Abstract: A method for calibrating compensation values utilized by a compensation device in a transmitter includes: obtaining a plurality of output signals sequentially generated by the transmitter by processing a pair of input signals based on a plurality of pairs of compensation values as a plurality of feedback signals, where each feedback signal corresponds to one of the plurality of pairs of compensation values; obtaining a signal component of the feedback signals at a predetermined frequency as a portion of the feedback signals; determining a pair of equivalent impairment parameters in a calibration operation according to the plurality of pairs of compensation values and the portion of the feedback signals; and determining a pair of calibrated compensation values according to the pair of equivalent impairment parameters and providing the pair of calibrated compensation values to the compensation device.

Abstract: A power generator includes a power source and a control module coupled to the power source. The control module is configured to generate at least one control signal to vary a respective at least one of an output signal from the power source or an impedance between the power source and a load. The output signal includes a signal modulated by a pulse signal, and the control module is further configured to adjust the at least one control signal to vary at least one of an amplitude or a frequency of the output signal or the impedance between the power source and the load to control a shape of the pulse signal. The at least one of the amplitude, the frequency, or the impedance is adjusted in accordance with respective feedforward adjustments that vary in accordance with a respective sensed pulse parameter detected between a matching network and the load.

Abstract: An artificial intelligence (AI) driven linearizer for a transmitter, comprising an input interface for inputting linearizer signals comprising information carrying signals, and operating conditions parameter signals, other than the information carrying signal, wherein the operating conditions parameter signals represent metrics affecting transfer characteristics of the transmitter, over a selected operating range of the transmitter, and a predistortion actuator circuit configured with an AI predistortion model for predistorting at least part of the information carrying signal to produce predistorted signals, the predistortion model being configured to be operable for adaptation to said characteristics of the transmitter using a single set of model coefficients that are unchanged over said entirety of said selected operating range.

Abstract: A feedforward amplifier comprises a power amplifier that generates an amplified signal, an error correcting circuitry that generates a first error signal and a second error signal based on an error in the amplified signal; and an output circuitry. The output circuitry comprises: a first quadrature coupler, an output of a first error amplifier is connected to the quadrature coupler and an input of the first error amplifier is configured to receive the first error signal, and an output of a second error amplifier is connected to the quadrature coupler and an input of the second error amplifier is configured to receive the second error signal. The output circuitry generates an error compensation signal in the first quadrature coupler from the output signals of the first and second error amplifiers.

Abstract: Disclosed is a multi-band transmitter for transmitting a multi-band signal. The multi-band transmitter comprises: a pre-distortion unit including a first digital pre-distorter (DPD) which pre-distorts a first band signal and a second DPD which pre-distorts a second band signal discontinuous from the first band signal; a conversion unit which analog-converts the pre-distorted first band signal and the pre-distorted second band signal; an amplification unit including a first power amplifier (PA), which amplifies the analog-converted first band signal, and a second PA, which amplifies the analog-converted second band signal; and a feedback unit which digital-converts the amplified first band signal to feed the digital-converted first band signal back to the first DPD and digital-converts the amplified second band signal to feed the digital-converted second band signal back to the second DPD.

Abstract: An apparatus is disclosed for frequency-based predistortion signal generation. In an example aspect, the apparatus includes a predistortion linearizer circuit configured to be coupled to an input of an amplifier. The amplifier has non-linearities associated with multiple frequencies. The multiple frequencies include a first subset of frequencies and a second subset of frequencies. The predistortion linearizer circuit is also configured to accept an input signal. The predistortion linearizer circuit is additionally configured to generate, based on the input signal, a compensation signal to attenuate the non-linearities existing within the first subset of frequencies more than the non-linearities existing within the second subset of frequencies. The predistortion linearizer circuit is further configured to generate a pre-distorted signal based on the input signal and the compensation signal.

