Abstract: An amplifier circuit includes an amplifier, a detector and an adjustment circuit. The amplifier includes a first transistor and a bias voltage terminal. The first transistor includes a first terminal coupled to a first reference voltage terminal, a second terminal coupled to a second reference voltage terminal, and a control terminal coupled to the bias voltage terminal of the amplifier. The second transistor includes a first terminal coupled to a third reference voltage terminal and the detector, and a second terminal coupled to the second reference voltage terminal. The detector outputs a detection signal related to a characteristic parameter of the second transistor. The adjustment circuit is coupled to the detector and the bias voltage terminal of the amplifier for performing an adjustment operation according to the detection signal.

Abstract: An amplifier device includes an amplifying unit and a bias module. The amplifying unit has a first end coupled to a voltage source configured to receive a source voltage, a second end configured to receive an input signal, and a third end coupled to a first reference potential terminal configured to receive a first reference potential. The first end of the amplifying unit is configured to output an output signal amplified by the amplifying unit. The bias module is coupled to the second end of the amplifying unit, and configured to receive a voltage signal to generate a bias current according to a first counter-gradient and a second counter-gradient, and provide the bias current to the amplifying unit. The voltage signal is a variable voltage. A supply current flowing into the amplifying unit and is adjusted in accordance with the voltage signal to stay within a predetermined range.

Abstract: An amplifier device includes an amplifying unit and a bias module. The amplifying unit has a first end coupled to a voltage source configured to receive a source voltage, a second end configured to receive an input signal, and a third end coupled to a first reference potential terminal configured to receive a first reference potential. The first end of the amplifying unit is configured to output an output signal amplified by the amplifying unit. The bias module is coupled to the second end of the amplifying unit, and configured to receive a voltage signal to generate a bias current according to a first counter-gradient and a second counter-gradient, and provide the bias current to the amplifying unit. The voltage signal is a variable voltage. A supply current flowing into the amplifying unit and is adjusted in accordance with the voltage signal to stay within a predetermined range.

Abstract: An amplifier device comprises an amplifying unit and a bias module. The amplifying unit has a first end coupled to a voltage source configured to receive a source voltage, a second end configured to receive an input signal, and a third end coupled to a first reference potential terminal configured to receive a first reference potential. The first end of the amplifying unit is configured to output an output signal amplified by the amplifying unit. The bias module is coupled to the second end of the amplifying unit, and configured to receive a voltage signal to provide a bias current to the amplifying unit. The voltage signal is a variable voltage. A supply current flowing into the amplifying unit and is adjusted in accordance with the voltage signal to stay within a predetermined range.

Abstract: An impedance circuit includes a first impedance terminal, a second impedance terminal, a first transistor, a second transistor, a low frequency signal blocking element, and a current-voltage transform circuit. The first transistor is coupled to the first impedance terminal, and controlled by a first voltage. The second transistor is coupled to the first impedance terminal, and controlled by a second voltage. The low frequency signal blocking element is coupled to the first transistor and the second impedance terminal. The current-voltage transform circuit is coupled to the first impedance terminal. The current-voltage transform circuit adjusts a terminal voltage at the first terminal of the current-voltage transform circuit according to a current flowing through the current-voltage transform circuit. The impedance circuit provides impedance between the first and the second impedance terminals according to the terminal voltage and the first voltage.

Abstract: An amplifier device includes an amplifying unit, a bias module, an impedance unit and an adjusting module. The amplifying unit has a first end coupled to a voltage source and used for outputting an output signal amplified by the amplifying unit, a second end used for receiving an input signal, and a third end coupled to a first reference potential terminal. The bias module is coupled to the second end of the amplifying unit, and provides a bias voltage to the amplifying unit and adjusts linearity of the amplifier device according to a source voltage from the voltage source. The impedance unit is coupled to the bias module and used to receive a control voltage to adjust an impedance value of the impedance unit. The adjusting module is used to output the control voltage to the impedance unit according to the source voltage and a reference voltage.

Abstract: An amplifier device comprises an amplifying unit and a bias module. The amplifying unit has a first end coupled to a voltage source configured to receive a source voltage, a second end configured to receive an input signal, and a third end coupled to a first reference potential terminal configured to receive a first reference potential. The first end of the amplifying unit is configured to output an output signal amplified by the amplifying unit. The bias module is coupled to the second end of the amplifying unit, and configured to receive a voltage signal to provide a bias current to the amplifying unit. The voltage signal is a variable voltage. A supply current flowing into the amplifying unit and is adjusted in accordance with the voltage signal to stay within a predetermined range.

Abstract: An impedance circuit includes a first impedance terminal, a second impedance terminal, a first transistor, a second transistor, a low frequency signal blocking element, and a current-voltage transform circuit. The first transistor is coupled to the first impedance terminal, and controlled by a first voltage. The second transistor is coupled to the first impedance terminal, and controlled by a second voltage. The low frequency signal blocking element is coupled to the first transistor and the second impedance terminal. The current-voltage transform circuit is coupled to the first impedance terminal. The current-voltage transform circuit adjusts a terminal voltage at the first terminal of the current-voltage transform circuit according to a current flowing through the current-voltage transform circuit. The impedance circuit provides impedance between the first and the second impedance terminals according to the terminal voltage and the first voltage.

Abstract: An amplifier device includes an amplifying unit, a bias module, an impedance unit and an adjusting module. The amplifying unit has a first end coupled to a voltage source and used for outputting an output signal amplified by the amplifying unit, a second end used for receiving an input signal, and a third end coupled to a first reference potential terminal. The bias module is coupled to the second end of the amplifying unit, and provides a bias voltage to the amplifying unit and adjusts linearity of the amplifier device according to a source voltage from the voltage source. The impedance unit is coupled to the bias module and used to receive a control voltage to adjust an impedance value of the impedance unit. The adjusting module is used to output the control voltage to the impedance unit according to the source voltage and a reference voltage.