A Doherty amplifier circuit comprising: a splitter having: a splitter-input-terminal for receiving an input signal; a main-splitter-output-terminal; and a peaking-splitter-output-terminal; a main-power-amplifier having a main-power-input-terminal and a main-power-output-terminal, wherein; the main-power-input-terminal is connected to the main-splitter-output-terminal; and the main-power-output-terminal is configured to provide a main-power-amplifier-output-signal; a peaking-power-amplifier having a peaking-power-input-terminal and a peaking-power-output-terminal, wherein: the peaking-power-input-terminal is connected to the peaking-splitter-output-terminal; and the peaking-power-output-terminal is configured to provide a peaking-power-amplifier-output-signal. The splitter, the main-power-amplifier and the peaking-power-amplifier are provided by means of an integrated circuit.

A semiconductor device is provided with one or more gate fingers (20) that are provided in an active region on a semiconductor substrate (1), and a source finger (30) and a drain finger (40) that are provided in the active region and arranged alternately to allow each gate finger to be sandwiched between the source and drain fingers. The semiconductor device includes terminal circuit (60) that has inductive impedance at the frequency of a signal input to an input terminal of the one or more gate fingers, and is directly or indirectly connected to the one or more gate fingers at an area being spaced away from a connecting position of the input terminal (21a) of the one or more gate fingers (20).

Circuits, devices and methods related to antenna tuner. In some embodiments, an antenna can be tuned by amplifying a signal for transmission by operating a transistor with a base current, and monitoring the base current. The method can further include adjusting an antenna tuner to thereby adjust an antenna load impedance presented to the amplified signal, with the adjustment being based on a variation of the monitored base current.

Example multi-band phased array are described. One example multi-band phased array includes a plurality of branches coupled to a plurality of multi-band antennas. Each of the plurality of branches includes a low noise amplifier and a power amplifier. The power amplifier and the low noise amplifier are configured to transmit and receive, in a time-sharing manner, a signal of a first frequency band and a signal of a second frequency band that are received by the multi-band phased array, and the first frequency band and the second frequency band are different and do not overlap. Each of the plurality of branches further includes a phase shifter, where the phase shifter is configured to perform phase shifting on the signal of the first frequency band, and the phase shifter is further configured to perform phase shifting on the signal of the second frequency band.

When a signal source sends a radio-frequency signal to an input amplification circuit, a control circuit sends a first control signal to the input amplification circuit according to the frequency of the radio-frequency signal, the input amplification circuit receives the first control signal and forms an input oscillation loop, the radio-frequency signal forms an amplified first signal through the input oscillation loop, and the input amplification circuit sends the first signal to the output amplification circuit. According to the frequency of the radio-frequency signal, the control circuit transmits a second control signal to the output amplification circuit, which forms an output oscillation loop matched with the first signal. The first signal is amplified by the output oscillation loop to form an emitting signal, the output amplification circuit transmits the emitting signal to the emitting antenna for emitting, thereby improving the utilization ratio of a radio-frequency front end chip package.

An amplifier circuit to be used in a sonar is described. The amplifier circuit includes a transducer and a matching circuit. The transducer has an impedance characteristic having a resonance frequency and an anti-resonance frequency higher than the resonance frequency. The matching circuit is connected to the transducer. The impedance characteristic of the transducer connected to the matching circuit has a first resonance frequency and a second resonance frequency higher than the first resonance frequency.

A bias circuit of a power amplifier includes a first part circuit, a second part circuit and a power supply, in which the power supply is connected with a power supply end of the first part circuit; two ends of the first part circuit are connected in parallel with two ends of the second part circuit, and after parallel connection one end of a parallel circuit is connected with a gate of the first transistor of the power amplifier in a signal amplification circuit; the first part circuit is configured to provide a first bias voltage, and the second part circuit is configured to provide a second bias voltage; the two bias voltages are superimposed to provide a stable bias voltage; and an impedance of the bias circuit is in a preset range of the impedance.

Voltage ripple reduction in a power management circuit is disclosed. The power management circuit includes a power amplifier circuit configured to amplify a radio frequency (RF) signal based on a modulated voltage and an envelope tracking integrated circuit (ETIC) configured to provide the modulated voltage to the power amplifier circuit via a conductive path. Notably, an output impedance presenting at an input of the power amplifier circuit can interact with a modulated load current in the power amplifier circuit to create a voltage ripple in the modulated voltage to potentially cause an undesirable error in the RF signal. Herein, the ETIC is configured to modify the modulated voltage based on feedback of the voltage ripple in the modulated voltage. As such, it is possible to reduce the output impedance at the input of the power amplifier circuit to thereby reduce the voltage ripple in the modulated voltage.

In some implementations, there is provided an apparatus comprising a resonant amplifier circuit including a first inductor having a first inductive input and a first inductive output; a second inductor having a second inductive input and a second inductive output; a first switch coupled to the first inductive output; and a second switch coupled to the second inductive output, wherein the first switch and the second switched are driven out of phase, wherein the first inductor is configured to be resonant with a first capacitance associated with the first switch, and wherein the second inductor is configured to be resonant with a second capacitance associated with the second switch. Related systems and articles of manufacture are also provided.

A high-frequency signal transmission-reception circuit includes a plurality of band pass filter groups each including a plurality of band pass filter pairs; a first switch including a plurality of band pass filter-side terminal groups each including a plurality of band pass filter-side terminals, and an antenna-side terminal group; a plurality of couplers configured to output respective signal strengths of high-frequency signals transmitted on a plurality of transmission paths; and a second switch including an input terminal group electrically connected to the plurality of couplers, and an output terminal configured to output a detection signal output from one of the plurality of couplers. The first switch electrically connects one band pass filter-side terminal in one band pass filter-side terminal group and one antenna-side terminal, and also electrically connects one band pass filter-side terminal in another band pass filter-side terminal group and another antenna-side terminal.