Silicon Wave, Inc.

Conexant Systems, Inc.

Jorge Alberto Grilo

Bo Zhang

Ricke Waylan Clark

Ian Galton

Andrew Xavier Estrada

Mark Vernon Lane

Terrance Raymond Bourk

Christopher Dennis Hull

Stephen J Brown

Patrick Joseph Murphy

Kevin Jia-Nong Wang

Steven R Norsworthy

A novel mismatched-shaping DAC architecture is described. The inventive DAC partially spectrally shapes data conversion errors. In accordance with the present invention, the DAC mismatch-shaping function is fully effective for input signal amplitude levels that are relatively low (i.e., close to mid-scale), however, the mismatch-shaping function is not fully effective for input signal amplitude levels that are relatively high. This results in the simplification in complexity, reduced power dissipation, and shortened propagation delays associated with the mismatch-shaping DAC digital logic circuitry. Exemplary delta-sigma ADC and DAC architectures adapted for use with the present inventive partial mismatch-shaping DAC are also described.

Partial mismatch-shaping digital-to-analog converter

An apparatus for receiving signals includes a low noise amplifier (LNA) configured to receive a radio frequency (RF) signal. An I/Q direct down converter is coupled to the LNA. The I/Q direct down converter is configured to split the RF signal into real and imaginary components and to down convert the real and imaginary components directly to baseband signals. A local oscillator (LO) is coupled to the I/Q direct down converter and is configured to drive the I/Q direct down converter. First and second filters are coupled to the I/Q direct down converter. The first and second filters are configured to filter the down converted real and imaginary components, respectively. First and second analog-to-digital converters (ADCs) are coupled to the first and second filters, respectively. The first and second ADCs are configured to convert the real and imaginary components into digital signals. The first and second ADCs have a dynamic range that is wide enough to convert the filtered, down converted real and imaginary components to digital signals without using variable gain on the filtered and down converted real and imaginary components. An apparatus for use in wireless communications includes a radio, a modem and a controller integrated onto a single integrated circuit (IC). The radio includes a receiver for receiving data and a transmitter for transmitting data. The modem is coupled to the radio and is configured to demodulate received data and modulate data for transmission. The controller is coupled to the modem and includes a digital interface for external communications through which received data and data for transmission is sent, a connection state machine configured to accept commands through the digital interface and to respond to the commands by initiating a sequence, and a receive/transmit state machine configured to perform state control of the radio in response to the initiated sequence.

Apparatus and method for wireless communications

The invention provides a unique apparatus and method which varies the capacitance coupled to a circuit. In one embodiment, the variable capacitance comprises a unique variable capacitance array with multiple capacitance modules which can be selectively enabled. Each capacitance module has a capacitive value and a corresponding parasitic capacitance. The invention provides high linearity, low spread, improves the response to power fluctuations by maintaining a consistent relationship between the capacitive value and the parasitic capacitance in each capacitance module. For example, the invention can be used with devices to provide a linear variation of capacitance. In addition, the invention can be used to calibrate a wide range of devices.

High-linearity, low-spread variable capacitance array

Growing community of inventors

Foothill Ranch, CA, United States of America

Jorge Alberto Grilo