oscillator circuitry can include a chain of buffer circuits sometimes referred to as oscillator driver circuitry. Transformers may be coupled at the input and output of each buffer circuit in the chain. Adjustable biasing circuits may be formed at the input of a selected buffer circuit in the chain of the buffer circuits. The adjustable biasing circuits can be digital-to-analog converters (DACs). The adjustable biasing circuits may be configured to apply a differential direct current (DC) offset voltage to the input of the selected buffer circuit. The differential DC offset voltage can have a value chosen to minimize a second harmonic component of the oscillator driver circuitry. Configured and operated in this way, a second harmonic conversion gain of the mixer can be reduced and can improve the transmit and receive performance of the wireless circuitry.

Growing community of inventors

San Diego, CA, United States of America

Omar E Elaasar