Halliburton Energy Services, Inc.

Eta Devices, Inc.

Massachusetts Institute of Technology

Chartered Semiconductor Manufacturing Ltd (corporation)

Nanyang Technological University

Stmicroelectronics Asia Pacific Pte Limited

Wei Li

David J Perreault

Jing Jin

Glenn Andrew Wilson

Xiang Wu

Yevgeniy A Tkachenko

Chung Lung Chang

Yao Ge

Joel L Dawson

Sapna George

Ruijia Wang

Arthur Cheng

Chuan Seng Tan

Kwang Hong Lee

John Hoversten

Yung Tao Lin

Shuyu Bao

Nathaniel Jay T Salazar

Balaji Lakshminarayanan

P Anantha

Lin Zhang

A method includes positioning a downhole tool in a borehole formed in a subsurface formation, wherein the downhole tool comprises a plurality of calipers arranged around a circumference of the downhole tool. The method includes detecting, using the plurality of calipers, a plurality of standoff measurements at different rotation angles and determining a plurality of apparent diameters of the borehole for the different rotation angles of the downhole tool based on the plurality of standoff measurements and at least one of a radius and a diameter of the downhole tool. The method includes determining a probability function based on the plurality of apparent diameters and determining a shape of the borehole based on the probability function.

Determination of borehole shape using standoff measurements

A well tool can be used in a wellbore that can measure characteristics of an object in the wellbore. The well tool includes an ultrasonic transducer for generating an ultrasonic wave in a medium of the wellbore. The ultrasonic transducer includes a front layer, a rear layer, backing material coupled to the rear layer, and piezoelectric material coupled to the front layer and to the backing material. The rear layer can improve signal-to-noise ratio of the transducer in applications such as imaging and caliper applications.

Ultrasonic transducer with reduced backing reflection

A downhole tool is placed in a borehole of a subsurface formation. The downhole tool comprises a plurality of calipers arranged around a circumference of the downhole tool. A plurality of standoff measurements is received for different rotation angles of the downhole tool, wherein each standoff measurement is indicative of a distance between one of the plurality of calipers and a wall of the borehole. A plurality of apparent diameters of the borehole is determined for the different rotation angles of the downhole tool based on the plurality of standoff measurements and a radius of the downhole tool. A probability function is determined based on the plurality of apparent diameters and at least one of a semiminor axis, semimajor axis, and ellipticity of the borehole is identified based on the probability function.

Acoustic imaging tools and methods use refracted wave amplitudes to generate borehole images, thereby providing a method and tool that is highly sensitive to borehole discontinuities.

Borehole imaging using amplitudes of refracted acoustic waves

An integrated power supply and modulator system includes integrated power supply and modulator system includes three subsystems: a switched-capacitor voltage balancer stage; a magnetic regulation stage; and at least one output switching stage. In one embodiment, the integrated power supply and modulator system further includes startup circuitry, feedback/feedforward circuitry and control circuitry.

Integrated power supply and modulator for radio frequency power amplifiers

Various embodiments may provide an optical structure. The optical structure may include a substrate. The optical structure may also include a core layer configured to carry optical light. The core layer may include germanium. The optical structure may further include an intermediate layer separating the substrate and the core layer so that the substrate is isolated from the core layer. The intermediate layer may include one or more materials selected from a group consisting of III-V materials, dielectric materials, and chalcogenide materials. A width of the core layer may be smaller than a width of the intermediate layer. A refractive index of the core layer may be more than 4. A refractive index of the intermediate layer may be smaller than 3.6.

Optical structure and method of forming the same

A method of obtaining an equivalent tool model includes obtaining a set of known well data, in which the known well data includes sensor data measured by a logging tool and an actual dispersion response, and the logging tool has an actual tool size. The method also includes obtaining one or more well parameters from the known well data, and inputting the one or more well parameters and a model tool size into a rigid tool model. The method further includes obtaining an estimated dispersion response from the rigid tool model, and fitting the estimated dispersion response to the actual dispersion response by adjusting the model tool size.

