Amplifier circuits, radio communication circuits, radio communication devices, and methods provided in this disclosure provide an amplifier circuit. The amplifier circuit may include an amplifier configured to amplify an input signal to provide an output signal. The amplifier circuit may further include an amplifier stack including a first transistor coupled to the amplifier. The amplifier stack may be configured to receive the output signal to amplify the output signal. The amplifier stack may be configured to receive an input control signal to control the first transistor based on an envelope of the input signal.

An apparatus is disclosed for gain stabilization. In an example aspect, the apparatus includes an amplifier and a gain-stabilization circuit. The amplifier has a gain that is based on a bias voltage and an amplification control signal. The gain- stabilization circuit is coupled to the amplifier and includes a replica amplifier. The replica amplifier has a replica gain that is based on the bias voltage and the amplification control signal. The gain-stabilization circuit is configured to adjust at least one of the bias voltage or the amplification control signal based on a gain error associated with the replica amplifier.

A split-steer amplifier with an invertible phase output, includes a first transistor having its base coupled to a positive node of an input port, its emitter coupled to ground, and collector connected to a positive intermediate node; a second transistor having its base coupled to a negative node of the input port, its emitter coupled to ground, and collector connected to a negative intermediate node; and multiple output ports each having a transistor arrangement operable to couple a positive node of that output port to the positive intermediate node and a negative node of that output port to the negative intermediate node, operable to couple the positive node of that output port to the negative intermediate node and the negative node of that output port to the positive intermediate node, and operable to decouple the positive node and the negative node of that output port from the intermediate nodes.

A post driver includes an input pair circuit, a protection circuit, a common mode sensing circuit and an amplifier. The input pair circuit outputs a first signal through a first node and outputs a second signal through a second node according to a first input signal and a second input signal. The protection circuit provides the input pair circuit with voltage protection according to multiple first bias voltages and a second bias voltage, transmits the first signal to a first load to generate a first output signal, and transmits the second signal to a second load to generate a second output signal. The common mode sensing circuit senses a level of the first node and a level of the second node to generate a feedback signal. The amplifier generates the second bias voltage according to a reference signal and the feedback signal.

An electronic device including an amplifier which includes a first transistor configured to receive an input signal through a gate terminal thereof and having a source terminal electrically connected to ground, a second transistor configured to transmit an output signal through a drain terminal thereof and having a gate terminal electrically connected to the ground, and a switch electrically connected to the gate terminal of the second transistor and configured to switch a voltage being supplied to the gate terminal of the second transistor in accordance with turn-on or turn-off of the amplifier.

An apparatus has four transistors. The first and third transistors each have a gate coupled to a first input terminal and second input terminal respectively, a source coupled to a current source and to a first terminal of a bias voltage source, and a substrate coupled to a second terminal of the bias voltage source. The second and fourth transistors each have a gate coupled to the first input terminal and the second input terminal respectively, a source coupled to the drain of the first and third transistors respectively, a drain coupled to a lower voltage supply and a substrate coupled to its source. The bias voltage source increases the threshold voltages of the first and third transistors above the second and fourth transistors, respectively. This ensures that the first and third transistors turn on after the second and fourth transistors, respectively.

This application provides a variable gain amplifier and a phased array transceiver, to enable the variable gain amplifier to keep a phase constant when switching a gain, and to enable a gain step to be stable with a frequency. The variable gain amplifier includes an amplification circuit, configured to amplify an input signal; a control circuit, configured to control a gain of the amplification circuit by adjusting an output current of the amplification circuit; and an inductive load and an inductive adjustment circuit, where the inductive load is coupled to a signal output end of the amplification circuit, the inductive adjustment circuit and the inductive load are inductively coupled, and the inductive adjustment circuit is adjustable.

A split-steer amplifier with an invertible phase output, includes a first transistor having its base coupled to a positive node of an input port, its emitter coupled to ground, and collector connected to a positive intermediate node; a second transistor having its base coupled to a negative node of the input port, its emitter coupled to ground, and collector connected to a negative intermediate node; and multiple output ports each having a transistor arrangement operable to couple a positive node of that output port to the positive intermediate node and a negative node of that output port to the negative intermediate node, operable to couple the positive node of that output port to the negative intermediate node and the negative node of that output port to the positive intermediate node, and operable to decouple the positive node and the negative node of that output port from the intermediate nodes.

A system may include a front end differential amplifier having two input terminals, two input resistors, each of the two input resistors coupled to a respective one of the two input terminals, and an input common mode biasing circuit for an output stage of the front end differential amplifier, the input common mode biasing circuit comprising two current sources configured to generate currents for biasing the output stage of the front end differential amplifier.

A split-steer amplifier with an invertible phase output, includes a first transistor having its base coupled to a positive node of an input port, its emitter coupled to ground, and collector connected to a positive intermediate node; a second transistor having its base coupled to a negative node of the input port, its emitter coupled to ground, and collector connected to a negative intermediate node; and multiple output ports each having a transistor arrangement operable to couple a positive node of that output port to the positive intermediate node and a negative node of that output port to the negative intermediate node, operable to couple the positive node of that output port to the negative intermediate node and the negative node of that output port to the positive intermediate node, and operable to decouple the positive node and the negative node of that output port from the intermediate nodes.