Gm Global Technolgoy Operations, Inc.

The Boeing Company

Hrl Laboratories, LLC

Other

Cynthia D Baringer

James Chingwei Li

Timothy J Talty

Mohiuddin Ahmed

Yen-Cheng Kuan

Zhiwei A Xu

Peter Petre

Albert E Cosand

Emilio A Sovero

Hsuanyu Pan

Jongchan Kang

Donald A Hitko

Andrew J MacDonald

Hasan Sharifi

Rahul Shringarpure

A method and apparatus for dynamically modifying filter characteristics of a Delta-Sigma modulator to accommodate for Doppler shift. A transceiver in a wireless cellular communication system for adapt to changes in the RF carrier frequency for maintaining signal integrity by applying a pilot tone in calibration to determine a frequency shift response for a bandpass filter. During operation, the system is operative to determine a Doppler shift and to shift the bandpass filter in response.

Dynamic frequency correction in delta-sigma based software defined receiver

A Delta-Sigma modulator architecture is disclosed that uses interleaving and dynamic matching algorithms to address the needs of multi-mode, multi-band high bandwidth transmitters. The proposed architecture also supports a novel software defined transmitter architecture based on an interleaved Delta-Sigma modulator to generate RF signals. The proposed architecture leverages interleaving concepts to relax subcomponent clock rates without changing the effective oversampling ratio, thus, making it easier to reach aggressive dynamic range goals across wider bandwidths at higher frequencies. The DEM algorithm helps to randomize mismatch errors across all interleaved paths and improves substantially the signal-to-noise ratio. Additionally, a tunable bandpass filter can be added to reject out-of-band emissions.

Interleaved sigma delta modulator based SDR transmitter

A apparatus for dynamically modifying filter characteristics of a delta-sigma modulator in order to receive and transmit radio frequency signals over a wide frequency range. The system is used for wide bandwidth radio system designed to adapt to various global radio standards and, more particularly, to a cellular radio architecture that employs a combination of a single circulator, programmable band-pass sampling radio frequency (RF) front-end and optimized digital baseband that is capable of supporting all current cellular wireless access protocol frequency bands.

Apparatus for multi carrier aggregation in a software defined radio

A single-chip tunable bandpass filter is provided having a bandpass filter circuit with all tuning components for the bandpass filter circuit formed on the single-chip to provide a programmed center frequency for the tunable bandpass filter. The bandpass filter circuit may include, but is not limited to, a plurality of serially coupled singe stage biquad filter circuits coupled to an input formed on the single-chip and configured to provide a bandpass filtered output signal to an output formed on the single-chip. The bandpass filtered output may be provided by an output buffer formed on the single-chip. The single-chip includes at least one tuning input to receive data for tuning stored in a data register formed on the single-chip. The data register provides control bits to the tuning components that include a programmable resistor responsive to the control bits to vary the programmable resistor to adjust programmed center frequency.

Tunable bandpass filter

A method and apparatus for temperature compensation for data converters in a software defined radio. Specifically, the system and method are teach monitoring the temperature of critical signal processing components such as band pass filters, ADCs and DACs and retrieving modulator coefficients in response to the temperatures and the like. The modulator coefficients are then used to compensate for temperature changes, performance changes and the like.

Method and apparatus for temperature compensation for data converters for automobile applications

A cellular radio architecture that includes a programmable bandpass sampling radio frequency front-end and an optimized digital baseband. The architecture includes a receiver module having a plurality of signal channels for different frequency bands, where each signal channel in the receiver module includes a receiver delta-sigma modulator that converts analog receive signals to a representative digital signal. The architecture also includes a transmitter module having a transmitter delta-sigma modulator for converting digital data bits to analog transmit signals, where the transmitter module includes a power amplifier and a switch for directing the transmit signals to one of the signal paths. The architecture also includes a dual self-cancellation circuit providing digital and analog cancellation of the transmit signal in the receiver module.

Dynamic range of wideband RF front end using delta sigma converters with envelope tracking and injected digitally equalized transmit signal

A wide bandwidth radio system designed to adapt to various global radio standards and, more particularly, to a radio receiver composed of a demodulator operative to work in a delta sigma mode and a Nyquist mode, and wherein a filter and feedback loop may utilized in response to the modulation mode of an RF signal.

Method and apparatus for hybrid delta-sigma and Nyquist data converters

A cellular radio architecture that includes a multiplexer coupled to an antenna structure and including multiple signal paths, where each signal path includes a bandpass filter that passes a different frequency band than the other bandpass filters and a circulator that provides signal isolation between the transmit signals and the receive signals. The architecture also includes a receiver module having a separate signal channel for each of the signal paths in the multiplexer, where each signal channel in the receiver module includes a receiver delta-sigma modulator that converts analog receive signals to a representative digital signal. The delta-sigma modulator includes an LC filter having a plurality of LC resonator circuits, a plurality of transconductance amplifiers and a plurality of integrator circuits, where a combination of one resonator circuit, transconductance amplifier and integrator circuit represents a two-order stage of the LC filter.

