An amplifying apparatus is provided, which includes a power-source main line, a plurality of amplifying control devices which include an amplifier, a power-source branch line, an over current protector. The amplifier amplifies a high-frequency signal. The power-source branch line is branched from the power-source main line. The over current protector disposed for the power-source branch line is connected to the amplifier and configured to disconnect the power-source branch line based on drive current flowing through the amplifier from the power-source branch line. The power-source main line is common to the plurality of amplifying control devices.

Certain aspects of the present disclosure provide an amplification system. The amplification system generally includes: a first amplifier having an output coupled to an output of the amplification system; a second amplifier, inputs of the first amplifier and the second amplifier being coupled to an input of the amplification system; an impedance coupled to an output of the second amplifier; and a biasing circuit having a first voltage sense input coupled to the output of the first amplifier, a second voltage sense input coupled to the output of the second amplifier, and an output coupled to a bias input of the first amplifier.

Load current consumption measured using a first resistor having a high resistive value and a second resistor having a low resistive value. Differential amplifiers, the outputs of which are coupled to analog-to-digital converters and to a processing circuit unit, are connected to each of the nodes of the resistors. Depending on the current level, the processing circuit unit advantageously selects one of the analog-to-digital converters to estimate the present consumption of current in the load. Each input terminal of a resistor is advantageously power supplied from a power amplifier and each power amplifier is advantageously driven by a control loop. For low load currents, the first amplifier associated with the first resistor power supplies the load through the resistors while, for high load currents, when this first amplifier saturates, the second amplifier associated with the second resistor, takes over from the first amplifier to continue to power supply the load.

A high-frequency device includes a metal base, a dielectric substrate mounted on the metal base, an insulator layer provided on the metal base, covering the dielectric substrate, and having a dielectric constant smaller than that of the dielectric substrate, and a first line that overlaps the dielectric substrate as seen from a thickness direction of the insulator layer and is provided on an upper surface of the insulator layer to form a first microstrip line.

Disclosed is an amplifier having a carrier amplifier configured as a common-emitter carrier power stage and a peaking amplifier configured as a common-emitter peaking power stage. Further included is power adaptive biasing circuitry coupled between the carrier amplifier and the peaking amplifier, wherein the power adaptive biasing circuitry is configured to sense direct current base voltages of the common-emitter carrier power stage and to generate control currents that debias the common-emitter carrier power stage in response to the current base voltages of the common-emitter carrier power stage.

An amplifier circuit 1001 with a variable temperature coefficient of a gain is an amplifier circuit with a variable temperature coefficient of a gain in which a variable resistor VR is connected between a first signal and a second signal having temperature coefficients of an amplification factor different from each other, a variable output of the variable resistor VR is connected to an input of a buffer amplifier Ub, and an output of the buffer amplifier Ub is used as an output Vo, wherein the first signal is an output of a first temperature coefficient circuit 100, and the second signal is an output of another amplifier circuit 501.

Systems and methods for calibrating a wireless power transmitter is described. A wireless power transmitter can include a controller and an amplifier module. The amplifier module can include an amplifier configured to amplify a voltage converted from a current proportional to power consumed by a wireless power transmitter, and a circuit connected to the amplifier. The circuit can be configured to receive a control signal from the controller. The circuit can be further configured to perform time division multiplexing on an output of the amplifier according to the control signal. A time division multiplexed output of the amplifier can include calibration data of the amplifier. The amplifier can be configured to output the time division multiplexed output to the controller.

Systems, methods and apparatus for practical realization of an integrated circuit comprising a stack of transistors operating as an RF amplifier are described. As stack height is increased, capacitance values of gate capacitors used to provide a desired distribution of an RF voltage at the output of the amplifier across the stack may decrease to values approaching parasitic/stray capacitance values present in the integrated circuit which may render the practical realization of the integrated circuit difficult. Coupling of an RF gate voltage at the gate of one transistor of the stack to a gate of a different transistor of the stack can allow for an increase in the capacitance value of the gate capacitor of the different transistor for obtaining an RF voltage at the gate of the different transistor according to the desired distribution.

Example embodiments relate to Doherty amplifiers. One Doherty amplifier includes a packaged main amplifier that includes a main input lead for receiving a main RF signal, a main power transistor for amplifying the main RF signal, and a main output lead for outputting the main RF signal amplified by the main power transistor. The Doherty amplifier also includes a packaged peak amplifier that includes a peak input lead assembly for receiving a peak RF a first peak power transistor configured for amplifying a part of the peak RF signal, a second peak power transistor configured for amplifying a remaining part of the peak RF signal, and a peak output lead for combining the part of the peak RF signal amplified by the first peak power transistor and the remaining part of the peak RF signal amplified by the second peak power transistor into an amplified peak RF signal.

Example embodiments relate to radiofrequency, RF, amplifiers and electronic devices that include RF amplifiers. One example RF amplifier includes a splitter configured to split an RF input signal received at an input of the RF amplifier into a plurality of RF signal parts. The RF amplifier also includes a plurality of Doherty amplifiers, each Doherty amplifier having a main amplifier and a peak amplifier. Each Doherty amplifier is configured to amplify a respective RF signal part and output a respective amplified RF signal part. Additionally, the RF amplifier includes a combiner. The combiner is configured to combine the amplified RF signal parts from the plurality of Doherty amplifiers into an RF output signal and output the RE output signal. The combiner includes a plurality of inputs and an output. Each input of the combiner is connected to an output of a respective Doherty amplifier among the plurality of Doherty amplifiers.