Polyphase power amplifiers for load insensitivity are disclosed. In certain embodiments, a polyphase transmit system includes an intermediate frequency transceiver including a first complex mixer that outputs a plurality of intermediate frequency transmit signals of different phases, and an intermediate frequency to radio frequency module including a second complex mixer that generates a plurality of radio frequency transmit signals of different phases based on the plurality of intermediate frequency transmit signals, and a polyphase power amplifier that receives the plurality of radio frequency transmit signals and outputs an amplified radio frequency signal. The polyphase transmit system further includes an antenna that transmits the amplified radio frequency signal.

Method and radio node (500) for controlling a change of communication mode between transmit mode and receive mode according to a Time Division Duplex, TDD, scheme. The radio node has at least two parallel branches (504, 06) for transmission and reception of radio signals, wherein the branches currently operate in a first communication mode. The radio node obtains one or more indication signals (S1A, S1B) generated by one or more of the branches to indicate that the first mode has been turned off. When it is determined that the first communication mode has not been turned off in a faulty branch, e.g. by not receiving an indication signal in time from that branch, the first mode is disabled in the faulty branch, and/or the faulty branch is reported to a supervision center (510). Thereby, it can be discovered when one of the branches is misaligned or otherwise faulty and suitable actions can be taken for repairing or replacing the faulty branch.

A multi-band power amplifier module includes at least one transmission input terminal, at least one power amplifier circuit that receives a first transmission signal and a second transmission signal through the at least one transmission input terminal, a first filter circuit that allows the first transmission signal to pass therethrough, a second filter circuit that allows the second transmission signal to pass therethrough, at least one transmission output terminal through which the first and second transmission signals output from the first and second filter circuits are output, a transmission output switch that outputs each of the first and second transmission signals output from the at least one power amplifier circuit to the first filter circuit or the second filter circuit, and a first tuning circuit that adjusts impedance matching between the at least one power amplifier circuit and the at least one transmission output terminal.

A wireless communication device includes: a plurality of power amplifiers provided for a plurality of respective antenna elements, each of the power amplifiers amplifying a signal; a distortion compensation unit that executes distortion compensation of a transmission signal by using an inverse function corresponding to nonlinear distortion generated in the power amplifiers; and a controller that operates by switching a first mode and a second mode, the first mode setting individual inverse functions for the respective power amplifiers in the distortion compensation unit and updating coefficients of the individual inverse functions, the second mode suspending the update of the coefficients of the individual inverse functions and setting, in the distortion compensation unit, an integrated inverse function acquired by performing weighted addition of the individual inverse functions.

An example transmitter includes first and second circuit stages and interface circuits. The first circuit stage is configured to generate modulated signals each having a different carrier frequency from baseband signals. The second circuit stage is configured to generate radio frequency (RF) energy to be radiated by antenna(s). The interface circuits are coupled between the first circuit stage and the second circuit stage. The second circuit stage and the interface circuits are configurable to provide a first mode and a second mode. In the first mode, the second circuit stage provides transmit paths and the interface circuits couple each of the modulated signals to a respective one of the transmit paths. In the second mode, the second circuit stage provides a first transmit path and the interface circuits couple a sum of at least two of the modulated signals to the first transmit path.

An example electronic device may include a switch configured to perform switching using at least two bias voltages input from a plurality of power suppliers as an input thereto and one of the two bias voltages as an output therefrom; and a first power amplifier which is included in at least one first transmission chain capable of selectively supporting the heterogeneous network among a plurality of transmission chains, and which is configured to amplify a radio frequency signal for transmission based on the bias voltage supplied from the switch.

A DAC-based transmit driver architecture with improved bandwidth and techniques for driving data using such an architecture. One example transmit driver circuit generally includes an output node and a plurality of digital-to-analog converter (DAC) slices. Each DAC slice has an output coupled to the output node of the transmit driver circuit and includes a bias transistor having a drain coupled to the output of the DAC slice and a multiplexer having a plurality of inputs and an output coupled to a source of the bias transistor.

A detection calibration circuit includes a first distributor distributing a high frequency input signal, an amplifier amplifying the first high frequency output signal of the first distributor, a second distributor distributing the amplified first high frequency output signal of the first distributor, a reference signal generator outputting a reference signal in accordance with a switchable reference voltage, a switcher selecting a third high frequency output signal of the second distributor or a reference signal of the reference signal generator and outputting the selected signal, a detector detecting the third high frequency output signal of the second distributor or the reference signal of the reference signal generator from the switcher, a sensitivity switcher adjusting a sensitivity for an output signal of the detector, and a calibration control circuit adjusting a detection gain of an input signal of the detector and an input-output sensitivity for an output signal of the detector.

A digital microwave radio system includes a splitter that splits a common baseband input into two baseband outputs, first and second transmitters, each transmitter electrically connected to a baseband output of the splitter via a mixer, a common local oscillator electrically connected to the mixer of the first transmitter and the mixer of the second transmitter via an adjustable phase shifter, respectively, and a combiner. The common local oscillator is configured to up-convert each baseband output into a radio-frequency signal using a corresponding mixer. The combiner combines the two radio-frequency signals into a 0-degree phase-shift output and a 180-degree phase-shift output, respectively. A phase error control loop adjusts the phase shifter to minimize the 180-degree phase-shift radio-frequency output. A combiner gain control loop adjusts the output power level of the two transmitters in accordance with an actual power detector reading at the 0-degree phase-shift radio-frequency output.

A 5th generation (5G) or pre-5G communication system for supporting a higher data rate than previous 4th generation (4G) communication systems is provided. A switching circuit in a wireless communication system is provided. The switching circuit includes a first coil, a second coil electrically coupled to the first coil, a first switch electrically connected to the second coil, a third coil electrically coupled to the first coil, a second switch electrically connected to the third coil, and a control unit configured to control the opening or closing of the first switch and the second switch. The control unit can be configured to close the first switch and open the second switch to form a first path using the first coil and the second coil, and open the first switch and close the second switch to form a second path using the first coil and the third coil.