An apparatus is disclosed, comprising means for providing two or more amplifiers for amplifying signals in two or more respective frequency bands, receiving a composite signal comprising first and second predistorted input signals in first and second frequency bands and filtering the composite signal to provide (i) the first predistorted signal for input to a first amplifier of the two or more amplifiers for producing an amplified first output signal and (ii) the second predistorted signal for input to a second amplifier of the two or more amplifiers for producing an amplified second output signal. The apparatus may also comprise means for routing, at non-overlapping times, the first and second output signals to a common feedback path and for linearizing received first and second input signals based on the respective first and second output signals received on the common feedback path.

A semiconductor chip includes a first wireless communication circuit, a local oscillator (LO) buffer, and an auxiliary path. The first wireless communication circuit has a signal path, wherein the signal path has a mixer input port and a signal node distinct from the mixer input port. The auxiliary path is used to electrically connect the LO buffer to the signal node of the signal path. The LO buffer is reused for a loop-back test function through the auxiliary path.

An apparatus including a signal generation circuitry to provide a stream of digital signals carrying data. The apparatus includes a storage circuitry to provide a plurality of transmit levels corresponding to respective predetermined equalization levels; selection circuitry to select a transmit level from among the plurality of transmit levels based on the digital signals carrying data. Each of the plurality of transmit levels is a respective input signal to the selection circuitry. The apparatus includes a digital-to-analog converter (DAC) circuitry configured to receive the selected transmit level and convert the selected transmit level to an analog signal of the selected transmit level.

A method for modelling a power amplifier, including memory effect modelling, for general input waveforms and power levels involves generating an extraction waveform having a plurality of tones each having a different frequency, a difference between the frequencies of two adjacent tones of the plurality of tones not being an integer multiple of a difference in frequency between any two other adjacent tones of the plurality of tones. The method further involves providing the extraction waveform to the power amplifier, receiving output from the power amplifier generated in response to the extraction waveform, and generating a model of the power amplifier based on the output.

An electronic device according to various embodiments of the present invention can comprise: a housing; a first antenna element positioned inside the housing or at a first position thereof; a second antenna element positioned inside the housing or at a second position separated from the first position thereof; and a wireless communication circuit positioned inside the housing and electrically coupled to the first antenna element and the second antenna element. The wireless communication circuit comprises: a wireless modem; a source RF circuit electrically connected to the wireless modem, and configured to generate an IF signal; and a second RF circuit positioned at a fourth position closer to the second position than to the first position, wherein: each of the first RF circuit and the second RF circuit is configured to alternately receive an IF signal for transmitting a transmitted signal via the first antenna element and the second antenna element, and includes a first electrical path between the source RF circuit and the second RF circuit, a second electrical path between the source RF circuit and the second RF circuit, and a third electrical path between the first RF circuit and the second RF circuit; the first RF circuit, while being electrically blocked from the first antenna element, is configured to form at least a portion of a first loopback path from the first RF circuit to the source RF circuit through the third electrical path and the second electrical path; and the second RF circuit, while being electrically blocked from the second antenna element, can be configured to form at least a portion of a second loopback path from the second RF circuit to the source RF circuit through the third electrical path and the first electrical path. Additional other embodiments are also possible.

An antenna module includes a power supply element and a ground electrode (GND) arranged so as to face the power supply element. In a plan view of the antenna module from a normal direction, when a minimum distance along the first direction between a center of the power supply element and an end portion of the ground electrode (GND) is defined as a first distance, a minimum distance between the center of the power supply element and an end portion of the ground electrode (GND) is defined as a second distance, and a distance between the end portion of the ground electrode (GND) and an end portion of the power supply element in the second distance is defined as a third distance, the first distance is longer than the second distance, and the third distance is shorter than ½ of a size of the power supply element.

Systems and methods for operating a communication device. The methods comprise: obtaining a signal; allowing the signal to pass through a junction of a communication path to which a reflective frequency selective limiter is coupled; attenuating unwanted components of the signal using the reflective frequency selective limiter; and reflecting remaining components of the signal by the reflective frequency selective limiter so that the remaining components travel downstream along the communication path.

A circuitry includes a first to fourth waveform synthesizers, each waveform synthesizer includes a first terminal and a second terminal to which input signals are input and a third terminal from which an output signal obtained by synthesizing the input signals is output. Frequencies of first to fourth input signals input to each waveform synthesizer are equal to each other, and phases of the second to fourth input signals are values delayed by approximately 180 degrees, delayed by approximately 90 degrees, and delayed by approximately 270 degrees, with respect to a phase of the first input signal. The output signal of each waveform synthesizer transitions from one state to the other state and transitions from the other state to the one state.

A multi-transmission power management circuit is provided. In embodiments disclosed herein, the multi-transmission power management circuit includes multiple quadrature power amplifier circuits each configured to concurrently generate multiple amplified radio frequency (RF) signals based on a respective modulated voltage(s). The multi-transmission power management circuit also includes an envelope tracking (ET) integrated circuit (ETIC) configured to concurrently generate multiple modulated voltages. A control circuit is configured to determine one or more of the multiple quadrature power amplifier circuits that are involved in a multi-transmission scheme. Accordingly, the control circuit can cause the ETIC to provide one or more of the multiple modulated voltages to each of the quadrature power amplifier circuits involved in the multi-transmission scheme. In this regard, the multi-transmission power management circuit can be flexibly configured to support different multi-transmission schemes.

A radio frequency circuit includes a radio frequency front-end module, a switch module and an antenna module. The radio frequency front-end module includes a radio frequency transceiver and a first processing module connected to the radio frequency transceiver, the antenna module includes an antenna for receiving or transmitting a radio frequency signal, and the first processing module is configured to transmit a signal of a first network and a signal of a second network.