A semiconductor device includes a semiconductor substrate including a principal surface parallel to a plane defined by a first direction and a second direction substantially orthogonal to the first direction, and the principal surface having a first side parallel to the first direction; first unit transistors, each amplifying a first signal in a first frequency band to output a second signal; and second unit transistors, each amplifying the second signal to output a third signal and aligned in the second direction between the first side and a substrate center line in the first direction in plan view of the principal surface. A first center line in the first direction of a region in which the first unit transistors are aligned is farther from the first side than a second center line in the first direction of a region in which the second unit transistors are aligned.

Techniques (implemented in circuit arrangements, methods, computer instructions) are disclosed which permit digital pre-distortion for amplifiers. A common signal source provides a common analog signal from a digital input signal; a plurality of amplifiers amplifies a split signal which is a split version of the common analog signal; a built-in test circuit is configured to provide distortion information associated to distortion affecting the amplifier. The common signal source implements a signal conditioner to perform, in a signal path of the digital input signal, a feed-forward pre-distortion of the digital input signal according to a pre-distortion relationship mapping the digital input signal onto a pre-distorted version. The signal conditioner is configured to adjust the pre-distortion relationship in dependence on the distortion information.

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 digital power amplifier comprising two or more individually activatable amplifiers. The outputs of the amplifiers are connected causing an activated amplifier of the two or more amplifiers to load modulate another activated amplifier of the two or more amplifiers.

An XTC circuit includes delay circuits, differentiated signal generating circuits, and an amplitude adjusting and adding circuit. A signal Da, which is one aggressor signal, is input to the differentiated signal generating circuit after being delayed by the delay circuit, and the differentiated signal generating circuit generates a differentiated signal having a differentiated waveform of the signal Da. In the amplitude adjusting and adding circuit, the differentiated signal generated by the differentiated signal generating circuit is amplitude-adjusted to become a current signal, and the differentiated signal after the amplitude adjustment is current-added to the signal Db.

A radio-frequency power converter and a radio-frequency transmission system for magnetic resonance imaging are provided in embodiments of the present invention. The radio-frequency power converter comprises a printed circuit board, the printed circuit board comprises a first circuit layer, a ground layer, and one or a plurality of intermediate layers located between the first circuit layer and the ground layer. A plurality of planar spiral inductors connected in parallel are formed on the first circuit layer. One ends of the plurality of inductors are connected to each other and respectively connected to one end of a first capacitor, the other ends of the plurality of inductors are respectively connected to one ends of a plurality of second capacitors, and the other ends of the plurality of second capacitors are all grounded.

Methods and devices addressing design of reconfigurable wideband LNAs to meet stringent gain, noise figure, and linearity requirements with multiple gain modes are disclosed. The disclosed teachings can be used to reconfigure RF receiver front-end to operate in various applications imposing stringent and conflicting requirements, such as 5G NR radios. Wideband and narrowband input and output matching with gain modes using a combination of the same hardware and a switching network are also disclosed.

A communication circuit, including a first supply modulator configured to provide a first supply voltage; a first power amplifier configured to generate a first output signal by amplifying a first input signal corresponding to a first operation frequency band, a second power amplifier configured to generate a second output signal by amplifying a second input signal corresponding to a second operation frequency band; and a switching circuit configured to selectively provide the first supply voltage from the first supply modulator to the second power amplifier based on a first switching signal according to an operation node.

An electrically conductive sub-collector layer is provided in a surface layer portion of a substrate. A collector layer, a base layer, and an emitter layer are located within the sub-collector layer when viewed in plan. The collector layer is connected to the sub-collector layer. An emitter electrode and a base electrode are long in a first direction when viewed in plan. The emitter electrode overlaps the emitter layer. The base electrode and the emitter electrode are discretely located away from each other in a second direction orthogonal to the first direction. A collector electrode is located on one side in the second direction with respect to the emitter electrode and is not located on the other side when viewed in plan. A base line is connected to the base electrode in a manner so as to adjoin a portion other than longitudinal ends of the base electrode.

An envelope stacking power amplifier system reduces current for a given output power level without sacrificing the ability to support large voltage swings at saturation and therefore increases efficiency at the maximum linear operating power and all power levels below that. The system includes a stack/unstack controller including circuitry configured to switch the RF power amplifier system between a stacked mode in which first and second RF amplifiers are coupled in a stacked configuration and an unstacked mode in which the first and second RF amplifiers are coupled in an unstacked configuration in response to one or more mode-control signals, the stacked configuration providing reduced current compared to the unstacked configuration.