A delta-sigma modulation apparatus performs delta-sigma modulation on a first signal as an input signal and outputs a second signal, outputs, using the second signal and a third signal generated through a transmission process of the second signal, a fourth signal that is an approximated value of a signal which is generated through at least part of the transmission process, and performs the delta-sigma modulation on the first signal using the fourth signal and outputs the second signal.

A monolithic integrated circuit (IC), and method of manufacturing same, that includes all RF front end or transceiver elements for a portable communication device, including a power amplifier (PA), a matching, coupling and filtering network, and an antenna switch to couple the conditioned PA signal to an antenna. An output signal sensor senses at least a voltage amplitude of the signal switched by the antenna switch, and signals a PA control circuit to limit PA output power in response to excessive values of sensed output. Stacks of multiple FETs in series to operate as a switching device may be used for implementation of the RF front end, and the method and apparatus of such stacks are claimed as subcombinations. An iClass PA architecture is described that dissipatively terminates unwanted harmonics of the PA output signal. A preferred embodiment of the RF transceiver IC includes two distinct PA circuits, two distinct receive signal amplifier circuits, and a four-way antenna switch to selectably couple a single antenna connection to any one of the four circuits.

An antenna module includes a dielectric substrate, a ground electrode, a power feeding element (121) and a power feeding element (122) each facing the ground electrode, and power feeding wirings (141) and (142). The power feeding wiring (141) transmits a radio frequency signal to a power feeding point (SP1) of the power feeding element (121). The power feeding wiring (142) transmits a radio frequency signal to a power feeding point (SP2) of the power feeding element (122). A frequency of a radio wave from the power feeding element (122) is higher than a frequency of a radio wave from the power feeding element (121). The power feeding wiring (142) includes a via rises from the ground electrode side to the power feeding element (122) at a position different from the power feeding point (SP2) and a wiring pattern that connects the via and the power feeding point (SP2).

A spread-spectrum transmitter is disclosed. The transmitter includes a modulator configured to produce an intermediate frequency signal, a frequency shifter configured to shift the intermediate frequency factor by a first factor, and a local oscillator (LO) configured to generate a LO signal. The transmitter further includes a ramp signal generator configured to determine the value of the first factor and a second factor, is configured to transmit the value of the factor to the frequency shifter, is configured to transmit the value of the second factor to the LO, where the frequency of the intermediate frequency signal shifted by the first factor is shifted synchronously with the frequency of the LO signal shifted by the second factor. The transmitter includes a mixer configured to mix the shifted intermediate frequency with the shifted LO signal that has been shifted by the second factor, producing a spread leaked LO signal.

A method for predistortion including receiving a plurality of input signals forming a multiple-input signal in a multiple-input multiple-output system, generating a pre-distorted multiple-input signal from the received multiple-input signal, generating a multiple-output signal by feeding the pre-distorted multiple-input signal into a multiple-input and multiple-output transmitter, estimating impairments generated by the multiple-input and multiple-output transmitter, the impairments including nonlinear crosstalk between distinct ones of the plurality of input signals; and adjusting the pre-distorted multiple-input signal to compensate for the estimated impairments.

Systems, circuitries, and methods for predistorting a digital signal in a transmit chain based on a predistortion function are provided. A method includes shifting a center frequency of an input signal by an offset to generate an adapted signal; predistorting the adapted signal based on a predistortion function to generate a predistorted adapted signal; reverting the shifting of the center frequency of the predistorted adapted signal by the offset to generate a predistorted signal; and causing transmission of the predistorted signal by a transmit chain.

Certain aspects of the present disclosure provide techniques for training a digital pre-distorter (DPD) using real-time over-the-air transmissions and receptions by a user equipment (UE). A method for training the DPD generally includes transmitting a signal, generated by a transmitter front end, via a first port; sampling the signal, received over the air, at a second port; performing signal processing cleaning (e.g., synchronization, linear over-the-air channel estimation and equalization); calculating coefficients for a DPD; and configuring the DPD with the coefficients, for use in digitally pre-distorting sub sequent transmissions.

Efficient amplifier operation. In one aspect, there is a radio transceiver device. The radio transceiver device includes a distorting unit configured to receive an input signal and distort the received input signal, thereby producing a distorted input signal. The radio transceiver device further includes a limiter configured to receive the distorted input signal and produce a limited signal based on the received distorted input signal. The radio transceiver device further includes a power amplifier configured to receive the limited signal and amplify the limited signal, thereby producing an amplified limited signal.

Methods, systems, and devices for wireless communications are described. For example, a transmitting wireless device, such as a user equipment or a base station, may apply a first set of digital pre-distortion (DPD) coefficients to a plurality of antenna elements to form a first transmit beam. The wireless device may determine to switch from using the first transmit beam to using a second transmit beam that is different from the first transmit beam and may apply a second set of DPD coefficients to the plurality of antenna elements to form the second transmit beam, where the second set of DPD coefficients is different from the first set of DPD coefficients. The wireless device may transmit signaling using the second transmit beam based at least in part on applying the second set of DPD coefficients.

Methods and devices are discussed. A device configured to operate in a network comprises communication circuitry and a transceiver.