Abstract: An automatic level control (ALC) circuit includes an input configured to receive a radio frequency (RF) input signal, a level control circuit coupled to the input and configured to control a level of the RF input signal in response to a feedback signal, and an output coupled to the level control circuit and configured to output a level-controlled RF output signal. The ALC circuit further includes a feedback path coupled to the output and configured to sample the level-controlled RF output signal to determine an error detected in the level-controlled RF output signal, and to generate the feedback signal in accordance with the error. The ALC circuit still further includes a feedforward path coupled to the input and configured to emulate a frequency response in the feedback path and to adjust the error determined in the feedback path according to the emulated frequency response.

Abstract: Techniques for power amplifier trimming based on coefficients for digital pre-distortion (DPD) are disclosed. In certain embodiments, a mobile device includes a transceiver including a first DPD circuit that digitally pre-distorts a first digital transmit signal, a second DPD circuit that digitally pre-distorts a second digital transmit signal, and a coefficient comparator circuit that generates a trimming control signal based on comparing a first plurality of coefficients of the first DPD circuit to a second plurality of coefficients of the second DPD circuit. The mobile device further includes a front end system including a first power amplifier that amplifies a first radio frequency (RF) signal from the transceiver, a second power amplifier that amplifies a second RF signal from the transceiver, and a power amplifier trimming circuit that controls trimming of at least one of the first power amplifier or the second power amplifier based on the trimming control signal.

Abstract: An analog amplitude pre-distortion circuit includes a Radio Frequency, RF, input for receiving an RF signal. The circuit also includes an amplifier stage comprising an amplifier stage input for receiving the RF signal from the RF input, where the amplifier stage is operable to amplify the RF signal to produce an amplified RF signal. The circuit further includes a bias circuit. The bias circuit includes a detector stage for detecting an amplitude of the RF signal, and for producing a correction signal based on the amplitude of the RF signal. The bias circuit also includes a bias application stage coupled to the amplifier stage input.

Abstract: The present power amplifier linearizing module linearizes operation of a power amplifier and operates in parametrizing mode and operation mode. A processing module executes a feed-forward transfer functions set, which includes at least: a transfer function P and a summing function. The transfer function P derives a change signal ?Va relative to the control signal component received and the summing function summing the incremental change signal ?Va to an input signal to generate an adjusted input signal. A transfer function G uses the adjusted input signal to generate an RF signal representative of the amplifying of the adjusted input signal based on the control signal component. The processing module determines a linearizing control signal component based on the generated RF signal representative.

Abstract: An amplifier (T1) amplifies an input signal. A harmonic matching circuit (3) is connected to an output end of the amplifier (T1) via a first wire (W1). The harmonic matching circuit (3) includes a first inductor (L1) connected to the first wire (W1), a first capacitor (C1) connected in series to the first inductor (L1), a second inductor (L2) connected in parallel with the first inductor (L1), and a second capacitor (C2) connected in series to the second inductor (L2). The first inductor (L1) and the second inductor (L2) form a subtractive-polarity coupler which presents mutual inductance having subtractive polarity.

Abstract: Aspects of the present disclosure provide signal amplification. An example method generally includes amplifying a version of a first input signal with a power amplifier in a first state where a bias voltage of the power amplifier is set to a first voltage based on a first tracking mode; obtaining a first output signal of the power amplifier in a second state where the bias voltage is set to a second voltage less than the first voltage; determining a predistortion associated with the power amplifier based at least in part on the obtained first output signal; applying the predistortion to the first input signal; and amplifying a version of the predistorted first input signal with the power amplifier in a third state where the bias voltage is set to a third voltage based on a second tracking mode, wherein the third voltage is less than the first voltage.

Abstract: A digital phase shift circuit includes: a signal line extending in a predetermined direction; two inner lines disposed on both one side and another side of the signal line and separated a predetermined distance from the signal line; two outer lines provided at positions which are farther from the signal line than the inner lines on both the one side and the other side; a first grounding conductor electrically connected to one end of each of the inner lines and the outer lines; and a second grounding conductor electrically connected to other ends of the outer lines, and the predetermined distance is set to be less than 10 ?m.

Abstract: Provided is a modeling device performing calculation using an amplifier model that models an amplifier of which an internal state affecting a distortion characteristic varies, wherein the amplifier model includes a plurality of calculation models that model the amplifier in different internal states, and a combiner that combines the plurality of calculation models at a combination ratio corresponding to the internal state that varies.

