An apparatus such as an electronic circuit includes an input operable to receive an input signal; a dynamic common mode adjustor operable to: i) derive a differential signal from the received input signal, and ii) control an offset of the differential signal as a function of the received input signal to produce an offset differential signal; and an output operable to output the offset differential signal. In one arrangement, the offset differential signal outputted from the output includes a first signal and a second signal; a difference between the second signal and the first signal proportionally varies with respect to the received input signal.

An apparatus such as an electronic circuit includes an input operable to receive an input signal; a dynamic common mode adjustor operable to: i) derive a differential signal from the received input signal, and ii) control an offset of the differential signal as a function of the received input signal to produce an offset differential signal; and an output operable to output the offset differential signal. In one arrangement, the offset differential signal outputted from the output includes a first signal and a second signal; a difference between the second signal and the first signal proportionally varies with respect to the received input signal.

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 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.

An integrated circuit is disclosed. The integrated circuit includes a first equalizer circuit and a second equalizer circuit. The first equalizer circuit is configured to equalize an input signal which is added by offset voltages that are different from each other, to generate output signals with voltage levels that are different from each other. The second equalizer circuit coupled to the first equalizer circuit. The second equalizer circuit includes a first equalizer unit and a second equalizer unit. The first equalizer unit is configured to equalize the output signals, to generate odd data signals. The second equalizer unit is coupled to the first equalizer unit and configured to equalize the output signals, to generate even data signals. A method is also disclosed herein.

An integrated circuit is disclosed. The integrated circuit includes a first equalizer circuit and a second equalizer circuit. The first equalizer circuit is configured to equalize an input signal which is added by offset voltages that are different from each other, to generate output signals with voltage levels that are different from each other. The second equalizer circuit coupled to the first equalizer circuit. The second equalizer circuit includes a first equalizer unit and a second equalizer unit. The first equalizer unit is configured to equalize the output signals, to generate odd data signals. The second equalizer unit is coupled to the first equalizer unit and configured to equalize the output signals, to generate even data signals. A method is also disclosed herein.

Described herein are apparatus and methods for realization of time interleaved digital-to-analog converters (DACs) by detecting and aligning phase mismatches. In an implementation, a N-time interleaved DAC includes N DACs and N replica DACs, where a first set of N/2 DACs operate at a clock A and a second set of N/2 DACs operate at a clock B, and where N is at least two. The phase detector generates a phase detection output by comparing outputs of the first and second set of N/2 replica DACs with a multiplexor (MUX) clock, where the MUX clock is a multiple of a frequency of the clock A or the clock B. The clock A and the clock B are aligned with the MUX clock by advancing a phase of the clock A and the clock B until the phase detection output achieves a zero crossing.

Described herein are apparatus and methods for realization of time interleaved digital-to-analog converters (DACs) by detecting and aligning phase mismatches. In an implementation, a N-time interleaved DAC includes N DACs and N replica DACs, where a first set of N/2 DACs operate at a clock A and a second set of N/2 DACs operate at a clock B, and where N is at least two. The phase detector generates a phase detection output by comparing outputs of the first and second set of N/2 replica DACs with a multiplexor (MUX) clock, where the MUX clock is a multiple of a frequency of the clock A or the clock B. The clock A and the clock B are aligned with the MUX clock by advancing a phase of the clock A and the clock B until the phase detection output achieves a zero crossing.

A modulator comprises one or more resonators. Each resonator has a light confining closed loop structure, such as a ring structure, and two, three or more electrodes associated with the light-confining structure, and may be a micro-resonator. An optical signal is modulated by a digital signal using the resonator. The procedure comprises obtaining the digital signal, mapping the signal using a mapping function to produce a transformed digital signal, the transformed digital signal being selected to produce, say linear, output from the resonator, inputting the transformed digital signal via electrodes onto the resonator; and modulating the optical signal via coupling from the resonator. Suitable mapping produces 16 QAM and other modulation schemes.

A modulator comprises one or more resonators. Each resonator has a light confining closed loop structure, such as a ring structure, and two, three or more electrodes associated with the light-confining structure, and may be a micro-resonator. An optical signal is modulated by a digital signal using the resonator. The procedure comprises obtaining the digital signal, mapping the signal using a mapping function to produce a transformed digital signal, the transformed digital signal being selected to produce, say linear, output from the resonator, inputting the transformed digital signal via electrodes onto the resonator; and modulating the optical signal via coupling from the resonator. Suitable mapping produces 16 QAM and other modulation schemes.