A low noise amplifier may include a post distortion cancellation block coupled to the low noise amplifier. The post distortion cancellation block may include a diode, and phase-shift logic. The phase-shift logic may be coupled in series with the diode.

Apparatus and methods for biasing of power amplifiers are disclosed. In one embodiment, a mobile device includes a transceiver that generates a radio frequency signal and a power amplifier enable signal, a power amplifier that provides amplification to the radio frequency signal and that is biased by a bias signal, and a bias circuit that receives the power amplifier enable signal and generates the bias signal. The bias circuit includes a gain correction circuit that generates a correction current in response to activation of the power amplifier enable signal, and a primary biasing circuit that generates the bias signal based on the correction current and the power amplifier enable signal.

A power amplifier includes a two-dimensional matrix of NM active cells formed by stacking main terminals of multiple active cells in series. The stacks are coupled in parallel to form the two-dimensional matrix. The power amplifier includes a driver structure to coordinate the driving of the active cells so that the effective output power of the two-dimensional matrix is approximately NM the output power of each of the active cells.

An amplifier includes an amplifying device and a bias circuit for providing a bias voltage for the amplifying device. The bias circuit is configured to provide the bias voltage in dependence of an output signal of an optical coupling arrangement which provides for electrical isolation.

An operational amplifier includes: a first amplifier stage, configured to generate first output voltages according to first input voltages; a second amplifier stage, configured to generate second output voltages according to the first output voltages; a second output stage circuit, configured to replicate an equivalent or a scaled-down version of the first output stage circuit; a first common-mode feedback circuit, configured to keep an output common-mode voltage of the second output stage circuit at a predetermined value; a logic loop circuit configured to, when the operational amplifier operates in a direct current calibration phase, adjust a difference between the first output voltages; a bias circuit, configured to generate a voltage close to a common mode voltage of the first output voltages produced after the operational amplifier is turned on, the voltage serving as a reference voltage of a second common-mode feedback circuit.

A power amplifier module includes a first substrate and a second substrate, at least part of the second substrate being disposed in a region overlapping the first substrate. The second substrate includes a first amplifier circuit and a second amplifier circuit. The first substrate includes a first transformer including a primary winding having a first end and a second end and a secondary winding having a first end and a second end; a second transformer including a primary winding having a first end and a second end and a secondary winding having a first end and a second end; and multiple first conductors disposed in a row between the first transformer and the second transformer, each of the multiple first conductors extending from the wiring layer on a first main surface to the wiring layer on a second main surface of the substrate.

A high frequency module includes a transmission power amplifier, a bump electrode connected to the transmission power amplifier, and a mounting board on which the transmission power amplifier is mounted, wherein the mounting board includes a via conductor having an elongated shape in the plan view of the mounting board, a board main part placed outside the via conductor, and an insulating part placed inside the via conductor, and the bump electrode and the via conductor are connected while at least partially overlapping each other in the foregoing plan view, and the board main part and the insulating part are each composed of an insulating material of the same kind.

A radio-frequency module includes: a transmission power amplifier that includes first and second amplification transistors that are cascade connected to each other; and a mounting substrate that has first and second main surface that face each other, the transmission power amplifier being mounted on the first main surface. The first amplification transistor is arranged in a final stage and has a first emitter terminal. The second amplification transistor is arranged in a stage preceding the first amplification transistor and has a second emitter terminal. The mounting substrate has first to fourth ground electrode layers in order of proximity to the first main surface. The first emitter terminal and the second emitter terminal are not electrically connected to each other via an electrode on the first main surface and are not electrically connected to each other via the first ground electrode layer.

A radio frequency (RF) power combining amplifier circuit has a circuit input and a circuit output. A first amplifier is connected to the circuit input and to a first bias input. A first output matching network is connected to an output of the first amplifier and to the circuit output. A second amplifier is connected to the circuit input and to a second bias input. A second output matching network is connected to an output of the second amplifier, and to the circuit output. A voltage level of an input signal applied to the circuit input, together with the respective first bias input and the second bias input, selectively activates the first amplifier and the second amplifier.

Examples disclosed herein relate to a dynamic supply modulation power amplifier architecture for millimeter wave applications. The architecture includes phase shifters coupled to a power input port, power amplifiers coupled to respective power output ports, variable gain amplifiers coupled to the phase shifters and to the power amplifiers and are configured to supply dynamically varying input power to the power amplifiers. The architecture includes a first look-up table coupled to the variable gain amplifiers to control the variable gain amplifiers. The architecture also includes a second look-up table coupled to the power amplifiers, where each of the power amplifiers is supply modulated by active drain voltage modulation controlled by the second look-up table and variable input power from the variable gain amplifiers. Other examples disclosed herein include a radar system for use in an autonomous driving vehicle and an analog beamforming antenna for millimeter wave applications.