The present invention relates to nonlinear signal processing, and, in particular, to adaptive nonlinear filtering of real-, complex-, and vector-valued signals utilizing analog Nonlinear Differential Limiters (NDLs), and to adaptive real-time signal conditioning, processing, analysis, quantification, comparison, and control. More generally, this invention relates to methods, processes and apparatus for real-time measuring and analysis of variables, and to generic measurement systems and processes. This invention also relates to methods and corresponding apparatus for measuring which extend to different applications and provide results other than instantaneous values of variables. The invention further relates to post-processing analysis of measured variables and to statistical analysis. The NDL-based filtering method and apparatus enable improvements in the overall properties of electronic devices including, but not limited to, improvements in performance, reduction in size, weight, cost, and power consumption, and, in particular for wireless devices, NDLs enable improvements in spectrum usage efficiency.

This document discusses apparatus and methods for compensating non-linearity of digital-to-time converters (DTCs). In an example, a wireless device can include a digital-to-time converter (DTC) configured to receive a phase data information from a baseband processor and to provide a first modulation signal for generating a wireless signal, a detector configure to receive the first modulation signal and provide an indication of nonlinearities of the DTC, and a pre-distortion module configured to provide pre-distortion information to the DTC using the indication of nonlinearities.

This document discusses apparatus and methods for compensating non-linearity of digital-to-time converters (DTCs). In an example, a wireless device can include a digital-to-time converter (DTC) configured to receive a phase data information from a baseband processor and to provide a first modulation signal for generating a wireless signal, a detector configure to receive the first modulation signal and provide an indication of nonlinearities of the DTC, and a pre-distortion module configured to provide pre-distortion information to the DTC using the indication of nonlinearities.

An analog to digital converter (ADC) senses an analog signal (e.g., a load current) to generate a digital signal. The ADC operates based on a load voltage produced based on charging of an element (e.g., a capacitor) by a load current and a digital to analog converter (DAC) output current (e.g., from a N-bit DAC). The ADC generates a digital output signal representative of a difference between the load voltage and a reference voltage. This digital output signal is used directly, or after digital signal processing, to operate an N-bit DAC to generate a DAC output current that tracks the load current. The digital output signal provided to the N-bit DAC is an inverse function of the load current. The ADC is operative to sense very low currents (e.g., currents as low as is of pico-amps) and consume very little power (e.g., less than 2 W).

An analog to digital converter (ADC) senses an analog signal (e.g., a load current) to generate a digital signal. The ADC operates based on a load voltage produced based on charging of an element (e.g., a capacitor) by a load current and a digital to analog converter (DAC) output current (e.g., from a N-bit DAC). The ADC generates a digital output signal representative of a difference between the load voltage and a reference voltage. This digital output signal is used directly, or after digital signal processing, to operate an N-bit DAC to generate a DAC output current that tracks the load current. The digital output signal provided to the N-bit DAC is an inverse function of the load current. The ADC is operative to sense very low currents (e.g., currents as low as is of pico-amps) and consume very little power (e.g., less than 2 W).

An analog to digital converter (ADC) senses an analog signal (e.g., a load current) to generate a digital signal. The ADC operates based on a load voltage produced based on charging of an element (e.g., a capacitor) by a load current and a digital to analog converter (DAC) output current (e.g., from a N-bit DAC). The ADC generates a digital output signal representative of a difference between the load voltage and a reference voltage. This digital output signal is used directly, or after digital signal processing, to operate an N-bit DAC to generate a DAC output current that tracks the load current. The digital output signal provided to the N-bit DAC is an inverse function of the load current. The ADC is operative to sense very low currents (e.g., currents as low as 1s of pico-amps) and consume very little power (e.g., less than 2 W).

An analog to digital converter (ADC) senses an analog signal (e.g., a load current) to generate a digital signal. The ADC operates based on a load voltage produced based on charging of an element (e.g., a capacitor) by a load current and a digital to analog converter (DAC) output current (e.g., from a N-bit DAC). The ADC generates a digital output signal representative of a difference between the load voltage and a reference voltage. This digital output signal is used directly, or after digital signal processing, to operate an N-bit DAC to generate a DAC output current that tracks the load current. The digital output signal provided to the N-bit DAC is an inverse function of the load current. The ADC is operative to sense very low currents (e.g., currents as low as 1s of pico-amps) and consume very little power (e.g., less than 2 W).

A method for compensating signal nonlinearities includes generating a local oscillator (LO) signal and performing phase modulation of the LO signal to generate a phase-modulated LO signal. The phase modulation is based on applying at least one digital-to-time converter (DTC) code of a plurality of DTC codes to a rising edge signal portion and a falling edge signal portion associated with the LO signal. Nonlinearities associated with the rising edge signal portion and the falling edge signal portion are determined. The at least one DTC code is adjusted based on the nonlinearities.

A method for compensating signal nonlinearities includes generating a local oscillator (LO) signal and performing phase modulation of the LO signal to generate a phase-modulated LO signal. The phase modulation is based on applying at least one digital-to-time converter (DTC) code of a plurality of DTC codes to a rising edge signal portion and a falling edge signal portion associated with the LO signal. Nonlinearities associated with the rising edge signal portion and the falling edge signal portion are determined. The at least one DTC code is adjusted based on the nonlinearities.