Abstract: A device, method, and system for signal distortion pre-correction, and a composite system are disclosed. The device-includes: a signal distortion correction network module, a correction parameter trainer, a data collection module connected to an external power amplifier module, and a first conversion module. The data collection module is configured to perform time-division collection on output signals of channels of the power amplifier module and output analog feedback signals to the first conversion module. The first conversion module is configured to convert the analog feedback signals into digital feedback signals. The correction parameter trainer is configured to determine a correction parameter according to the digital feedback signals and a forward signal inputted. The signal distortion correction network module is configured to correct the forward signal based on the correction parameter and output a pre-corrected signal.

Abstract: Techniques are described for implementing multiband digital predistortion in a broadband transmitter in a manner that provides effective compensation of non-linear distortion arising from integration of a high-power amplifier (HPA). Embodiments segment the signal spectrum of a transmit signal into multiple sub-band signals and apply non-linear distortion compensation separately and concurrently for each sub-band signal. The resulting multi-band digital predistortion (mDPD) compensates both for in-band distortion and for distortions from non-linear interactions between the frequency sub-bands. The disclosed mDPD can provide enhanced performance features, such as handling of memory effects, reduced sampling rate requirements for DPD components, and minimizing detrimental spectral regrowth at the HPA output.

Abstract: A digital phase shifter of the present invention is a digital phase shifter in which digital phase shift circuits are cascade-connected, each of the digital phase shift circuits including a signal line, a pair of inner lines provided on both sides of the signal line, a pair of outer lines provided on outer sides of the inner lines, a first ground conductor connected to one ends of the inner lines and one ends of the outer lines, a second ground conductor connected to the other ends of the outer lines, and a pair of electronic switches provided between the other ends of the inner lines and the second ground conductor. The digital phase shift circuits include a multi-row structure constituted by a front row and a rear row, the front row and the rear row are adjacent to each other, and the ground pattern is connected to the front row at one point.

Abstract: A predistortion circuit for a wireless transmitter includes a signal input configured to receive a baseband signal. Further, the predistortion circuit includes a predistorter configured to generate a predistorted baseband signal using the baseband signal and a select of one of a first predistorter configuration and a second predistorter configuration.

Abstract: A parameter changing device according to the present disclosure includes: a multiplier multiplying a test signal by a back-off rate; a first distortion compensation simulation unit performing distortion compensation processing on a signal acquired by the multiplication, by using a stored parameter; a scaling unit scaling an output signal of the first distortion compensation simulation unit; a second distortion compensation simulation unit performing distortion compensation processing on the test signal, by using a parameter different from the first distortion compensation simulation unit; a differential unit calculating an error between a value of a signal acquired by the scaling and a value of an output signal of the second distortion compensation simulation unit; an approximation error minimization unit calculating a parameter of the second distortion compensation simulation unit minimizing the error; and an output unit outputting a parameter of the second distortion compensation simulation unit to a distor

Abstract: A base station for a wireless communication network is provided. The wireless communication network includes a plurality of base stations, each base station to serve one or more users. One or more users are served by a plurality of base stations to receive a first data signal from the base station and a second data signal from at least one further base station using multi-user superposition transmission, MUST. The base station includes a backhaul interface for a communication with one or more of the plurality of base stations of the wireless communication network. For transmitting the first data signal to one or more users served by the base station and by the further base station, the base station is configured to negotiate a MUST setting with the further base station via the backhaul interface, and map data of the first data signal using a first transmit constellation set according to the negotiated MUST setting.

Abstract: A drive circuit with predistortion. In some embodiments, a system includes a signal input, a predistortion circuit, and an amplifier circuit. The predistortion circuit may be operatively coupled to the signal input and to the amplifier circuit and configured to modify a radio frequency (RF) signal received at the signal input to cause the amplifier circuit to drive, into a load connected to the amplifier circuit, a current that is substantially a replica of the input signal.

