Marvell International Limited

Other

Shuran Wei

Lawrence Tse

Xiaodong Jin

George Chien

King Chun Tsai

Sehat Sutardja

Runsheng He

Xiaopeng Chen

Randy Tsang

A compensator generating a compensation signal to compensate for nonlinear echo in an output of a current source. The nonlinear echo is a result of transitioning the current source between an ON state and an OFF state. The compensator includes driving, weighting, function, and compensating circuits. The driving circuit receives a first signal that is based on the output of the current source. The weighting circuit is configured to generate a second signal based on weighted versions of the first signal. The function circuit, based on the second signal, (i) updates each of multiple functions, and (ii) selects a first function. The driving circuit generates a driving signal based on the first function selected by the function circuit. The compensating circuit generates the compensation signal based on the driving signal to compensate for the nonlinear echo provided by the output of the current source.

Method and apparatus to compensate for nonlinear echo in an output of a current source

A nonlinear echo compensator comprises a mapping circuit that includes a weighting circuit that generates a weighted signal based on a current symbol and a prior symbol and a function generating circuit that selects one of N functions based on the weighted signal, where N is an integer greater than one. The mapping circuit generates a driving signal based on the selected one of the N functions and the weighted signal. A canceling circuit generates a nonlinear echo compensation signal based on the driving signal.

Nonlinear echo compensator for class B transmitter line driver

A transmitter system includes a transmitter with a power amplifier. An antenna communicates with the power amplifier. A protection circuit generates a sensed signal that varies with an impedance of the antenna and reduces an output of the power amplifier in response to the sensed signal exceeding a predetermined threshold.

Protection circuit and method for RF power amplifiers in WLAN transceivers

A low-noise amplifier comprises a first amplification circuit that includes a control terminal and a first terminal. An impedance load communicates with the first terminal. A feedback circuit outputs an output current to the first terminal and that generates a bias current, which is output to the control terminal and is based on a difference between the output current and N times a reference current, where N is greater than zero.

Active bias circuit for low-noise amplifiers

A protection circuit for a power amplifier of a radio frequency transmitter includes a sensing circuit that generates a sensed signal based on an output of the power amplifier. A reference signal generator generates a reference signal. A comparator communicates with the sensing circuit and the reference signal generator and outputs a first state when the reference signal exceeds the sensed signal and a second state when the sensed signal exceeds the reference signal. A turn off circuit turns off the power amplifier when the comparator is in the second state.

A nonlinear echo compensator compensates for nonlinear echo in a transceiver including a transmitter line driver with current cells that are operated in a Class B operating mode. A mapping circuit generates a pattern dependent driving signal. A coefficient generator generates a compensator coefficient. A canceling circuit communicates with the mapping circuit and the coefficient generator and compensates for nonlinear echo in a received signal based on the pattern dependent driving signal and the compensator coefficient.

A low-noise amplifier with a first amplification circuit that includes a control terminal, a first terminal, and a second terminal that communicates with a first reference voltage. An impedance load that communicates with the first terminal and a feedback circuit that comprises a current source that communicates with a second reference voltage. A comparator circuit that includes a first input, a second input and an output that communicates with the control terminal. A first impedance that communicates with the current source and the first input and that generates a predetermined reference voltage based on a reference current generated by the current source and a second impedance that communicates with the second input and the impedance load wherein the feedback circuit compares a voltage, based on an output current associated with the first terminal, with the reference voltage to generate a bias signal that is applied to the control terminal.

A local transmitter power control system for a radio frequency transmitter of a wireless local area network device includes a transmitter that transmits RF signals. A sensor detects at least one of amplitude and power of said RF signals and generates a sensed signal. The gain adjuster includes a comparator that receives an amplitude signal and/or a power signal detected by the sensor. The comparator compares the amplitude and/or power to the threshold signal. The gain of the transmitter is adjusted accordingly.

Local transmitter output power control system for wireless applications

A low-noise amplifier includes a first amplification device. The first amplification device includes a control terminal, a first terminal, and a second terminal. The low-noise amplifier also includes a feedback circuit in communication with the control terminal and the first terminal. The feedback circuit compares a voltage, corresponding to an output current associated with the first terminal, with a predetermined reference voltage to generate a bias signal applied to the control terminal for biasing the low-noise amplifier.

A circuit that eliminates an off-chip inductive component connected between an integrated circuit (IC) arranged on a package and an external load comprises a package and an IC that is arranged on the package. A first bondwire arranged on the package has one end that communicates with the external load and an opposite end that communicates with the IC. A second bondwire located on the package has one end that communicates with the external load and an opposite end that communicates with the IC.

Methods and apparatus for improving high frequency input/output performance

An impedance matching circuit is provided for an IC arranged on a package that matches an impedance of an external load. The circuit includes a package, an IC that is arranged on the package, and an impedance matching circuit. The impedance matching circuit includes a first bondwire arranged on the package that has one end that communicates with the external load and an opposite end that communicates with said IC, a capacitance element arranged on the IC, and a second bondwire arranged on the package that has one end that communicates with the external load and an opposite end that communicates with one end of said capacitance element.

An input circuit for an integrated circuit (IC), which is mounted on a package having an input pin, rejects signal energy at a first frequency. A first bondwire arranged on the package has one end that communicates with the pin and an opposite end that communicates with components of the IC. A second bondwire located on the package has one end that communicates with the pin and an opposite end that communicates with a capacitance. The capacitance and an inductance of the first and second bondwires resonate at the first frequency to reject signal energy at the first frequency. Bondwires are also used to eliminate external components such as resonant components and impedance matching circuits to reduce cost.

Protection circuit and method for RF power amplifiers in WLAN tranceivers

A phase locked loop including a loop filter to generate a control voltage as a function of an input signal and a. reference voltage. A voltage controlled oscillator (VCO) coupled to the loop filter, includes a varactor having terminals. In response to the control voltage, the VCO generates a periodic output signal having a frequency that is a function of the varactor and the control voltage. The VCO duplicates noise appearing on one of the varactor terminals to another of the varactor terminals so that noise in the periodic output signal is reduced.

Growing community of inventors

San Jose, CA, United States of America

Shuran Wei