Silicon Laboratories Inc.

Lucent Technologies Inc.

At&t Bell Laboratories

Other

At+t Corp.

Analog Devices,inc.

Agere Systems Inc.

American Telephone & Telegraph Co., At&t Bell Laboratories

John M Khoury

Richard Beale

Rangakrishnan Srinivasan

Yan Zhou

Mustafa H Koroglu

Navin Harwalkar

Michael Johnson

Jinwen Xiao

Pavel Konecny

Francesco Barale

Praveen Vangala

Michael A Wu

Xiaodong Wang

Axel Thomsen

Alan Lee Westwick

Wentao Li

Clayton H Daigle

Arup Mukherji

Zhongda Wang

Sriharsha Vasadi

Shahram Tadayon

Mitch Reid

Aslamali A Rafi

Abdulkerim Coban

Javier Elenes

David S Trager

Michael Wu

Vitor Pereira

Alan F Hendrickson

Luigi Panseri

Li Gao

Eduardo Viegas

Jeffrey Alderson

Michael R May

Dan Bernard Kasha

Kadaba Lakshmikumar

Russell Croman

Dale Harvey Nelson

Junsong Li

David R Pehlke

Marty Lynn Pflum

Thomas Edward Voor

Lysander Lim

Paul Zavalney

Phillip Matthews

Angelo Rocco Mastrocola

Sherry Xiaohong Wu

Peter C Metz

Mitchell Reid

Pio Balmelli

James D Chlipala

Maurice J Tarsia

Tiago Marques

Euisoo Yoo

Thi-Hong-Ha Vuong

Venugopal Gopinathan

Christopher S Gregg

Vincent Leung

Reza Shariatdoust

Tandur L Viswanathan

Randall Russell Pratt

James M Trosino

Kareem A Ragab

Majid Barazande-Pour

Karma S Bhutia

Jomo Edwards

Vincent W Leung

Ali Eshraghi

Harley F Burger, Jr

A transmitter including a frequency synthesizer with a voltage-controlled oscillator that provides an oscillating signal, a programmable delay circuit that delays the oscillating signal to provide a delayed oscillating signal, a power amplifier that is configured to amplify the delayed oscillating signal for transmission sufficient to produce interference, and a delay controller that programs the delay circuit with a delay time that reduces interference caused by coupling from the power amplifier to the voltage-controlled oscillator. The delay circuit may be programmed to reduce control voltage change of the voltage-controlled oscillator as a function of delay change, and/or to reduce phase noise degradation at an output of the transmitter as a function of delay change. The delay may be adjusted based on detected operating temperature. A calibration value may be determined at a calibration frequency, in which a frequency offset may be determined based on a selected channel frequency.

System and method of mitigating interference caused by coupling from power amplifier to voltage-controlled oscillator

A low power wake on radio circuit detects if an RF signal is present on an input to the wake on radio circuit. An RF sense circuit supplies an RF sense signal indicating whether the RF signal is present on the input. The RF sense signal is used to incrementally turn on digital decode logic to determine if a radio transmission that is unique to the wake on radio circuit has been received. If the unique radio transmission have been received, the wake on radio circuit supplies a wakeup signal to the rest of the system.

Low power wake on radio

A system and method for accurately determining a distance between two network devices using a Channel Sounding application is disclosed. The network devices each guarantee a fixed phase relationship between the transmit circuit and the receive circuit. In one embodiment, this is achieved by disposing the divider outside the phase locked loop and using the output of the divider to create the clocks for both the transmit circuit and receive circuit. In another embodiment, one or more dividers are disposed outside the phase locked loop, each having a reset, such that they can be initialized to a predetermined state. Further, by utilizing a divider with a reset, the quadrature signal generator is guaranteed to output clocks for the transmit circuit and the receive circuit that have a constant phase relationship.

Synchronization of receiver and transmitter local oscillators for ranging applications

In at least one embodiment, a method for measuring a distance between a first communications device including a first local oscillator and a second communications device including a second local oscillator includes unwrapping N phase values to generate N unwrapped phase values. N is an integer greater than one. Each of the N phase values indicate an instantaneous phase of a received signal. The method includes averaging the N unwrapped phase values to generate an average phase value. The method includes wrapping the average phase value to generate a final phase measurement of the first local oscillator with respect to the second local oscillator.