Abstract: Power amplifier modules with controllable envelope tracking noise filters are provided herein. In certain embodiments, an envelope tracking system includes a power amplifier module and an envelope tracker that provides the power amplifier module with a power amplifier supply voltage that changes based on an envelope of a radio frequency (RF) signal amplified by the power amplifier module. The power amplifier module includes a controllable filter that filters the power amplifier supply voltage to provide flexibility in filtering envelope tracking noise.

Abstract: Systems and techniques are described that are directed to filter frequency response shift compensation, including compensating for shifting in the rejection band of the filter. Compensation for the shifting in the rejection band can include applying a pre-distortion to attenuate edge resource units (RUs), and applying PHY Protocol Data Unit (PPDU) scheduling schemes. For example, a PPDU scheduling scheme reduce bandwidth in the channel, thereby dropping the out of band RUs. Front ends provide feedback to a respective radio, which allows that radio to apply the appropriate pre-distortion. The front ends can include one or more filters enabling frequency domain coexistence between collocated radios operating in the differing Wi-Fi bands, and a coupler that provides the feedback indicating the frequency response shift to a radio. The radio can then apply a digital pre-distortion to compensate for the shifting in the rejection band.

Abstract: A baseband chip may include a transmitter configured to transmit a first signal. The baseband chip may also include a receiver configured to receive a second signal that includes a receive signal portion and a harmonic interference portion leaked from the transmitter. The baseband chip may further include a harmonic model block configured to multiply a first output from a first harmonic model associated with an amplitude modulation phase modulation (AMPM) look-up table (LUT) and a second output of a second harmonic model associated with an AMAM LUT to generate a third output. The harmonic model block may be further configured to estimate the harmonic interference portion based at least in part on the third output. The baseband chip may also include an interference cancellation block configured to cancel the harmonic interference portion from the second signal to obtain the receive signal portion.

Abstract: A signal transmission apparatus (1) includes: a distortion compensation unit (11) for performing a distortion compensation processing on an input signal (x) by using a Neural Network (112) including L+1 arithmetic layers that include L (L is a variable number representing an integer equal to or larger than 1) hidden layer (112M) and an output layer (112O); a storage unit (13) for storing parameter sets (131) each of which includes a parameter for Q (Q is a variable number representing an integer equal to or smaller than L) arithmetic layer of the L+1 arithmetic layers; and an application unit (142) for selecting one parameter set from the parameter sets based on a signal pattern of the input signal and applying the parameter included in the selected one parameter set to the M number of arithmetic layer, a parameter of another arithmetic layer of the L+1 arithmetic layers, which is other than the Q arithmetic layer, is fixed.

Abstract: The present disclosure relates to a radio frequency power amplifier system (200) comprising a first (114) and a second input port (121). The radio frequency power amplifier system (200) comprises a main amplifier (101) having an input (107) and an output (108) and a first (102) and a second auxiliary amplifier (122) having respective inputs (109, 129) and outputs (110, 128). The radio frequency power amplifier system (200) comprises an internal load (103) connected to the output (110) of the first auxiliary amplifier (102), a feedback network (104) having an input end (111) connected to the output (110) of the first auxiliary amplifier (102) and an output end (112) connected to the input (109) of the first auxiliary amplifier (102). The radio frequency power amplifier system (200) also comprises a feedforward amplifier (123) having an input (124) and an output (130).

Abstract: A controller is a controller for an adjuster that adjusts an input signal for pre-distortion of an amplifier. The controller includes a determination unit that determines a target section corresponding to electric power of the input signal among set sections and a generator that generates a control signal. The adjuster is configured to adjust at least one of an amplitude and a phase of the input signal. An amount of adjustment of at least one of the amplitude and the phase of the input signal is brought in correspondence with each of the sections. The generator generates a signal indicating the amount of adjustment brought in correspondence with the target section as the control signal and provides the control signal to the adjuster.

Abstract: A method of operating an amplifier circuit having a transformer arranged so as to establish a magnetically coupled feedback loop between and output of an amplifier and an input of the amplifier. The method includes providing a DC bias current to the amplifier, and further includes increasing the DC bias current to improve a linearity of the amplifier circuit wherein a transfer gain of the amplifier circuit remains constant when the DC bias current is increased. A loop gain of the magnetically coupled feedback loop is set by selecting a coupling factor and turn-ratio of the transformer.