Software programmable, multi-segment capture bandwidth, delta-sigma modulators for flexible radio communication systems

A cellular radio architecture that includes an RF transmitter having a digital signal processor, a digital-to-analog converter (DAC) module that converts digital bits from the processor to an analog signal, a tunable bandpass filter that removes frequencies in the analog signal outside of a frequency band of interest, and a power amplifier that amplifies the filtered analog signal. The architecture also includes a calibration feedback device that receives the amplified analog signal and provides a feedback signal to the processor for calibrating the digital signal to provide amplified amplifier pre-distortion. The processor employs a noise-shaping operation to shape the analog signal from the DAC to remove quantization noise in an immediate vicinity of the signal to improve signal-to-noise ratio, performs an infinite impulse response process to lower a noise floor in the analog signal, and provides pre-distortion of the digital signal to compensate for non-linearties of the power amplifier.

Digital predistortion linearization for power amplifiers

A cellular radio architecture for a vehicle that includes a receiver module having a receiver delta-sigma modulator that converts analog receive signals to a representative digital signal. The architecture further includes a transmitter module having a transmitter delta-sigma modulator for converting digital data bits to analog transmit signals. Portions of the receiver and transmitter modules are fabricated with indium phosphide (InP) technologies and portions of the receiver and transmitter modules are fabricated with CMOS technologies.

Optimized data converter design using mixed semiconductor technology for cellular communications

A cellular radio architecture that includes a receiver module having a delta-sigma modulator that converts analog signals to digital signals and a Fast-Fourier transform (FFT) circuit that converts the digital signals to frequency spectrum signals. The architecture also includes a moving average circuit that smoothes out the frequency spectrum signals by applying a moving average to the signals. The architecture further includes a differentiator circuit that differentiates the frequency spectrum signals to make the signals linear, and a minimum finding circuit that converts the differentiated frequency spectrum signals into positive values for frequencies above a notch frequency in the differentiated signals and negative values for frequencies below the notch frequency in the differentiated signals. A transition between the positive and negative values is compared to a desired notch frequency value, and if the difference is greater than a predetermined threshold, an adaptive control circuit calibrates the modulator.

Testing tone free close loop notch frequency calibration for delta-sigma data converters

A cellular radio architecture that includes a transceiver front-end circuit including an antenna and a switch module having a switching network that directs analog transmit signals to be transmitted to the antenna and receives receive signals from the antenna. The architecture further includes a receiver module having a separate signal channel for each of the signal paths in the multiplexer module, where each signal channel in the receiver module includes a receiver delta-sigma modulator that converts analog receive signals to a representative digital signal. The architecture also includes a transmitter module having a transmitter delta-sigma modulator for converting digital data bits to the transmit signals. The transmitter module includes a tunable bandpass filter and a power amplifier for amplifying the transmit signals before transmitting. The architecture also includes a calibration feedback and switch module that receives the amplified signals from the power amplifier.

Calibration techniques for sigma delta transceivers

A cellular radio architecture for a vehicle that includes a triplexer coupled to an antenna structure and including three signal paths, where each signal path includes a bandpass filter that passes a different frequency band than the other bandpass filters and a circulator that provides signal isolation between the transmit signals and the receive signals. The architecture also includes a receiver module having a separate signal channel for each of the signal paths in the triplexer, where each signal channel in the receiver module includes a receiver delta-sigma modulator that converts analog receive signals to a representative digital signal. The delta-sigma modulator includes an LC filter having a plurality of LC resonator circuits, a plurality of transconductance amplifiers and a plurality of integrator circuits, where a combination of one resonator circuit, transconductance amplifier and integrator circuit represents a two-order stage of the LC filter.

Software programmable, multi-segment capture bandwidth, delta-sigma modulators for cellular communications

A circuit for correcting time encoder errors including a time encoder having a time encoder input, a time encoder output, and a current summing point, and a pulse width modifier coupled to the time encoder output, the pulse width modifier having a current output coupled to the current summing point, and having a corrected output. The pulse width modifier is configured to calibrate duty cycle errors and nonlinearity errors on the time encoder output, to correct the duty cycle errors and the nonlinearity errors on the time encoder output, and to output the corrected output.

Correction technique for analog pulse processing time encoder

An RF transmitter module for a cellular radio that includes a delta-sigma modulator having a plurality of interleaving dynamic element matching (DEM) circuits providing interleaved digital bits at a reduced clock rate. An interleaver controller controls the DEM circuits so as to provide groups of the digital bits at different points in time. In one embodiment, a summation junction adds the groups of the digital bits to provide a continuous stream of the interleaved digital bits, a DAC converts the stream of interleaved digital bits to an analog signal, and a power amplifier amplifies the analog signal.

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Malibu, CA, United States of America

Cynthia D Baringer