An amplifying device includes a radio frequency (RF) signal input terminal to which an RF signal is input, a buffer circuit, a linearizer including a transistor, a power amplifier, and a control circuit. The control circuit outputs a first gate voltage when a level of the RF signal input is a first level, the first gate voltage causing the transistor to perform a class B operation. The control circuit outputs a second gate voltage when the level of the RF signal is a second level higher than the first level, the second gate voltage causing the transistor to perform a class AB operation. Output impedance of the buffer circuit that is seen from an input side of the linearizer is set such that a reflection loss of the RF signal input from the buffer circuit to the linearizer is a predetermined level or less.

An amplifier includes a semiconductor die and a substrate that is distinct from the semiconductor die. The semiconductor die includes a first RF signal input terminal, a first RF signal output terminal, and a transistor. The transistor has a control terminal electrically coupled to the first RF signal input terminal, and a current-carrying terminal electrically coupled to the first RF signal output terminal. The substrate includes a second RF signal input terminal, a second RF signal output terminal, circuitry coupled between the second RF signal input terminal and the second RF signal output terminal, and an electrostatic discharge (ESD) protection circuit. The amplifier also includes a connection electrically coupled between the ESD protection circuit and the control terminal of the transistor. The substrate may be another semiconductor die (e.g., with a driver transistor and/or impedance matching circuitry) or an integrated passive device.

A Doherty amplifier including a main amplifier and a peak amplifier is mounted on a package substrate. A low noise amplifier is further mounted on the package substrate. A transmit/receive switch switches in terms of time between a transmission connection state in which an output signal of the Doherty amplifier is supplied to an antenna and a reception connection state in which a signal received by the antenna is inputted to the low noise amplifier.

Amplification device and processes capable of miniaturization in a device for performing linear amplification and switching amplification operations on incoming signals are provided. The amplifying device includes a first amplifying unit for amplifying an input signal and outputting a first output signal, the input switch unit connected in parallel with the first amplifying unit for performing a switching operation by an input signal and outputting a switch output signal, and a second amplifying unit for amplifying a first output signal or a switch output signal and outputting a second output signal, and the first amplifying unit or the input switch unit operates based on the type of the input signal.

A digital power amplifier comprising at least two individually activatable amplifiers connected to an output network comprising a first hybrid coupler. An output of a first amplifier is connected to a first input of the first hybrid coupler and an output of a second amplifier is connected to a second input of the first hybrid coupler such that activating an amplifier of the at least two amplifiers causes the amplifier to load modulate another activated amplifier of at least two amplifiers.

RF transistor amplifiers include an RF transistor amplifier die having a semiconductor layer structure, a coupling element on an upper surface of the semiconductor layer structure, and an interconnect structure on an upper surface of the coupling element so that the RF transistor amplifier die and the interconnect structure are in a stacked arrangement. The coupling element includes a first shielded transmission line structure.

An LNA having a plurality of paths, each of which can be controlled independently to achieve a gain mode. Each path includes at least an input FET and an output FET coupled in series. A gate of the output FET is controlled to set the gain of the LNA. Signals to be amplified are applied to the gate of the input FET. Additional stacked FETs are provided in series between the input FET and the output FET.

A system includes a first differential amplifier and a first transformer with a primary coil coupled to an output of the first differential amplifier and with a secondary coil coupled to a load. The system also includes a second differential amplifier and a second transformer with a primary coil coupled to an output of the second differential amplifier and with a secondary coil coupled in series with the secondary coil of the first transformer. The system also includes a tuning network coupled to a center tap node between the secondary coil of the first transformer and the secondary coil of the second transformer.

A power amplifier circuit includes power amplifiers connected in stages to amplify a high-frequency input signal and to output an amplified high-frequency output signal, bias circuits each of which outputs a bias current to a corresponding one of the power amplifiers, and a bias control circuit configured to output a bias control current based on a second reference potential that varies in response to power of the high-frequency output signal and that is a potential of a portion in one bias circuit of the bias circuits to one or more bias circuits in a stage preceding the one bias circuit for increasing a bias current outputted from the one or more bias circuits in the stage preceding the one bias circuit.

Power amplifier (PA) packages, such as Doherty PA packages, containing multi-path integrated passive devices (IPDs) are disclosed. In embodiments, the PA package includes a package body through which first and second signal amplification paths extend, a first amplifier die within the package body and positioned in the first signal amplification path, and a second amplifier die within the package body and positioned in the second signal amplification path. A multi-path IPD is further contained in the package body. The multi-path IPD includes a first IPD region through which the first signal amplification path extends, a second IPD region through which the second signal amplification path extends, and an isolation region formed in the IPD substrate a location intermediate the first IPD region and the second IPD region.