Abstract: Systems, devices, and methods related to hybrid basis function, neural network-based digital predistortion (DPD) are provided. An example apparatus for a radio frequency (RF) transceiver includes a digital predistortion (DPD) actuator to receive an input signal associated with a nonlinear component of the RF transceiver and output a predistorted signal. The DPD actuator includes a basis-function-based actuator to perform a first DPD operation using a set of basis functions associated with a first nonlinear characteristic of the nonlinear component. The DPD actuator further includes a neural network-based actuator to perform a second DPD operation using a first neural network associated with a second nonlinear characteristic of the nonlinear component. The predistorted signal is based on a first output signal of the basis-function-based actuator and a second output signal of the neural network-based actuator.

Abstract: Certain aspects of the present disclosure provide techniques for digital pre-distortion (DPD). An apparatus for wireless communication generally includes a power amplifier (PA); a first DPD circuit, a second DPD circuit, and a transmitter. The first DPD circuit is generally configured to: obtain an input signal; apply a first DPD to the input signal to generate a first resulting signal; and output the first resulting signal to the second DPD circuit. The second DPD circuit is generally configured to: obtain the first resulting signal from the first DPD circuit; apply a second DPD to the first resulting signal to generate a second resulting signal; and output the second resulting signal to the PA. The PA is generally configured to amplify the second resulting signal to generate an amplified second resulting signal. The transmitter is generally configured to transmit the amplified second resulting signal to a second apparatus.

Abstract: An operation method of an electronic device includes determining whether a first communication module based on a first radio access technology (RAT) and a second communication module based on a second RAT operate in a connected state; determining whether a combination of a first band used by the first communication module and a second band used by the second communication module is a combination causing interference; and if the combination of the first band and the second band is a combination causing interference, transmitting a signal requesting to change one of the first band or the second band. The interference is caused by at least one transmission signal of the first RAT or at least one other signal derived from the at least one transmission signal.

Abstract: A radio frequency (RF) generator system includes first and second RF power sources, each RF power source applying a respective RF signal and second RF signal to a load. The first RF signal is applied in accordance with the application of the second RF signal. The application of the first RF signal is synchronized to application of the second RF signal. The first RF signal may be amplitude modulated in synchronization with the second RF signal, and the amplitude modulation can include blanking of the first RF signal. A frequency offset may be applied to the first RF signal in synchronization with the second RF signal. A variable actuator associated with the first RF power source may be controlled in accordance with the second RF signal.

Abstract: Apparatus and methods for power amplifier trimming based on coefficients for digital pre-distortion (DPD) are disclosed. In certain embodiments, a mobile device includes a transmit circuit that generates a plurality of digital transmit signals. The transmit circuit includes a plurality of DPD circuits each operable to provide DPD to a corresponding one of the digital transmit signals, a coefficient comparator circuit that generates a trimming control signal based on a plurality of coefficients of the plurality of DPD circuits, and a plurality of digital to radio frequency (RF) converters that convert the digital transmit signals into a plurality of RF signals. The mobile device further includes a front end system including a plurality of power amplifiers each amplifying a respective one of the RF signals, and a power amplifier trimming circuit that controls trimming of the power amplifiers based on the trimming control signal.

Abstract: This application relates to amplifier circuitry, in particular class-D amplifiers, operable in open-loop and closed-loop modes. An amplifier (300) has a forward signal path for receiving an input signal (SIN) and outputting an output signal (SOUT) and a feedback path operable to provide a feedback signal (SFB) from the output. A feedforward path provide a feedforward signal (SFF) from the input and a combiner (105) is operable to determine an error signal (?) based on a difference between the feedback signal and the feedforward signal. The feedforward comprises a compensation module (201) configured to apply a controlled transfer function to the feedforward signal in the closed-loop mode of operation, such that an overall transfer function for the amplifier is substantially the same in the closed-loop mode of operation and the open-loop mode of operation.

