A power amplifier system front end measures both forward and reverse power associated with an RF transmit signal. A processor is configured to use measurements derived from the measured forward and reverse power output to adjust the RF transmit signal in order to compensate for one or more memory effects of the power amplifier system.

A method for realizing predistortion compensation processing for 5G NR in-band modulated signals includes configuring the modulator to output a continuous wave signal, switch the output frequency interval of the signal to be consistent with the 5G NR subcarrier bandwidth, and record the power value P0 corresponding to the current frequency through the power meter. The power measurement difference between all points and P0 is calculated and performs normalization, and generates a compensated channel impulse response after shaping filtering; converts it into a power compensation factor in the time domain; performs inverse Fourier transform to generate I and Q baseband signals; generates compensated baseband data; the generated baseband data is filtered, and an analog zero intermediate frequency signal is generated, which is input to the broadband demodulator for frequency conversion modulation of the 5G NR broadband signal. The method operates without the need to modify the device circuit in the channel.

Front end systems and related devices, integrated circuits, modules, and methods are disclosed. One such front end system includes a low noise amplifier in a receive path and a multi-mode power amplifier circuit in a transmit path. An overload protection circuit can adjust an impedance of a switch coupled to the low noise amplifier based on a signal level of the low noise amplifier. The multi-mode power amplifier circuit includes a stacked output stage including a transistor stack of two or more transistors. The multi-mode power amplifier circuit also includes a bias circuit configured to control a bias of at least one transistor of the transistor stack based on a mode of the multi-mode power amplifier circuit. Other embodiments of front end systems are disclosed, along with related devices, integrated circuits, modules, methods, and components thereof.

A transmitter comprises an antenna array demultiplexor having a first input for an output signal, a second input for a control signal, a first output coupled to a first output pin, and a second output coupled to a second output pin. The antenna array demultiplexor provides the output signal to the first or second output based on the control signal. The first and second output pins are coupled to first and second antennae, respectively. In some implementations, the transmitter includes a transformer and a capacitor coupled in parallel between the first and second output pins, and the antenna array demultiplexor comprises a first switch coupled between the first output pin and a first ground pin, and a second switch coupled between the second output pin and a second ground pin. The first switch receives a second control signal, and the second switch receives an inverse of the second control signal.

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.

Embodiments of the present disclosure are directed to an antenna system and a mobile terminal. The antenna system includes a metal antenna, a radio frequency module, and an antenna tuning switch. The mobile terminal includes the antenna system mentioned above. An embodiment of the present disclosure is capable of improving the stability of sensor detection and prevent the whole machine from being in a state of power reduction for a long time, resulting in signal deterioration.

An integrated circuit includes a filter circuit and a computation circuit that applies emphasis to a data stream in a frequency domain to reduce distortion to the data stream caused by the filter circuit. The emphasis is determined based on the distortion caused by the filter circuit. A circuit design system includes logic synthesis and optimization tools that relax parameters for a first filter circuit to generate relaxed parameters, use the relaxed parameters to generate a second filter circuit that filters data, generate an emphasis vector based on distortion in the data caused by the second filter circuit, and generate a computation circuit that applies the emphasis vector to the data to reduce the distortion in the data caused by the second filter circuit.

A radio receiver system and a radio transmitter system are disclosed. The radio receiver system comprises a plurality of intermediate frequency (IF) shifting channels configured to shift incoming signals having a first frequency to an intermediate frequency in a first mixing stage, and to a second frequency in a second mixing stage. The radio transmitter system comprises a plurality of IF shifting channels configured to shift outgoing signals having a first frequency to an intermediate frequency in a first mixing stage, and to a second frequency in a second mixing stage. Since each intermediate frequency is different, the signals shifted to the second frequency combine by coherent addition, and any spurious signals combine by incoherent addition.

Techniques for wireless communications are described. A communication device may support processing digital post distortion using additional references symbols. For example, the communication device may precode a signal including at least two reference symbols for a single-layer transmission using at least two antenna ports. At least one reference symbol of the at least two reference symbols is associated with at least one data symbol of a data stream. The communication device may estimate, based on the at least two reference symbols, a nonlinearity model of at least two power amplifiers associated with the single-layer transmission, and determine an estimate of a nonlinearity factor of the precoded signal based on the estimated nonlinearity model. As a result, the communication device may eliminate or reduce the nonlinear factor of the precoded signal based on the estimated nonlinearity model of the at least two power amplifiers and the estimated channel impulse response.

A radio frequency module includes: a module board including first and second principal surfaces; first and second power amplifiers on the first principal surface; external-connection terminals on the second principal surface; and first and second via conductors connecting the first and second principal surfaces. The first and second via conductors are spaced apart in the module board, one end of the first via conductor is connected to a first ground electrode of the first power amplifier, the other end of the first via conductor is connected to a first external-connection terminal, one end of the second via conductor is connected to a second ground electrode of the second power amplifier, the other end of the second via conductor is connected to a second external-connection terminal, and the first and second via conductors each penetrate through the module board in a direction normal to the first and second principal surfaces.