Apparatus including a first transmission line for transmitting radio frequency, RF, signals and at least one RF device including at least one active semiconductor device for processing RF signals, wherein said at least one RF device is coupled to said first transmission line, and wherein said first transmission line includes an electro-chromic, EC, material a permittivity of which can be controlled by applying a first control voltage to said first transmission line.

The present disclosure provides a reconfigurable power amplifier (PA) based on a PIN switch and a design method thereof. The reconfigurable PA based on a PIN switch includes an input port, an input matching circuit, the PIN switch, a gate bias circuit, a transistor, a drain bias circuit, an output matching circuit and an output port, where the input matching network includes an input end connected to a power input end, and an output end connected to a gate of the transistor, the gate bias circuit is connected in parallel with the gate, the drain bias circuit is connected in parallel with a drain, the drain of the transistor is connected to an input end of the output matching circuit, and an output end of the output matching circuit serves as a power output.

A Doherty amplifier includes a divider configured to divide an input signal into two signals, a first amplifier configured to amplify one of the two signals and output the amplified signal to a first node, a second amplifier configured to amplify the other of the two signals and output the amplified signal to a second node, a balun including lumped parameter elements and configured to output a signal obtained by combining the signal output from the first amplifier with the signal output from the second amplifier to a third node, and a path configured to DC-connect the first node to the second node, with the third node therebetween.

A semiconductor device package includes a plurality of input leads and an output lead, a plurality of transistor amplifier dies having inputs respectively coupled to the plurality of input leads, and a combination circuit configured to combine output signals received from the plurality of transistor amplifier dies and output a combined signal to the output lead.

A matching network is a matching network of a power amplifier circuit that outputs a signal obtained by a differential amplifier amplifying power of a high-frequency signal. The matching network includes an input-side winding connected between differential outputs of the differential amplifier; an output-side winding that is coupled to the input-side winding via an electromagnetic field and whose one end is connected to a reference potential; a first LC series resonant circuit including a capacitive element and an inductive element connected in series with each other, and being connected in parallel with the input-side winding; and a second LC series resonant circuit including a capacitive element and an inductive element connected in series with each other, and being connected in parallel with the output-side winding.

Two transistor rows are arranged on or in a substrate. Each of the two transistor rows is configured by a plurality of transistors aligned in a first direction, and the two transistor rows are arranged at an interval in a second direction orthogonal to the first direction. A first wiring is arranged between the two transistor rows when seen from above. The first wiring is connected to collectors or drains of the plurality of transistors in the two transistor rows. The first bump overlaps with the first wiring when seen from above, is arranged between the two transistor rows, and is connected to the first wiring.

Disclosed are a radio-frequency power amplifier, a radio-frequency front-end module and a communication terminal. The radio-frequency power amplifier includes a control unit, a power amplification unit, a detection unit and an input matching unit. In the radio-frequency power amplifier, the detection unit detects an index parameter related to the output power of the power amplification unit in real time, converts the index parameter into a voltage positively correlated to the magnitude of the index parameter, and outputs the voltage to the input matching unit, such that a phase change of a radio-frequency signal input into the power amplification unit is the opposite of a phase change generated by an output signal of the power amplification unit, thereby effectively realizing the compensation of phase distortion of radio-frequency signals output by the power amplification unit in different modes, and improving a linearity index of the radio-frequency front-end module.

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 transceiver includes a first common T-coil circuit coupled to a first input-output pin of the transceiver, a termination impedance coupled to the first common T-coil circuit and configured to match an impedance of a transmission line coupled to the first common T-coil circuit, an amplifier configured to receive an input signal from the first input-output pin through the first common T-coil circuit based on a receive enable signal, and a first transmission buffer configured to transmit an output signal to the first input-output pin through the first common T-coil circuit based on a transmit enable signal.

A radio-frequency module including a module substrate having a first main surface and a second main surface on opposite sides; a low-noise amplifier disposed on the second main surface; and a power amplifier circuit in a Doherty configuration. The power amplifier including a first phase circuit; a second phase circuit; a carrier amplifier disposed on the first main surface and including an input terminal connected to a first end of the first phase circuit and an output terminal connected to a first end of the second phase circuit; and a peaking amplifier disposed on the first main surface and including an input terminal connected to a second end of the first phase circuit and an output terminal connected to a second end of the second phase circuit.