Method of minimizing tool response for downhole logging operations

Described embodiments provide a radio frequency (RF) amplifier system having at least one amplifier. The at least one amplifier includes an RF input port, an RF output port and a drain bias port. At least one voltage modulator is coupled to the bias port of the least one amplifier to provide a bias voltage. The bias voltage is selected by switching among a plurality of discrete voltages. At least one filter circuit is coupled between the at least one voltage modulator and the at least one amplifier. The at least one filter circuit controls spectral components resultant from transitions in the bias voltage when switching among the plurality of discrete voltages. A controller dynamically adapts at least one setting of the at least one voltage modulator by using multi-pulse transitions when switching among the plurality of discrete voltages for a first operating condition of the RF amplifier.

Linearity and noise improvement for multilevel power amplifier systems using multi-pulse drain transitions

Described embodiments provide an integrated power supply and modulator system. The system includes a magnetic regulation stage, a switched-capacitor voltage balancer stage, and at least one output switching stage. The switched-capacitor voltage balancer stage is coupled to an output of the magnetic regulation stage, and maintains a substantially ratiometric set of voltages with respect to a reference potential. The magnetic regulation stage includes an inductor and at least two switches to selectively couple the inductor to two or more of (a) an input of the magnetic regulation stage, (b) a first voltage node of the switched-capacitor voltage balancer stage, and (c) a second voltage node of the switched-capacitor voltage balancer stage. The output switching stage selectively couples at least two voltages from the switched-capacitor voltage balancer stage to an output of the system in response to control signals. The system may include startup circuitry, feedback/feedforward circuitry, and control circuitry.

Embodiments of the present disclosure are directed to techniques for adjusting the amplitude of a digital audio signal in the frequency domain to control the perceived loudness of the audio signal at a desired level. In one embodiment, a method first adjusts the audio signal to a desired loudness level by applying an adaptive wideband gain and thereafter a multi-band compression is applied to further reduce a dynamic range of the audio signal, and noise analysis and temporal masking operations are also performed to provide a pleasant sound for a listener or listeners.

Adaptive loudness levelling method for digital audio signals in frequency domain

A voltage-step down rectifier topology suitable for integration on a die of an integrated circuit is described. In one embodiment, a switched capacitor rectifier is provided having an architecture such that an input voltage swing of the switched-capacitor rectifier is a factor N times an output voltage where N depends upon the number of stages such that the switched-capacitor rectifier can provide a &#x3c0;/(2N) step-down voltage conversion ratio between an input fundamental ac peak voltage to the output dc voltage. In one embodiment, the rectifier is used in dc-dc conversion. In one embodiment, the rectifier is used in ac power delivery to low-voltage electronics.

Apparatus for multi-level switched-capacitor rectification and DC-DC conversion

A trench transistor formation method for creating source and drain regions and source and drain extension regions having an idealized doping profile using a single dopant implantation step. In one embodiment, the present invention is comprised of a method which includes forming a trench having sidewalls and a bottom into a substrate. The present embodiment also recites forming sidewalls spacer regions along at least a portion of the sidewalls of the trench. Subsequently, the present embodiment forms a gate dielectric along at least a portion of the bottom of the trench, and deposits a gate metal within the trench. The present embodiment then subjects the substrate to an etching process such that the top surface of the substrate is lower than the top surface of the sidewall spacer regions formed along the sidewalls of the trench. The present embodiment then performs a single dopant implantation step which results in the formation of both the source and drain regions and the source and drain extension regions wherein the source and drain regions have an implantation depth which is greater than the implantation depth of the source and drain extension regions. Additionally, substantially no dopant is implanted within a channel region residing beneath the gate metal disposed within the trench. In so doing, an idealized dopant profile is achieved within the trench transistor using the single dopant implantation step.

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Singapore, Singapore

Wei Li