Abstract: Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a base station, an indication of a change in a non-linearity model associated with a power amplifier of the base station. The UE may update a model associated with the power amplifier based at least in part on the indication. The UE may further update at least one parameter associated with slicing received signals based at least in part on the indication. In some aspects, the UE may use at least two coefficients when slicing. Numerous other aspects are described.

Abstract: Disclosed are a solid-state microwave source and a branch consistency control method thereof. The branch consistency control method includes: collecting phase information of each branch unit under each of a plurality of preset target powers, and performing phase adjustment for each branch unit based on the phase information under each of the target powers; assembling coarsely-adjusted N branch units, a driver module, a power distribution module, a radial combiner, a circulator, and a waveguide coupler; adjusting a branch power by using the driver module and the power distribution module, to collect the phase information of each branch unit under each of the target powers; and when the phase information of each branch unit under each of the target powers meets a preset condition, performing phase adjustment for the branch unit based on the phase information.

Abstract: An autotuning controller is provided for improving power efficiency and linearity of digital power amplifiers (DPAs). The controller includes an interface including input and output terminals connected to the DPAs, the interface being configured to acquire input signals and output signals, a digital pre-distortion (DPD)-DPA adaptive controller including a processor and a memory running and storing a DPD algorithm, an efficiency enhancement method and a learning cost function.

Abstract: Examples relate to an amplification apparatus, device or method, to a Tap for a cable communication network comprising an amplification apparatus or device, and to a cable communication network comprising an amplification apparatus or device. The amplification apparatus comprises interface circuitry for exchanging a first version of a shared signal with a first component of the cable communication network. The shared signal is based on a frequency spectrum comprising at least a first frequency band and a second frequency band. The amplification apparatus comprises interface circuitry for exchanging a second version of the shared signal with a second component of the cable communication network. The amplification apparatus comprises amplifier circuitry configured to selectively amplify the first frequency band of the frequency spectrum of the shared signal, such that the first frequency band is amplified in the second version of the shared signal.

Abstract: A new radio base station establishes a first and a second component. The first and second component carrier overlap each other. The base station transmits first synchronization signal blocks on the first component carrier. The base station transmits second synchronization signal blocks on the second component carrier interleaved in time with the first synchronization signal blocks.

Abstract: Systems comprising a low power Digital Predistortion (DPD) system and methods of operation thereof are disclosed herein. In some embodiments, a system comprises a DPD system for digitally predistorting an input signal to provide an output signal. The DPD system comprises a DPD actuator comprising one or more configurable multiplication functions, each configurable to operate in different power modes. The different power modes comprise a first power mode in which the configurable multiplication function multiplies a first value related to an input sample of the input signal and a second value related to a respective DPD value to provide an output value and a second power mode in which the configurable multiplication function outputs, as the output value, are an approximation of a multiplication of the first value and the second value.

Abstract: Techniques are disclosed related to determining a modulation quality measurement of a device-under-test (DUT). A modulated signal is received from a source a plurality of times, and each received modulated signal is transmitted to each of a first vector signal analyzer (VSA) and a second VSA. The first VSA and the second VSA demodulate the received modulated signals to produce first error vectors and second error vectors, respectively. A cross-correlation calculation is performed on the first error vectors and second error vectors of respective received modulated signals to produce a complex-valued cross-correlation measurement, and a real component of the cross-correlation measurement is averaged over the plurality of received modulated signals. A modulation quality measurement is determined based on the averaged cross-correlation measurement.

Abstract: A wideband power amplifier (PA) linearization technique is proposed. A current interpolation technique is proposed to linearize power amplifiers over a wide bandwidth. The wideband power amplifier linearization technique employs a novel transconductance Gm linearizer using a current interpolation technique that achieves improvement in the third order intermodulation over wide bandwidth for a sub-micron CMOS differential power amplifier. By using a small amount of compensating bias into an opposite phase differential pair, linearization over wide bandwidth is achieved and can be optimized by adjusting the compensating bias.

