A circuit includes a field effect transistor (FET), a reference transistor having an output coupled to an output of the FET, an active bias circuit coupled to the reference transistor and configured to generate an input signal for the reference transistor in response to a change in drain current of the reference transistor due to carrier trapping and to apply the input signal to an input of the reference transistor, and a summing node coupled to an input of the FET and to the input of the reference transistor. The summing node adds the input signal to an input signal of the FET to compensate the carrier trapping effect.

An amplifier includes an input matching network; at least one transistor; an input lead coupled to the at least one transistor; a ground terminal coupled to the transistor; an output lead coupled to the at least one transistor; an output matching circuit coupled to the output lead and to the at least one transistor; and a baseband impedance enhancement circuit having at least one reactive element coupled to the input matching network. The baseband impedance enhancement circuit is configured to reduce resonances of a baseband termination.

A Doherty amplifier includes a peaking amplifier, a carrier amplifier, and a combining node electrically connected to the carrier amplifier and the peaking amplifier. The Doherty amplifier includes a harmonic control circuit coupled to the combining node. The harmonic control circuit includes an inductor and a capacitor and the inductor and capacitor are connected in series between the first current conducting terminal and a ground reference node. An inductance value of the inductor of the harmonic control circuit and a capacitance value of the capacitor of the harmonic control circuit are selected to terminate second order harmonic components of a fundamental frequency of a signal generated by the carrier amplifier.

A multiple-path amplifier (e.g., a Doherty amplifier) includes first and second transistors (e.g., main and peaking transistors) with first and second output terminals, respectively, all of which is integrally-formed with a semiconductor die. A signal path through the second transistor extends in a direction from a control terminal of the second transistor to the second output terminal, where the second output terminal corresponds to or is closely electrically coupled to a combining node. The amplifier also includes an integrated phase delay circuit that is configured to apply an overall phase delay (e.g., 90 degrees) to a signal carried between the first and second output terminals. The integrated phase delay circuit includes delay circuit wirebonds coupled between the first and second output terminals, and the delay circuit wirebonds extend in a third direction that is angularly offset from (e.g., perpendicular to) the second direction.

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.

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.

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 transistor module assembly includes a longitudinally extending load bus bar, a longitudinally extending feed bus bar parallel to the load bus bar, and at least one transistor package operatively connected to the load and feed bus bars. The transistor package includes a drain surface and a source lead. The drain surface is operatively connected to the feed bus bar for receiving current therefrom. The source lead is operatively connected to the load bus bar for dissipating current from the transistor package to the load bus bar.

In many examples, a device comprises a transmitter. The transmitter comprises a power amplifier, a first transformer coil coupled to the power amplifier, and a second transformer coil adapted to be electromagnetically coupled to the first transformer coil. The transmitter also comprises a first bond wire coupled to a first end of the second transformer coil and adapted to be coupled to a first end of an antenna, a capacitor coupled to a second end of the second transformer coil, a switch coupled to the capacitor and configured to engage and disengage the capacitor from the transmitter, and a second bond wire coupled to the switch and adapted to be coupled to a second end of the antenna.

A transistor includes first and second sets of gate fingers formed in an active area of a semiconductor substrate, an input bond pad formed in the semiconductor substrate and spaced apart from the active area, a first conductive structure with a proximal end coupled to the input bond pad and a distal end coupled to the first set of gate fingers, and a second conductive structure with a proximal end coupled to the input bond pad and a distal end coupled to the second set of gate fingers. A non-conductive gap is present between the distal ends of the first and second conductive structures. The transistor further includes an odd-mode oscillation stabilization circuit that includes a first resistor with a first terminal coupled to the distal end of the first conductive structure, and a second terminal coupled to the distal end of the second conductive structure.