The present disclosure relates to a power amplifier circuit. The power amplifier circuit includes a voltage-controlled current source and a current mirror. The voltage-controlled current source is configured to receive a first voltage and to generate a first current. The current mirror is connected to the voltage-controlled current source and to generate a second current in response to the first current. The second current continuously changes from 0 mA to about 120 mA as the first voltage continuously changes from 0 V to about 1 V.

The present disclosure relates to a power amplifier circuit. The power amplifier circuit includes a voltage-controlled current source and a current mirror. The voltage-controlled current source is configured to receive a first voltage and to generate a first current. The current mirror is connected to the voltage-controlled current source and to generate a second current in response to the first current. The second current continuously changes from 0 mA to about 120 mA as the first voltage continuously changes from 0 V to about 1 V.

High frequency amplifier circuitry includes a common-source first transistor to amplify a high-frequency input signal, a common-gate second transistor cascade-connected to the first transistor, to amplify a signal amplified by the first transistor to generate an output signal, a first inductor connected between a source of the first transistor and a first reference potential node, a second inductor connected between a drain of the second transistor and a second reference potential node, and non-linear compensation circuitry connected to a connection node of the first transistor and the second transistor, to compensate for non-linearity of the output signal to the high-frequency input signal. The non-linear compensation circuitry has first rectifier circuitry, a first resistor, a second resistor, second rectifier circuitry, first capacitor and second capacitor.

High frequency amplifier circuitry includes a common-source first transistor to amplify a high-frequency input signal, a common-gate second transistor cascade-connected to the first transistor, to amplify a signal amplified by the first transistor to generate an output signal, a first inductor connected between a source of the first transistor and a first reference potential node, a second inductor connected between a drain of the second transistor and a second reference potential node, and non-linear compensation circuitry connected to a connection node of the first transistor and the second transistor, to compensate for non-linearity of the output signal to the high-frequency input signal. The non-linear compensation circuitry has first rectifier circuitry, a first resistor, a second resistor, second rectifier circuitry, first capacitor and second capacitor.

Various methods and circuital arrangements for biasing one or more gates of stacked transistors of an amplifier are possible where the amplifier is configured to operate in at least an active mode and a standby mode. Circuital arrangements can reduce bias circuit and stacked transistors standby current during operation in the standby mode and to reduce impedance presented to the gates of the stacked transistors during operation in the active mode while maintaining voltage compliance of the stacked transistors during both modes of operation.

Various methods and circuital arrangements for biasing one or more gates of stacked transistors of an amplifier are possible where the amplifier is configured to operate in at least an active mode and a standby mode. Circuital arrangements can reduce bias circuit and stacked transistors standby current during operation in the standby mode and to reduce impedance presented to the gates of the stacked transistors during operation in the active mode while maintaining voltage compliance of the stacked transistors during both modes of operation.

An amplifier for converting a single-ended input signal to a differential output signal. The amplifier comprises a first transistor, a second transistor, a third transistor and a fourth transistor. The first transistor, configured in common-source or common-emitter mode, receives the single-ended input signal and generates a first part of the differential output signal. The second transistor, also configured in common-source or common-emitter mode, generates a second part of the differential output signal. The third and fourth transistors are capacitively cross-coupled. The amplifier further comprises inductive degeneration such that a source or emitter of the first transistor is connected to a first inductor and a source or emitter of the second transistor is connected to a second inductor.

An amplifier for converting a single-ended input signal to a differential output signal. The amplifier comprises a first transistor, a second transistor, a third transistor and a fourth transistor. The first transistor, configured in common-source or common-emitter mode, receives the single-ended input signal and generates a first part of the differential output signal. The second transistor, also configured in common-source or common-emitter mode, generates a second part of the differential output signal. The third and fourth transistors are capacitively cross-coupled. The amplifier further comprises inductive degeneration such that a source or emitter of the first transistor is connected to a first inductor and a source or emitter of the second transistor is connected to a second inductor.

A gallium nitride based monolithic microwave integrated circuit includes a substrate, a channel layer on the substrate and a barrier layer on the channel layer. A recess is provided in a top surface of the barrier layer. First gate, source and drain electrodes are provided on the barrier layer opposite the channel layer, with a bottom surface of the first gate electrode in direct contact with the barrier layer. Second gate, source and drain electrodes are also provided on the barrier layer opposite the channel layer. A gate insulating layer is provided in the recess in the barrier layer, and the second gate electrode is on the gate insulating layer opposite the barrier layer and extending into the recess. The first gate, source and drain electrodes comprise the electrodes of a depletion mode transistor, and the second gate, source and drain electrodes comprise the electrodes of an enhancement mode transistor.

A current mirror circuit connectible to an amplifier circuit to set a bias point thereof includes a current mirror circuit, and a bias resistor connected thereto. The bias resistor is connectible to the amplifier circuit. A first helper circuit is connected in parallel with the bias resistor, and is selectively activated for a first predetermined duration by a first control signal. The activated first helper circuit defines a lower resistance path relative to the bias resistor to shorten a rising transient response of the amplifier circuit as the current mirror circuit is activated.