Qualcomm Incorporated

Shahin Mehdizad Taleie

Dongwon Seo

Behnam Sedighi

Ashok Swaminathan

Nitz Saputra

Roberto Rimini

Bhushan Shanti Asuri

Udara Fernando

Honghao Ji

Parisa Mahmoudidaryan

Negar Rashidi

Shrenik Patel

Sang-June Park

Andrew Weil

Ibrahim Ramez Chamas

Tongyu Song

Xilin Liu

Chen Jiang

Ganesh Saripalli

Eunyung Sung

Gideon Shlomo Kutz

Igor Gutman

Gurkanwal Singh Sahota

Jong Hyeon Park

Peter J Shah

Chinmaya Mishra

Vinod Panikkath

Krishnaswamy Thiagarajan

Guoqing Miao

Ayush Mittal

Michael McGowan

Haibo Fei

Ronen Greenberger

Sameer Vasantlal Vora

Roy Benjamin Silverstein

Anant Gupta

Oren Matsrafi

Zhilong Tang

Liviu Chiaburu

Derui Kong

Jan Paul Van Der Wagt

Ping Wing Lai

Yossi Waldman

Jalal Ahmad Elhusseini

Tonmoy Biswas

Gerrit Groenewold

Jaswinder Singh

Siyu Yang

Sudharsan Kanagaraj

Yen-Wei Chang

Gal Keret

Sy-Chyuan Hwu

Mohammadhossein Naderi Alizadeh

Yang You

Ganesh Ramachandra Murthy Saripalli

Jenny Kuo

Methods and apparatus for sharing digital-to-analog (DAC) converters in a reconfigurable DAC circuit to support two or more transmit chains of a wireless transmitter configured for different radio access technologies (RATs) and/or different transmitter architectures. One example DAC circuit generally includes at least four DACs and a plurality of switches coupled to outputs of the at least four DACs such that the DAC circuit is configured as a multi-channel DAC circuit with at least four channels for a first set of one or more frequency bands and as an interleaved DAC circuit with at least two channels for a second set of one or more frequency bands different from the first set of frequency bands.

Reconfigurable transmit digital-to-analog converter (DAC) circuit

Certain aspects of the present disclosure provide a digital-to-analog converter (DAC) system. The DAC system generally includes a plurality of current steering cells, each comprising a current source coupled to at least two current steering switches, wherein control inputs of the at least two current steering switches are coupled to an input path of the DAC system. The DAC system may also include a current source toggle circuit configured to selectively disable the current source of at least one of the plurality of current steering cells, and a feedforward path coupled between the input path and at least one control input of the current source toggle circuit.

Digital amplitude tracking current steering digital-to-analog converter

Certain aspects of the present disclosure generally relate to circuitry and techniques for digital-to-analog conversion. One example device for digital-to-analog conversion generally includes: a digital-to-analog converter (DAC) having an input coupled to an input node of the device; a first return-to-zero (RZ) DAC having an input coupled to an input node of the device; and a combiner, wherein an output of the first DAC is coupled to a first input of the combiner, and wherein an output of the first RZ DAC is coupled to a second input of the combiner.

Return-to-zero (RZ) digital-to-analog converter (DAC) for image cancellation

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may receive a downlink control message from a base station indicating a modulation and coding scheme (MCS) associated with an uplink transmission, a number of layers associated with the uplink transmission, or both. The UE may determine to adjust (for example, reduce) a first number of bits based on the MCS, the number of layers, or both. The first number of bits may include an effective number of bits (ENOB) supported at a digital-to-analog converter (DAC) of the UE, a number of bits (NOB) supported at a transmission front end (TxFE) component of the UE, or both. The UE may transmit the uplink transmission to the base station according to the adjusted first number of bits.

Dynamic transmission front end and digital-to-analog converter in modem

Certain aspects of the present disclosure generally relate to circuitry and techniques for digital-to-analog conversion. For example, certain aspects provide an apparatus for digital-to-analog conversion. The apparatus generally includes a mixing-mode digital-to-analog converter (DAC), a duty cycle adjustment circuit having an input coupled to an input clock node and having an output coupled to a clock input of the mixing-mode DAC, and a current comparison circuit having inputs coupled to outputs of the mixing-mode DAC and having an output coupled to a control input of the duty cycle adjustment circuit.

Mismatch and timing correction technique for mixing-mode digital-to-analog converter (DAC)

A current digital-to-analog converter includes a binary current-generating section configured to generate a binary-weighted current based on a first set of control signals; a unary current-generating section configured to generate a unary-weighted current based on a second set of control signals; and a current combining circuit configured to add or subtract a reference current and a current generated by a current source of the unary current-generating section using the binary-weighted current.

