Radio-frequency (RF) receivers having bandpass sigma-delta analog sigma analog-to-digital converters (ADC) designed to digitize signals in the RF domain are described. Such bandpass ADCs utilize one or more of the following techniques to enhance noise immunity and reduce power consumption: generation of in-phase (I) and quadrature (Q) paths in the digital domain, n.sup.th order resonant bandpass filtering with n>1, and signal sub-sampling in an i.sup.th Nyquist zone with i>1. Compared to RF receivers in which the I and Q paths are generated in the analog domain, these RF receivers exhibit higher IRRs because they are not susceptible to in-phase/quadrature (IQ) mismatch. Using n.sup.th order resonant bandpass filtering with n>1 attenuates unwanted image tones. The bandpass ADC-based RF receivers described herein exhibit enhanced immunity to noise, achieving for example image rejection ratios (IRR) in excess of 95dB.

An analog to digital conversion circuit includes an analog to digital converter (ADC) circuit operable to convert an analog signal having an oscillation frequency into a first digital signal having a first data rate frequency, where the analog signal includes a set of pure tone components. The analog to digital conversion circuit further includes a digital decimation filtering circuit operable to convert the first digital signal into a second digital signal having a second data rate frequency. The analog to digital conversion circuit further includes a digital bandpass filter (BPF) circuit operable to convert the second digital signal into an outbound digital signal having a third data rate frequency, where the digital bandpass filter circuit is set to produce a bandpass region approximately centered at the oscillation frequency of the analog signal and having a bandwidth tuned for filtering a pure tone.

Radio-frequency (RF) receivers having bandpass sigma-delta analog sigma analog-to-digital converters (ADC) designed to digitize signals in the RF domain are described. Such bandpass ADCs utilize one or more of the following techniques to enhance noise immunity and reduce power consumption: generation of in-phase (I) and quadrature (Q) paths in the digital domain, n.sup.th order resonant bandpass filtering with n>1, and signal sub-sampling in an i.sup.th Nyquist zone with i>1. Compared to RF receivers in which the I and Q paths are generated in the analog domain, these RF receivers exhibit higher IRRs because they are not susceptible to in-phase/quadrature (IQ) mismatch. Using n.sup.th order resonant bandpass filtering with n>1 attenuates unwanted image tones. The bandpass ADC-based RF receivers described herein exhibit enhanced immunity to noise, achieving for example image rejection ratios (IRR) in excess of 95 dB.

A baseband processing unit includes a baseband processor configured to receive a plurality of component carriers of a radio access technology wireless service, and a delta-sigma digitization interface configured to digitize at least one carrier signal of the plurality of component carriers into a digitized bit stream, for transport over a transport medium, by (i) oversampling the at least one carrier signal, (ii) quantizing the oversampled carrier signal into the digitized bit stream using two or fewer quantization bits.

Method and apparatus for nonlinear signal processing include mitigation of outlier noise in the process of analog-to-digital conversion and adaptive real-time signal conditioning, processing, analysis, quantification, comparison, and control. Methods, processes and apparatus for real-time measuring and analysis of variables include statistical analysis and generic measurement systems and processes which are not specially adapted for any specific variables, or to one particular environment. Methods and corresponding apparatus for mitigation of electromagnetic interference, for improving properties of electronic devices, and for improving and/or enabling coexistence of a plurality of electronic devices include post-processing analysis of measured variables and post-processing statistical analysis. Methods, processes and apparatus for secure communications include low-power communications and physical-layer steganography.

An analog to digital conversion circuit includes an analog to digital converter (ADC) circuit operable to convert an analog signal having an oscillation frequency into a first digital signal having a first data rate frequency, where the analog signal includes a set of pure tone components. The analog to digital conversion circuit further includes a digital decimation filtering circuit operable to convert the first digital signal into a second digital signal having a second data rate frequency. The analog to digital conversion circuit further includes a digital bandpass filter (BPF) circuit operable to convert the second digital signal into an outbound digital signal having a third data rate frequency, where the digital bandpass filter circuit is set to produce a bandpass region approximately centered at the oscillation frequency of the analog signal and having a bandwidth tuned for filtering a pure tone.

A baseband processing unit includes a baseband processor configured to receive a plurality of component carriers of a radio access technology wireless service, and a delta-sigma digitization interface configured to digitize at least one carrier signal of the plurality of component carriers into a digitized bit stream, for transport over a transport medium, by (i) oversampling the at least one carrier signal, (ii) quantizing the oversampled carrier signal into the digitized bit stream using two or fewer quantization bits.

The disclosure provides a receiver with high dynamic range. The receiver includes a photodiode that generates a current signal. A coupling capacitor is coupled to the photodiode, and generates a modulation signal in response to the current signal received from the photodiode. A sigma delta analog to digital converter (ADC) is coupled to the coupling capacitor, and generates a digital data in response to the modulation signal. A digital mixer is coupled to the sigma delta ADC, and generates an in-phase component and a quadrature component corresponding to the digital data. A processor is coupled to the digital mixer, and processes the in-phase component and the quadrature component corresponding to the digital data.

A baseband processing unit includes a baseband processor configured to receive a plurality of component carriers of a radio access technology wireless service, and a delta-sigma digitization interface configured to digitize at least one carrier signal of the plurality of component carriers into a digitized bit stream, for transport over a transport medium, by (i) oversampling the at least one carrier signal, (ii) quantizing the oversampled carrier signal into the digitized bit stream using two or fewer quantization bits.

A resonator circuit has first to sixth transconductance units and the first to fourth connectors. The first transconductance unit has the first top, bottom, and control terminals. The second transconductance unit has the second top terminal connected to the first bottom terminal and has the second bottom and control terminals. The third transconductance unit has a third top terminal connected to the first top terminal and has the third bottom and control terminals. The fourth transconductance unit has the fourth top, bottom, and control terminals. The fifth transconductance unit has the fifth top terminal connected to the fourth bottom terminal and has the fifth bottom and control terminals. The sixth transconductance unit has the sixth top terminal connected to the fourth top terminal and has the sixth bottom and control terminals.