Phase measurements for high accuracy distance measurements

A fractional-N phase-locked loop (PLL) that maintains phase coherence for an output signal with a plurality of possible output frequencies. The fractional-N PLL includes an oscillator, a phase detector to receive a reference clock signal and a feedback signal, and a multi-modulus divider coupled in a feedback path between the oscillator and the phase detector. A multi-modulus pattern generator supplies a drive pattern to the multi-modulus divider to achieve a desired change in frequency of the output signal. The multi-modulus pattern generator initiates the drive pattern at a boundary time to cause the output signal to have a substantially repeatable phase when restarting switching from any one of the output frequencies to any other of the output frequencies.

Maintaining phase coherence for a fractional-N PLL

A transmitter including a frequency synthesizer with a voltage-controlled oscillator that provides an oscillating signal, a programmable delay circuit that delays the oscillating signal to provide a delayed oscillating signal, a power amplifier that is configured to use the delayed oscillating signal for transmitting a signal, and a delay controller that programs the delay circuit with a delay time that reduces interference caused by coupling from the power amplifier to the voltage-controlled oscillator. The delay circuit may be programmed to reduce control voltage change of the voltage-controlled oscillator as a function of delay change, and/or to reduce phase noise degradation at an output of the transmitter as a function of delay change. The delay may be adjusted based on detected operating temperature. A calibration value may be determined at a calibration frequency, in which a frequency offset may be determined based on a selected channel frequency.

In one embodiment, an analog-to-digital converter includes: a sum circuit to receive an analog input signal and a feedback reference signal and generate a sum signal; a feedback circuit coupled to the sum circuit to provide the feedback reference signal to the sum circuit; a filter coupled to the sum circuit to receive the sum signal and generate a filtered signal; and a punctured quantizer coupled to the filter to receive the filtered signal and quantize the filtered signal to a digital output and to output the digital output and to provide the digital output to the feedback circuit.

Analog-to-digital converter having punctured quantizer

An apparatus includes a digitally controlled oscillator (DCO), which includes an inductor coupled in series with a first capacitor. The DCO further includes a second capacitor coupled in parallel with the series-coupled inductor and first capacitor, a first inverter coupled in parallel with the second capacitor, and a second inverter coupled back-to-back to the first inverter. The DCO further includes a digital-to-analog-converter (DAC) to vary a capacitance of the first capacitor.

Radio-frequency (RF) apparatus for digital frequency synthesizer including sigma-delta modulator and associated methods

Apparatus for digital frequency synthesizer with sigma-delta modulator and associated methods

A system and method for one-way ranging is disclosed. The system comprises a transmitter, also referred to as a tag, transmitting a first frequency in a first frequency group. The receiver, also referred to as the locator, receives the first frequency and measures the phase at a first point in time. At a later time, the transmitter switches to a second frequency, which is close in frequency to the first frequency so as to also be part of the first frequency group. The receiver also switches to the second frequency. The receiver then measures the phase of the second frequency at a second point in time. The transmitter and receiver then repeat this sequence for a second frequency group. The four phase measurements are used to determine the distance from the transmitter to the receiver. In this way, improved accuracy may be achieved by having a large separation between the first frequency group and the second frequency group.

One-way phase-based high accuracy distance measurement apparatus and algorithm

A method for communicating between a first radio frequency communications device including a first local oscillator and a second radio frequency communications device including a second local oscillator includes generating phase values based on samples of a received signal. Each of the phase values indicates an instantaneous phase of the received signal. The method includes unwrapping the phase values to generate unwrapped phase values. The method includes generating frequency offset estimates based on the unwrapped phase values. The method includes generating an average frequency offset estimate based on the unwrapped phase values. The method includes wrapping the average frequency offset estimate to generate a residual frequency offset estimate. The method includes adjusting the first local oscillator based on the residual frequency offset estimate, thereby reducing a frequency offset between the first local oscillator and the second local oscillator.

Correction of frequency offset between initiator and reflector

An apparatus includes a radio-frequency (RF) circuit, which includes a power amplifier coupled to receive an RF input signal and to provide an RF output signal in response to a modified bias signal. The RF circuit further includes a bias path circuit coupled to modify a bias signal as a function of a characteristic of an input signal to generate the modified bias signal. The bias path circuit provides the modified bias signal to the power amplifier.

Apparatus for radio-frequency amplifier with improved performance and associated methods

Apparatus for digitally controlled oscillators and associated methods

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Austin, TX, United States of America

John M Khoury