Patent attributes
An amplification circuit includes an input terminal for receiving a radio frequency input signal, an output terminal for outputting an amplified radio frequency signal, a bias circuit for providing a bias voltage, an impedance circuit, a transistor, and a filter circuit. The impedance circuit is coupled to the bias circuit and the input terminal, and provides a voltage drop between the first terminal and the second terminal of the impedance circuit. The first transistor has a first terminal coupled to the output terminal, a second terminal coupled to a first reference voltage terminal, and a control terminal coupled to the impedance circuit and for receiving the radio frequency input signal. The filter circuit is coupled to the first transistor and the impedance circuit, filters out a harmonic signal, and provides a feedback signal including a primary frequency signal of the amplified radio frequency signal to the impedance circuit.