Abstract: A power amplifier system includes: a drive stage configured to amplify an RF input signal and implemented in a substrate containing silicon; a power stage including a carrier amplifier configured to amplify a base signal from the RF input signal as amplified by the drive stage, and a peaking amplifier configured to amplify a peak signal from the RF input signal as amplified by the drive stage, the power stage being implemented in a substrate containing gallium arsenide; and a phase compensation circuit configured to change a phase of the RF input signal, wherein either the carrier amplifier or the peaking amplifier is connected to the phase compensation circuit.

Abstract: A distortion compensation device includes: a first distortion compensation circuit having a first distortion compensation characteristic for compensating for a first distortion occurring in an output of an amplifier, the first distortion compensation circuit being configured to compensate for the first distortion; a second distortion compensation circuit having a second distortion compensation characteristic for compensating for a second distortion occurring in the output of the amplifier, the second distortion compensation circuit being configured to compensate for the second distortion; and an update unit configured to update the second distortion compensation characteristic.

Abstract: A sign switching circuitry is disclosed. In one aspect, the sign switching circuitry includes a first and second differential common-source amplifier having common differential input nodes and common differential output nodes configured such that a differential input signal applied at the common differential input nodes is amplified to a differential output signal at the common differential output nodes with a fixed gain by the first amplifier and by the fixed gain with opposite sign by the second amplifier. The sign switching circuitry also includes a switching circuitry configured to activate the first common-source amplifier and deactivate the second common-source amplifier to amplify the differential input signal by the fixed gain, and to activate the second common-source amplifier and deactivate the first common-source amplifier to amplify the differential input signal by the fixed gain with opposite sign.

Abstract: A DPD (1) includes: a polynomial structure including a pseudo-interpolation/sub-sample-shift processing unit (101) configured to operate at a sampling rate for sampling an input signal not upsampled in a previous stage of the DPD (1), pseudo-interpolate a sample point between sample points of the input signal, and shift the pseudo-interpolated sample point by a sub-sample and a multiplexer (109) configured to select a combination of a sub-sample shift amount; and an FIR filter (107) configured to be provided in a subsequent stage of the polynomial structure and include a sub-sample delay filter delaying a sample point of the input signal by a sub-sample. The DPD (1) compensates for distortion due to a sample point of the input signal and compensates for distortion due to a sub-sample point between sample points of the input signal for the DPD (1), by using the polynomial structure and the FIR filter (107).

Abstract: Certain aspects of the present disclosure provide an amplification system. The amplification system generally includes: a first amplifier having an output coupled to an output of the amplification system; a second amplifier, inputs of the first amplifier and the second amplifier being coupled to an input of the amplification system; an impedance coupled to an output of the second amplifier; and a biasing circuit having a first voltage sense input coupled to the output of the first amplifier, a second voltage sense input coupled to the output of the second amplifier, and an output coupled to a bias input of the first amplifier.

Abstract: An electronic device configured to apply, to a first power amplifier (PA) input, one or more updated memory digital pre-distorter (mDPD) coefficient values is provided. The electronic device includes a processor; and a memory including a non-transitory computer readable storage medium storing instructions that, when executed, cause the processor to preload, from values stored in the memory of the electronic device, one or more mDPD coefficient values; transmit a training signal sequence while using the preloaded one or more mDPD coefficient values; receive the training signal sequence; update the one or more mDPD coefficient values based on the transmitted training signal sequence, the received training signal sequence, and the preloaded one or more mDPD coefficient values; and apply the updated one or more mDPD coefficient values to distort the first PA input.

Abstract: Embodiments of a calibration system for third order intermodulation distortion (IMD3) cancellation and a wireless apparatus are disclosed. In an embodiment, a calibration system for IMD3 cancellation includes a cancellation circuit for IMD3 cancellation between a first transmitter and a second transmitter, and a controller coupled to the cancellation circuit and configured to for each frequency channel of the first transmitter, perform a pre-conditional calibration of the cancellation circuit, after the pre-conditional calibration, determine a phase configuration for the cancellation circuit, and after the phase configuration for the cancellation circuit is determined, determine an attenuation configuration for the cancellation circuit.

Abstract: Various embodiments of the present disclosure relate to transmitter systems, methods, and instructions for signal predistortion.