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.

A wideband receiver system comprises a wideband analog-to-digital converter (ADC) module and a digital frontend (DFE) module. The wideband ADC is configured to concurrently digitize a band of frequencies comprising a plurality of desired channels and a plurality of undesired channels. The DFE module is coupled to the digital in-phase and quadrature signals. The DFE module is configured to select the plurality of desired channels from the digitized band of frequencies, and generate an intermediate frequency (IF) signal comprising the selected plurality of desired channels and having a bandwidth that is less than a bandwidth of the band of frequencies, where the generation comprises frequency shifting of the selected plurality of desired channels. The IF signal may be a digital signal and the DFE is configured to output the IF signal via a serial or parallel interface.

A superconducting multi-bit digital mixer, designed using rapid single flux quantum (RSFQ) logic, for multiplying two independent digital streams, at least one of these comprising a plurality of parallel bit lines, wherein the output is also a similar plurality of bit lines. In a preferred embodiment, one of the digital streams represents a local oscillator signal, and the other digital stream digital radio frequency input from an analog-to-digital converter. The multi-bit mixer comprises an array of bit-slices, with the local oscillator signal generated using shift registers. This multi-bit mixer is suitable for an integrated circuit with application to a broadband digital radio frequency receiver, a digital correlation receiver, or a digital radio frequency transmitter. A synchronous pulse distribution network is used to ensure proper operation at data rates of 20 GHz or above.

An Interleaved Radio Frequency Digital-to-Analog Converter (RF DAC) suitable for use in cellular base stations and optimized to give both a wide RF tuning range and a wide RF bandwidth is disclosed. The RF DAC uses two levels of interleaving, the first providing a direct conversion path from Base Band (BB) to RF, and the second providing a variable interleaving factor through the use of summation to optimize the output bandwidth as a function of the RF center frequency. Digital Interpolation, including an arbitrary sample rate conversion filter, allows the RF DAC to operate from a wide range of possible BB sample rates and the DAC sample rate is a fixed ratio of the RF center frequency. As a result, the spurious outputs from the RF DAC are in known locations that are relatively easy to filter out, minimizing the frequency planning tasks required for a complete RF system design.

An example successive approximation (SAR) analog-to-digital converter (ADC) includes: a track-and-hold (T/H) circuit configured to receive an analog input signal; a digital-to-analog converter (DAC); an adder having inputs coupled to outputs of the T/H circuit and the DAC; a comparison circuit coupled to an output of the adder and configured to perform a comparison operation; and a control circuit, coupled to an output of the comparison circuit, configured to: receive a selected resolution; gate the comparison operation of the comparison circuit based on the selected resolution; and generate a digital output signal having the selected resolution.

Techniques to dynamically adjust the corner frequency of a high-pass filter in response to a time-domain amplitude value of an output signal, thereby preserving accuracy while promptly recovering the signal's baseline value. A system can be configured to filter frequency-domain values of an input signal based on a filtering characteristic. The filtering characteristic can be set dynamically in response to a time-domain value of an amplitude of an output signal. The filtering characteristic can comprise a corner frequency, and the system can include a high-pass filter configured to filter out frequency components at frequencies lower than the corner frequency. The system is configured to dynamically change the corner frequency from a first value to a second value, in response to the time-domain value of the amplitude crossing a threshold value. The system may dynamically change the corner frequency within a time interval after the crossing.

The present disclosure relates to a ZigBee/Bluetooth dual-mode radio frequency transceiver architecture, in which, a dual-mode baseband and firmware determines hardware parameter of a receiving module or sending module based on a first mode or a second mode; a radio frequency front-end module is used for receiving or sending a first mode signal or a second mode signal; a receiving module is used for converting the first mode signal received by the radio frequency front-end module into a first mode baseband digital signal, or converting the second mode signal received by the radio frequency front-end module into a second mode baseband digital signal and outputting the first mode baseband digital signal or the second mode baseband digital signal to the dual-mode baseband and firmware; a sending module is used for converting the first mode baseband digital signal outputted by dual-mode baseband and firmware into the first mode signal.

The present disclosure relates to a ZigBee/Bluetooth dual-mode radio frequency transceiver architecture, in which, a dual-mode baseband and firmware determines hardware parameter of a receiving module or sending module based on a first mode or a second mode; a radio frequency front-end module is used for receiving or sending a first mode signal or a second mode signal; a receiving module is used for converting the first mode signal received by the radio frequency front-end module into a first mode baseband digital signal, or converting the second mode signal received by the radio frequency front-end module into a second mode baseband digital signal and outputting the first mode baseband digital signal or the second mode baseband digital signal to the dual-mode baseband and firmware; a sending module is used for converting the first mode baseband digital signal outputted by dual-mode baseband and firmware into the first mode signal.

A wideband receiver system comprises a wideband analog-to-digital converter (ADC) module and a digital frontend (DFE) module. The wideband ADC is configured to concurrently digitize a band of frequencies comprising a plurality of desired channels and a plurality of undesired channels. The DFE module is coupled to the digital in-phase and quadrature signals. The DFE module is configured to select the plurality of desired channels from the digitized band of frequencies, and generate an intermediate frequency (IF) signal comprising the selected plurality of desired channels and having a bandwidth that is less than a bandwidth of the band of frequencies, where the generation comprises frequency shifting of the selected plurality of desired channels. The IF signal may be a digital signal and the DFE is configured to output the IF signal via a serial or parallel interface.

A digital down converter with an equalizer translates an ADC output signal to a low frequency spectral region, followed by decimation. All operations of correction of the processed signal are carried out with a reduced sampling rate compared with sampling rates of the prior art. Equalization is performed only in a frequency pass band of the down converter. The achieved reduction of the required computation resources is sufficient to enable the down converter with equalization to operate in a real time mode.