An amplifier circuit is configured in such a way that the amplifier circuit includes: a first amplifier to amplify a signal to be amplified; an output matching circuit through which the signal amplified by the first amplifier propagates; and a second amplifier to amplify the signal which has propagated through the output matching circuit, and the output matching circuit is a lumped constant circuit including multiple lumped constant elements, and, by using the multiple lumped constant elements, transforms the impedance seen on the second amplifier side from the first amplifier when the output power of the second amplifier is lower than saturation electric power, to impedance higher than impedance seen on the second amplifier side from the first amplifier when the output power of the second amplifier is equal to the saturation electric power.

An outphasing amplifier includes a first amplifier configured to amplify a first signal, a second amplifier configured to amplify a second signal of which a phase difference from the first signal changes, and a synthesizer that has a first transmission line through which a third signal output from the first amplifier passes, a second transmission line through which a fourth signal output from the second amplifier passes, a first coupling circuit that is separately provided from the first transmission line and is coupled to the first transmission line, a second coupling circuit that is separately provided from the second transmission line and coupled to the second transmission line, and a node that synthesizes the third signal having passed through the first transmission line and the fourth signal having passed through the second transmission line.

Aspects of the disclosure relate to devices, wireless communication apparatuses, methods, and circuitry implementing a low noise amplifier (LNA) with phase-shifting circuitry to achieve a continuous phase at the output of the LNA. One aspect is an amplifier including a high gain active path comprising active circuitry, and a low gain path comprising passive circuitry and phase-shifting circuitry. In one or more aspects, the phase-shifting circuitry is configured to shift a phase of an input signal within the low gain path such that the phase of an output signal outputted from the low gain path approximately matches a phase of an output signal outputted from the high gain active path. In at least one aspect, a gain of the high gain active path is higher than a gain of the low gain passive path.

Embodiments of RF amplifiers and packaged RF amplifier devices each include an amplification path with a transistor die, and an output-side impedance matching circuit having a T-match circuit topology. The output-side impedance matching circuit includes a first inductive element (e.g., first wirebonds) connected between the transistor output terminal and a quasi RF cold point node, a second inductive element (e.g., second wirebonds) connected between the quasi RF cold point node and an output of the amplification path, and a first capacitance connected between the quasi RF cold point node and a ground reference node. The RF amplifiers and devices also include a baseband termination circuit connected to the quasi RF cold point node, which includes an envelope resistor, an envelope inductor, and an envelope capacitor coupled in series between the quasi RF cold point node and the ground reference node.

Loss in a low-pass filter is reduced. A radio-frequency module includes an antenna terminal, a power amplifier, a low-noise amplifier, and a low-pass filter. The low-pass filter is disposed on a transmit path between the antenna terminal and the power amplifier and on a receive path between the antenna terminal and the low-noise amplifier. The low-pass filter has multiple paths. Each of the paths forms a part of either one or both of the transmit path and the receive path. The paths include a first path and a second path. The second path has a smaller reactance than the first path.

A transmission/reception module includes a substrate including a transmission signal input terminal, a reception signal output terminal, and an antenna terminal, an antenna switch circuit provided on the substrate and configured to output a transmission signal input from the transmission signal input terminal to the antenna terminal and configured to output a reception signal input from the antenna terminal to the reception signal output terminal, and a first inductor included in an input/output filter circuit provided between the antenna switch circuit and the antenna terminal. The first inductor includes a conductor whose winding axis direction is orthogonal to the substrate.

A power amplifier circuit includes: an amplifier that amplifies an input signal; and a resonant circuit that is connected to an output terminal of the amplifier and that attenuates a harmonic wave of an amplified signal obtained by amplifying the input signal. The resonant circuit includes an inductor disposed between the amplifier and a ground, a capacitive element disposed between the amplifier and the ground and connected in series to the inductor, an inductor connected in parallel to the inductor, a switch connected in series to the inductor, and a switch that is connected in parallel to the switch and that is of an element size common to an element size of the switch.

A reactance cancelling radio frequency (RF) circuit array is disclosed. The reactance cancelling RF circuit array includes multiple RF circuits each coupled to one or two adjacent RF circuits by one or two pairs of coupling mediums each having a respective length less than one-quarter wavelength. In one aspect, an RF input signal is first split across the RF circuits and then combined to form an RF output signal. As a result, each RF circuit requires a lower power handling capability to process a portion of the RF input signal. In another aspect, each pair of the coupling mediums can cause reactance cancellation in each reactance-cancelling pair of the RF circuits. By coupling the RF circuits via the coupling mediums and enabling splitting-combining among the RF circuits, it is possible to miniaturize the reactance cancelling RF circuit array for improved performance across a wide frequency spectrum.

A low noise amplifier includes a first input port configured to receive a first input signal, a second input port configured to receive a second input signal, and a first amplifier stage including a first gain stage connected to the first input port and the second input port, and a first drive stage between the first gain stage and a first load circuit. The first gain stage includes a first-first gain block connected to the first input port, a first-second gain block connected to the second input port, and a first degeneration inductor between a ground terminal and a first common node of the first-first gain block and the first-second gain block. The amplifier includes a second amplifier stage including a second gain stage connected to the first input port and the second input port, and a second drive stage between the second gain stage and a second load.

Optical amplification apparatus (1) for a submarine optical amplifier (90), the optical amplification apparatus (1) comprising an optical amplification system (2), comprising at least one active component (3), and a DC/DC converter (4) connected to supply the optical amplification system (2), wherein the DC/DC converter (4) comprises a first commutator (5) and a pulse modulator (6) connected to the first commutator (5) for cyclically switching with a duty cycle the first commutator (5) between a closing configuration, in which it can be passed thought by a current, and an opening configuration, in which it cannot be passed thought by the current, characterized in that the DC/DC converter (4) comprises a retroaction circuit (7) comprising, a first differential amplifier (8) connected for receiving, at a first input port, a first signal (100) representative of at least a voltage at output from the DC/DC converter (4) and at input into the optical amplification system (2) and, at a second input port, a first reference signal (201), the first differential amplifier (8) being structured for generating a first error signal (101) representative of a difference between the first signal (100) and the first reference signal (201), a second differential amplifier (9) connected to the first differential amplifier (8) for receiving, at a first respective input port, the first error signal (101) and, at a second respective input port, a second reference signal (201), the second differential amplifier (9) being structured for generating a second error signal (102) representative of a difference between the first error signal (101) and the second reference signal (201), wherein the second error signal (102) is proportional to a deviation of the voltage at output from the DC/DC converter (4) with respect to a nominal working voltage of the optical amplification system (2), in that the first input port of the first differential amplifier (8) and the first respective input port of the second differential amplifier (9) are concordant ports, and in that the pulse modulator (6) is connected to the second differential amplifier (9) for receiving the second error signal (102) and for regulating the duty cycle as a function of the second error signal (102).