The present disclosure facilitates impedance matching between a power amplifier and filters. A radio-frequency circuit includes a power amplifier, a plurality of transmit filters, a switch, a plurality of first matching networks, and a second matching network. The switch switches the plurality of transmit filters to be coupled to the power amplifier. The plurality of first matching networks are coupled between the plurality of transmit filters and the switch. The second matching network is coupled between the power amplifier and the switch. The second matching network includes a transmission line transformer.

An amplification device includes an amplification unit, an impedance unit and a log power detector. The amplification unit includes an input terminal for receiving a radio-frequency signal, an output terminal for outputting an amplified radio-frequency signal, and a detected terminal for outputting a detected signal related to the radio-frequency signal. The impedance unit is used to provide an impedance. The impedance unit includes an input terminal coupled to the detected terminal of the amplification unit for receiving the detected signal, and an output terminal for outputting a power signal. The log power detector is used to generate a power indication signal according to the power signal. The log power detector includes an input terminal coupled to the output terminal of the impedance unit, and an output terminal for outputting the power indication signal.

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 monolithic integrated circuit (IC), and method of manufacturing same, that includes all RF front end or transceiver elements for a portable communication device, including a power amplifier (PA), a matching, coupling and filtering network, and an antenna switch to couple the conditioned PA signal to an antenna. An output signal sensor senses at least a voltage amplitude of the signal switched by the antenna switch, and signals a PA control circuit to limit PA output power in response to excessive values of sensed output. Stacks of multiple FETs in series to operate as a switching device may be used for implementation of the RF front end, and the method and apparatus of such stacks are claimed as subcombinations. An iClass PA architecture is described that dissipatively terminates unwanted harmonics of the PA output signal. A preferred embodiment of the RF transceiver IC includes two distinct PA circuits, two distinct receive signal amplifier circuits, and a four-way antenna switch to selectably couple a single antenna connection to any one of the four circuits.

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 power amplifier circuit includes a first power supply terminal electrically connected to a first power amplifier; a second power supply terminal electrically connected to a second power amplifier subsequent to the first power amplifier; a first external power supply line configured to electrically connect a power supply circuit configured to output a power supply potential corresponding to an amplitude level of a high-frequency input signal and the first power supply terminal; and a second external power supply line configured to electrically connect the power supply circuit and the second power supply terminal. An inductance value of the first external power supply line is higher than an inductance value of the second external power supply line.

An apparatus includes a near-field probe having loops or coils of electrically-conductive material, where the near-field probe is configured to generate a magnetic field. The apparatus also includes a power amplifier configured to drive the near-field probe. The apparatus further includes a shunt capacitance coupled in parallel across the loops or coils of the near-field probe. The shunt capacitance and an inductance of the loops or coils of the near-field probe form part of a resistive-inductive-capacitive (RLC) network. The RLC network is configured to transform a smaller resistance of the near-field probe into a larger resistance. In some cases, the apparatus may include multiple near-field probes coupled in series, and the power amplifier may be configured to drive the multiple near-field probes. For each near-field probe, the apparatus may include a shunt capacitance coupled in parallel across the loops or coils of the near-field probe.

A packaged radio frequency transistor amplifier includes a package housing, an RF transistor amplifier die that is mounted within the package housing, a first capacitor die that is mounted within the package housing, an input leadframe that extends through the package housing to electrically connect to a gate terminal of the RF transistor amplifier die, and an output leadframe that extends through the package housing to electrically connect to a drain terminal of the RF transistor amplifier die. The output leadframe includes an output pad region, an output lead that extends outside of the package housing, and a first arm that extends from one of the output pad region and the output lead to be adjacent the first capacitor die.

A device that includes a substrate and a power amplifier coupled to the substrate. The substrate includes at least one dielectric layer, a plurality of interconnects, and a capacitor configured to operate as an output match element, where the capacitor is defined by a plurality of capacitor interconnects. The power amplifier is coupled to the capacitor. The capacitor is configured to operate as an output match element for the power amplifier. The substrate includes an inductor coupled to the capacitor, where the inductor is defined by at least one inductor interconnect. The capacitor and the inductor are configured to operate as a resonant trap or an output match element.