Amplifier device and duplexer circuit

An amplifier device, comprising:

• a first differential amplifier circuit, comprising:
• a first radio frequency input terminal, for inputting a first radio frequency input signal;
• a second radio frequency input terminal, for inputting a second radio frequency input signal;
• a first transistor, wherein a control terminal of which obtains the first radio frequency input signal through the first radio frequency input terminal, the first transistor amplifies the first radio frequency input signal and generates a first amplified radio frequency signal at a first terminal of the first transistor;
• a second transistor, wherein a control terminal of which obtains the second radio frequency input signal through the second radio frequency input terminal, the second transistor amplifies the second radio frequency input signal and generates a second amplified radio frequency signal at a first terminal of the second transistor;
• a first adjustable capacitor circuit, wherein a first terminal of which is coupled to the control terminal of the first transistor for receiving a first voltage, and a second terminal of which is coupled to the first terminal of the second transistor for receiving a second voltage, the first adjustable capacitor circuit is configured to couple the first radio frequency input signal to the first terminal of the second transistor, and a capacitance value of the first adjustable capacitor circuit is controlled by the first voltage and the second voltage;
• and
• a second adjustable capacitor circuit, wherein a first terminal of which is coupled to the control terminal of the second transistor for receiving a third voltage, and a second terminal of which is coupled to the first terminal of the first transistor for receiving a fourth voltage, the second adjustable capacitor circuit is configured for coupling the second radio frequency input signal to the first terminal of the first transistor, and a capacitance value of the second adjustable capacitor circuit is controlled by the third voltage and the fourth voltage;
• wherein the first amplified radio frequency signal is combined with the coupled second radio frequency input signal to form a first radio frequency output signal, and the second amplified radio frequency signal is combined with the coupled first radio frequency input signal to form a second radio frequency output signal;
• wherein the first voltage is related to the first radio frequency input signal, the second voltage is related to the second radio frequency output signal, the third voltage is related to the second radio frequency input signal, and the fourth voltage is related to the first radio frequency output signal.

A duplexer circuit, coupled to an antenna, the duplexer circuit comprising:

• a duplexer, comprising an antenna terminal, a signal transmitting terminal and a signal receiving terminal;
• a power amplifier, coupled to the signal transmitting terminal of the duplexer;
• a low noise amplifier, coupled to the signal receiving terminal of the duplexer;
• and
• an amplifier device, arranged in the power amplifier or the low noise amplifier, the amplifier device comprising:
• a first differential amplifier circuit, comprising:
• a first radio frequency input terminal, for inputting a first radio frequency input signal;
• a second radio frequency input terminal, for inputting a second radio frequency input signal;
• a first transistor, having a first terminal and a control terminal coupled to the first radio frequency input terminal, wherein the control terminal obtains the first radio frequency input signal through the first radio frequency input terminal, the first transistor amplifies the first radio frequency input signal and generates a first amplified radio frequency signal at the first terminal;
• a second transistor, having a first terminal and a control terminal coupled to the second radio frequency input terminal, wherein the control terminal obtains the second radio frequency input signal through the second radio frequency input terminal, the second transistor amplifies the second radio frequency input signal and generates a second amplified radio frequency signal at the first terminal;
• a first adjustable capacitor circuit, coupled between the control terminal of the first transistor and the first terminal of the second transistor, for coupling the first radio frequency input signal to the first terminal of the second transistor;
• and
• a second adjustable capacitor circuit, coupled between the control terminal of the second transistor and the first terminal of the first transistor, for coupling the second radio frequency input signal to the first terminal of the first transistor;
• a first radio frequency output terminal, coupled to the first terminal of the first transistor, for outputting a first radio frequency output signal;
• and
• a second radio frequency output terminal, coupled to the first terminal of the second transistor, for outputting a second radio frequency output signal,
• wherein the first amplified radio frequency signal is combined with the coupled second radio frequency input signal to form the first radio frequency output signal, and the second amplified radio frequency signal is combined with the coupled first radio frequency input signal to form the second radio frequency output signal;
• and
• a controller, coupled to the first adjustable capacitor circuit of the first differential amplifier circuit and the second adjustable capacitor circuit of the first differential amplifier circuit, configured to adjust capacitance values of the first adjustable capacitor circuit of the first differential amplifier circuit and the second adjustable capacitor circuit of the first differential amplifier circuit according to at least one of a characteristic related to the first radio frequency input signal of the first differential amplifier circuit, a characteristic related to the second radio frequency input signal of the first differential amplifier circuit, a matching deviation between the first transistor and the second transistor of the first differential amplifier circuit, and a characteristic of the amplifier device.