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.

The invention provides a system for conversion between analog domain and digital domain with mismatch error shaping, including a DAC, a first injection circuit coupled to the DAC, and a second injection circuit coupled to the DAC. The DAC generates a first analog value in response to a first digital value, and generates a second analog value in response to a second digital value. The first injection circuit enables an analog injection value to be injected to the second analog value when the DAC generates the second analog value, wherein the analog injection value is converted from a digital injection value formed by a subset of bits of the first digital value. The second injection circuit injects the digital injection value to the second digital value, or combines the digital injection value and a related value obtained according to the second analog value.

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.

A cellular radio architecture that includes a receiver module having a delta-sigma modulator that includes a plurality of gm cells configured in stages, where each stage includes at least two gm cells and an LC filter circuit. The gm cells in each stage can be controlled to be active or inactive to convert, for example, the modulator from a fourth order modulator to a second order modulator to reduce power dissipation. Further, the gm cells can be controlled to optimize a dynamic range of the modulator and to redirect current from inactive cells to active cells in order to optimize power consumption.

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.

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.

A cellular radio architecture that includes a receiver module having a delta-sigma modulator that includes a plurality of gm cells configured in stages, where each stage includes at least two gm cells and an LC filter circuit. The gm cells in each stage can be controlled to be active or inactive to convert, for example, the modulator from a fourth order modulator to a second order modulator to reduce power dissipation. Further, the gm cells can be controlled to optimize a dynamic range of the modulator and to redirect current from inactive cells to active cells in order to optimize power consumption.

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.

A cellular radio architecture that includes a programmable bandpass sampling radio frequency front-end and an optimized digital baseband. The architecture includes a multiplexer having signal paths that include 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 architecture further 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 in the multiplexer.

The invention provides a system for conversion between analog domain and digital domain with mismatch error shaping, including a DAC, a first injection circuit couple to the DAC, and a second injection circuit coupled to the DAC. The DAC generates a first analog value in response to a first digital value, and generates a second analog value in response to a second digital value. The first injection circuit enables an analog injection value to be injected to the second analog value when the DAC generates the second analog value, wherein the analog injection value is converted from a digital injection value formed by a subset of bits of the first digital value. The second injection circuit combines the digital injection value and one of the following: the second digital value and a related value obtained according to the second analog value.