Apparatus and method for measuring current source mismatches in current-steering DAC by re-using R2R network

An RF-DAC transmitter is provided that includes an in-phase channel, a quadrature-phase channel, a first intermediate-phase channel, and a second intermediate-phase channel. Each channel includes a pair of interleaved RF-DACs for producing a pair of interleaved RF signals and a subtractor.

Digital RF-DAC

Certain aspects of the present disclosure generally relate to circuitry and techniques for digital-to-analog conversion. One example system for digital-to-analog conversion generally includes a first digital-to-analog converter (DAC) having an input coupled to an input node of the system and a mixing-mode DAC having an input coupled to an input node of the system. The mixing-mode DAC may include a second DAC and a mixer, an output of the second DAC being coupled to an input of the mixer. The system may also include a combiner, wherein an output of the first DAC is coupled to a first input of the combiner, and wherein an output of the mixer is coupled to a second input of the combiner.

Digital-to-analog converter (DAC) with mixing-mode parallel path image attenuation

Certain aspects of the present disclosure generally relate to a programmable multi-mode digital-to-analog converter (DAC) for generating a frequency-modulated signal. For example, certain aspects provide a circuit for sweeping a frequency of an output signal. The circuit generally includes a DAC having an input coupled to an input path of the circuit and an output coupled to an output path of the circuit, a first mixer selectively incorporated in the input path coupled to the input of the DAC, and a second mixer selectively incorporated in the output path coupled to the output of the DAC.

Programmable multi-mode digital-to-analog converter (DAC) for wideband applications

An apparatus is disclosed for proximity detection using a hybrid-transceiver. In an example aspect, the apparatus includes a hybrid transceiver coupled to a first antenna and a second antenna. The hybrid transceiver is configured to generate, in a digital domain, a digital baseband radar signal. The hybrid transceiver is also configured to transmit, via the first antenna, a radio-frequency transmit signal that is derived from the digital baseband radar signal. Via the second antenna, the hybrid transceiver is configured to receive a radio-frequency receive signal, which includes a portion of the radio-frequency transmit signal that is reflected by an object. In an analog domain, the hybrid transceiver is configured to generate an analog receive signal that includes a beat frequency, which is indicative of a frequency offset between the radio-frequency transmit signal and the radio-frequency receive signal. The analog receive signal is derived from the radio-frequency receive signal.

Proximity detection using a hybrid transceiver

An interleaved digital-to-analog converter (DAC) system may include a first sub-DAC and a second sub-DAC and may be configured to provide both a converter output signal and a calibration output signal. The converter output signal may be provided by adding the first sub-DAC output signal and the second sub-DAC output signal. The calibration output signal may be provided by subtracting one of the first and second sub-DAC output signals from the other. The calibration output signal may be used as feedback to adjust the phase of one of the sub-DACs relative to the other, to promote phase matching their output signals.

Image calibration for time-interleaved digital-to-analog converter

A communication circuit may include a first pair of digital-to-analog converters (DACs) coupled to an input of a first mixer and configured to generate first baseband signals. The communication circuit may further include a second pair of DACs coupled to an input of a second mixer and configured to generate second baseband signals. The second baseband signals may be shifted in phase relative to the first baseband signals.

Communication circuit including a transmitter

In one embodiment, a method for converting an input digital signal into an analog signal is provided. The method comprises modulating the input digital signal into a modulated digital signal, and converting the modulated digital signal into the analog signal using a digital-to-analog converter (DAC). The modulation shapes quantization noise of the DAC to place a notch at a frequency within an out-of-bound frequency band to reduce the quantization noise within the out-of-bound frequency band.

Error-feedback digital-to-analog converter (DAC)

A method and apparatus for attenuating transmit digital to analog converter (DAC) spurs is provided. The method begins when a reference voltage is injected into an amplifier. Next, an output of the ground low drop-out regulator is measured and is them compared with the reference voltage. The output of the amplifier is then adjusted based on the results of the comparison. If the reference voltage is higher then the output of the ground low drop-out regulator the output of the amplifier is adjusted to ground. If the reference voltage is lower than the output of the ground low drop-out regulator then the output of the amplifier is adjusted to match the reference voltage.

Transmit digital to analog converter (DAC) spur attenuation

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San Diego, CA, United States of America

Shahin Mehdizad Taleie