Cirrus Logic Inc.

Arizona State University

Jing Bai

Xiaofan Fei

Xin Zhao

Lei Zhu

Tejasvi Das

Yu Yao

Chao Wang

John L Melanson

Anindya Bhattacharya

Wai-Shun Shum

Alan Mark Morton

Ali Basiri

Tim Green

Xiahui Chen

Chu Wang

Ku He

Amar Vellanki

Julius Yellowhair

Miao Song

Jiawei Zuo

A method of fabricating a polarization sensor is described. It includes a quarter-wave plate to convert circularly polarized light into linearly polarized light. The quarter-wave plate is realized as a metasurface. The sensor also includes a linear polarizer to analyze the light generated by the quarter wave plate, and a photodetector to receive the analyzed light. The sensor may be combined with other linear polarization sensors to form a sensor capable of complete measurement of the polarization state of incident light.

On-chip polarization detection and polarimetric imaging

Provided herein are systems and related methods of performing solar field and receiver inspections based on polarimetric-enhanced imaging.

Autonomous solar field and receiver inspections based on polarimetric-enhanced imaging

An amplification system with an output driver stage for providing an output signal to acoustic output transducers such as speakers or haptic output devices removes signal distortion caused by output stage non-linearities by pre-distorting an input signal. The system includes the output driver stage, an input stage for receiving the input signal, and a processing block that receives the input signal and provides an output signal to the output driver stage. The processing block includes a pre-distortion circuit that applies a pre-distortion function to the input signal to generate the output signal if a signal level of the input signal is greater than a threshold amplitude, and if the signal level is less than or equal to the threshold amplitude, generates the output signal from the input signal by bypassing the pre-distortion circuit.

Signal amplitude-selected signal predistortion in an amplifier

A circular polarization filter of a chiral metasurface structure is disclosed including a substrate having a nanograting pattern extending from the substrate, a dielectric layer formed directly on the nanograting pattern, and a plasmonic structure in direct contact with the dielectric layer, where the plasmonic structure may be oriented at a nonzero angle with respect to the nanograting pattern. An integrated polarization filter array is also disclosed including include a linear polarization filter, and a circular polarization filter. Methods of detecting full-stokes polarization using an integrated polarization filter array having both linear and circular polarization filters made from chiral metasurface structures is disclosed. Methods of using a Mueller matrix to evaluate polarization response of any optical device or system is also disclosed.

Polarization filters having nanograting pattern and plasmonic structure oriented at nonzero angle

A polarization sensor is described. It includes a quarter-wave plate to convert circularly polarized light into linearly polarized light. The quarter-wave plate is realized as a metasurface. The sensor also includes a linear polarizer to analyze the light generated by the quarter-wave plate, and a photodetector to receive the analyzed light. The sensor may be combined with other linear polarization sensors to form a sensor capable of complete measurement of the polarization state of incident light. An array of these sensors can be integrated directly onto image sensors to form a polarimetric imager.

A driver system may include a first n-type field-effect transistor coupled at its non-gate terminals between an output of the driver system and a first terminal of a supply voltage and configured to drive the output when the first n-type field-effect transistor is activated, a second n-type field-effect transistor coupled at its non-gate terminals between an output of the driver system and a second terminal of the supply voltage and configured to drive the output when the second n-type field-effect transistor is activated, a high-side capacitor coupled to the output of the driver system, and a low-side capacitor coupled to the second terminal of the supply voltage, wherein the high-side capacitor and the low-side capacitor are configured to track and correct for mismatches between a first resistance of the first n-type field-effect transistor and a second resistance of the second n-type field-effect transistor.

Dual bootstrapping for an open-loop pulse width modulation driver

A system may include a digital modulator configured to modulate an input signal received at an input of the digital modulator to generate a modulated input signal at an output of the digital modulator, a digital gain element having a digital gain and coupled to the digital modulator, an open-loop Class-D amplifier coupled to an output of the digital modulator and configured to amplify the modulated input signal, wherein the open-loop Class-D amplifier is powered from a variable power supply having a variable supply voltage which is variable in response to one or more characteristics of the input signal, and a control circuit configured to control the digital gain to approximately cancel changes in an analog gain of the open-loop Class-D amplifier due to variation in the variable supply voltage in response to the one or more characteristics of the input signal.

Gain control in a class-D open-loop amplifier

An apparatus detects a short of a class-D amplifier. A pulse detector detects an output PWM pulse exceeds a predetermined width and a controller differentiates whether the pulse width exceeding is caused by a short or by a large digital input signal occurring during normal operation based on an expected level of the digital input signal to a level of the digital input signal when the pulse width exceeds the predetermined width. The expected level is dynamically obtained in response to one or more previous PWM pulses exceeding the predetermined width during the normal operation and may be selected based on an amount the pulse exceeds the predetermined width. A lookup table of predetermined levels, selected based on impedance of a load, provides the expected level if the expected level has not yet been dynamically obtained when the pulse width exceeds.

Digital short detection method of class D amplifier

A signal processing system may include a modulation stage configured to generate a modulated input signal, an open-loop switched mode driver coupled to the modulation stage and configured to generate an output signal from the modulated input signal, a voltage regulator configured to generate a supply voltage that supplies electrical energy to the open-loop switched mode driver, and a control subsystem configured to, when a magnitude of the modulated input signal falls below a threshold magnitude, control the voltage regulator to control the supply voltage such that the output signal varies non-linearly with the modulated input signal for magnitudes of the modulated input signal below the threshold magnitude.

Open-loop class-D amplifier system with analog supply ramping

A peak junction temperature monitoring system for a semiconductor device includes a peak power dissipation sensor for sensing the peak power dissipation in the device. A temperature sensor senses an average temperature of the device, and a peak junction temperature computation circuit generates a signal representative of a peak junction temperature based on input from the peak power dissipation sensor and the temperature sensor.

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Tempe, AZ, United States of America

Jing Bai