Mixer second-order input-intercept point temperature compensation
AssigneeApple Inc.
InventorsLong Kong, Shinan Lu, Utku Seckin
Life of this patent
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Abstract
The present disclosure relates to compensating for temperature variation of a mixer. Embodiments herein may include performing a single-point Fast Fourier Transform (FFT) (or complex downconversion with DC average) for a number of samples to obtain a transform for each of the number of samples, phase aligning a set of phases associated with each transform, and averaging each transform to generate an analog-to-digital converter (ADC) power value. Further, the disclosed embodiments may include generating a compensation value based on the analog-to-digital converter power value and applying the compensation value to the calibration circuit of the mixer to compensate for a second-order intermodulation product.
Claims20
An electronic device, comprising:
- a receiver comprising a mixer and an analog-to-digital converter (ADC), the mixer comprising a calibration circuit;
- and
- one or more processors coupled to the receiver, the one or more processors configured to
- receive a first set of ADC power samples from the ADC,
- perform a first transform on the first set of ADC power samples associated with a first set of phases,
- receive a second set of ADC power samples from the ADC,
- perform a second transform on the second set of ADC power samples associated with a second set of phases, and
- apply a compensation value based on the first transform and the second transform to the calibration circuit of the mixer to compensate for a second-order intermodulation product.
A method comprising:
- receiving, via processing circuitry, a set of analog-to-digital converter (ADC) power samples at a mixer;
- receiving, via the processing circuitry, a set of phases associated with the set of ADC power samples;
- receiving, via the processing circuitry, a closest phasor based on a subharmonic of an ADC clock and the set of phases;
- and
- generating, via the processing circuitry, a compensation value based on the set of ADC power samples and the closest phasor;
- and
- applying, via the processing circuitry, the compensation value to a calibration circuit of the mixer.
One or more non-transitory, tangible, computer-readable media that store instructions configured to cause a processor to:
- receive a beat frequency of a second-order intermodulation product;
- receive a subharmonic of an analog-to-digital converter (ADC) clock that corresponds to the beat frequency;
- receive a first set of ADC power samples;
- perform a first transform on the first set of ADC power samples;
- receive a first set of phases associated with the first set of ADC power samples;
- receive a second set of ADC power samples;
- perform a second transform on the second set of ADC power samples;
- receive a second set of phases associated with the second set of ADC power samples;
- rotate the second transform to align the second set of phases and the first set of phases;
- and
- generate an ADC power value based on the first transform and the second transform as rotated.
Dependencies are inferred from the claim text.