Embodiments of the disclosure provide a differential clock duty cycle correction (DCC) circuit, including: a hybrid current injector including current sources for generating a correction current, wherein the correction current is added to a clock signal of a first polarity at a first correction node and subtracted from a clock signal of an opposite polarity at a second correction node, and wherein a plurality of the current sources in the hybrid current injector are controlled by a first portion of a n-bit DAC code to generate the correction current; and a current DAC for receiving a second, different portion of the n-bit DAC code and for outputting a corresponding reference current to the current sources in the hybrid current injector, wherein the current sources generate the correction current in response to the reference current output by the current DAC for the second portion of the n-bit DAC code.

A communication system where a central node (base-station or access point) communicates with multiple clients in its neighbourhood using transparent immediate beam-forming. Resource allocation and channel access is such that the central node does not necessarily know when each client starts its transmission. Receive beam-forming in such a system is not possible, as beam-forming coefficients for each client should be selected according to the particular channel realization from that client to the central node. Each client is detected early in its transmission cycle, based on either a signature that is part of the physical characteristics unique to that client, or based on a signature that is intentionally inserted in the clients' signal, and accordingly adjusts its beam-forming coefficients.

A trimming resource includes an adjustable driver resource, a differential voltage generator, and a trim current generator. The adjustable driver resource produces an output signal. The differential voltage generator receives the output signal from the adjustable driver resource and produces a differential drive signal. The trim current generator derives a trim signal from the differential drive signal received from the differential voltage generator. According to one configuration, the trim current generator outputs the trim signal to an electronic component, correcting an operational parameter of the electronic component.

A digitally-controlled power amplifier (DPA) includes a radio frequency digital-to-analog converter (RF-DAC) constructed from nonlinearly weighted PA segments, a multiphase RF drive signal generator that drives the PA segments, and overdrive voltage control circuitry. The nonlinear weighting of the PA segments intrinsically compensates for amplitude-code-word dependent amplitude distortion (ACW-AM distortion) involved in the operation of the RF-DAC and the multiphase RF drive signal generator facilitates ACW-dependent phase distortion (ACW-PM distortion) reduction, thus obviating the need for complicated and efficiency-degrading digital predistortion. The overdrive voltage control circuitry is used to fine tune the RF output of the DPA and compensate for other non-idealities and external influences such as process, voltage, temperature (PVT), frequency and/or load impedance variations.

A digital-to-analog converter system has digital-to-analog converters, a common output, and a digital controller for transmitting first codes to one of the converters at a radio-frequency digital rate, and for transmitting second codes to another one of the converters at the same rate. The digital controller includes a timing system for operating each converter at the digital rate in a return-to-zero configuration, such that a signal from the first converter is transmitted to the common output while the second converter is reset, and vice versa. The digital-to-analog converter system can generate a radio-frequency analog signal having signals in first and second Nyquist zones simultaneously.

A frequency digital-to-analog converter (FDAC) for generating an analog frequency modulating signal from a digital frequency modulating signal includes a Least Significant Bit (LSB) DAC section and a Most Significant Bit (MSB) DAC section. The LSB DAC section comprises a plurality of LSB DACs and is configured to switch between the LSB DACs for mitigating mismatch. The MSB DAC section comprises a plurality of MSB DAC cells and is configured to switch the MSB DAC cells according to a predefined sequence during a period of the digital frequency modulating signal.

A transceiver includes a first digital-to-analog converter (DAC) configured to receive a first digital code and output a first current to a first node; a second DAC configured to receive a second digital code and output a second current to a second node; first and second shunt resistors configured to shunt the first node and second nodes to a DC (direct current) node; a first DC coupling resistor coupling the first node to a third node; a second DC coupling resistor coupling the second node to the third node; an AC (alternate current) coupling capacitor coupling the third node to a fourth node; a transimpedance amplifier configured to receive an input current from the fourth node and output an output current to a fifth node; an inductive load configured to shunt the fifth node to a DC node; and an analog-to-digital conversion unit configured to receive a voltage at the fifth node and output a third digital code.

A digitally-controlled power amplifier (DPA) includes a radio frequency digital-to-analog converter (RF-DAC) constructed from nonlinearly weighted PA segments, a multiphase RF drive signal generator that drives the PA segments, and overdrive voltage control circuitry. The nonlinear weighting of the PA segments intrinsically compensates for amplitude-code-word dependent amplitude distortion (ACW-AM distortion) involved in the operation of the RF-DAC and the multiphase RF drive signal generator facilitates ACW-dependent phase distortion (ACW-PM distortion) reduction, thus obviating the need for complicated and efficiency-degrading digital predistortion. The overdrive voltage control circuitry is used to fine tune the RF output of the DPA and compensate for other non-idealities and external influences such as process, voltage, temperature (PVT), frequency and/or load impedance variations.

A multi-path dual-switch DAC refers to implementing multiple paths in a switch driver and only two switches in a DAC stack of a DAC unit. In addition to multiple paths configured to improve the driving ability of the input signals, the switch driver of a multi-path dual-switch DAC unit includes two or more logic gates configured to act as multiplexers combining some of the output signals from different paths. The use of such logic gates enables using only two switches in the DAC stack unit to receive the data. Furthermore, optionally, additional logic gates may be used to combine some other output signals from different paths to generate dummy signals, thus providing internal dummy logic. The multi-path dual-switch DACs described herein may advantageously use half-clock rate and reduce or eliminate supply modulation issues, while also reducing power consumption and improving linearity compared to traditional DAC architectures.

A wideband, frequency agile, radio frequency digital-to-analog converter (RF-DAC) based phase modulator includes first, second, and third RF-DACs, each configured to upconvert an input I/Q digital baseband signal pair to a local oscillator (LO) frequency but with the first RF-DAC being driven by a first set of LO clocks, the second RF-DAC being driven by a second set of LO clocks that is forty-five degrees out of phase with respect to the first set of LO clocks, and the third RF-DAC being driven by a third set of LO clocks that is a further forty-five degrees out of phase with respect to the second set of LO clocks. First, second, and third upconverted analog signals produced by the first, second, and third RF-DACs are combined to reinforce the fundamental LO component while canceling 3.sup.rd-order and 5.sup.th-order LO harmonics.